Code cleanup (#12333)

- removed unused private methods
- removed unused private variables
- removed unnecessary initializations
- removed unnecessary substring(0)
- removed inner assignments
- renamed private methods that started with upper case
- renamed static final variables to use upper case
- converted to use non-deprecated options
- suppressed unavoidable warnings
- divided long Strings to multiple lines
- added missing types
- added missing JavaDoc parameters
- formatting
- updated comments & JavaDocs

client-compiler/src/main/java/com/vaadin/server/widgetsetutils/AcceptCriteriaFactoryGenerator.java

@@ -39,6 +39,7 @@ import com.vaadin.shared.ui.dd.AcceptCriterion;
  * classpath.
  *
  */
+@SuppressWarnings("deprecation")
 public class AcceptCriteriaFactoryGenerator extends Generator {
 
     private String packageName;
@@ -75,8 +76,8 @@ public class AcceptCriteriaFactoryGenerator extends Generator {
      */
     private void generateClass(TreeLogger logger, GeneratorContext context) {
         // get print writer that receives the source code
-        PrintWriter printWriter = null;
-        printWriter = context.tryCreate(logger, packageName, className);
+        PrintWriter printWriter = context.tryCreate(logger, packageName,
+                className);
         // print writer if null, source code has ALREADY been generated,
         // return (WidgetMap is equal to all permutations atm)
         if (printWriter == null) {
@@ -86,8 +87,8 @@ public class AcceptCriteriaFactoryGenerator extends Generator {
         Date date = new Date();
 
         // init composer, set class properties, create source writer
-        ClassSourceFileComposerFactory composer = null;
-        composer = new ClassSourceFileComposerFactory(packageName, className);
+        ClassSourceFileComposerFactory composer = new ClassSourceFileComposerFactory(
+                packageName, className);
         composer.addImport("com.google.gwt.core.client.GWT");
         composer.setSuperclass(
                 "com.vaadin.client.ui.dd.VAcceptCriterionFactory");

client-compiler/src/main/java/com/vaadin/server/widgetsetutils/ConnectorBundleLoaderFactory.java

@@ -511,16 +511,16 @@ public class ConnectorBundleLoaderFactory extends Generator {
         writeInvokers(logger, w, bundle);
         writeParamTypes(w, bundle);
         writeProxys(w, bundle);
-        writeMethodAttributes(logger, w, bundle);
+        writeMethodAttributes(w, bundle);
 
         w.println("%s(store);", loadNativeJsMethodName);
 
         // Must use Java code to generate Type data (because of Type[]), doing
         // this after the JS property data has been initialized
-        writePropertyTypes(logger, w, bundle);
+        writePropertyTypes(w, bundle);
         writeSerializers(logger, w, bundle);
         writePresentationTypes(w, bundle);
-        writeDelegateToWidget(logger, w, bundle);
+        writeDelegateToWidget(w, bundle);
         writeOnStateChangeHandlers(logger, w, bundle);
     }
 
@@ -652,8 +652,8 @@ public class ConnectorBundleLoaderFactory extends Generator {
         }
     }
 
-    private void writeDelegateToWidget(TreeLogger logger,
-            SplittingSourceWriter w, ConnectorBundle bundle) {
+    private void writeDelegateToWidget(SplittingSourceWriter w,
+            ConnectorBundle bundle) {
         Map<JClassType, Set<Property>> needsDelegateToWidget = bundle
                 .getNeedsDelegateToWidget();
         for (Entry<JClassType, Set<Property>> entry : needsDelegateToWidget
@@ -713,7 +713,7 @@ public class ConnectorBundleLoaderFactory extends Generator {
         }
     }
 
-    private void writePropertyTypes(TreeLogger logger, SplittingSourceWriter w,
+    private void writePropertyTypes(SplittingSourceWriter w,
             ConnectorBundle bundle) {
         Set<Property> properties = bundle.getNeedsProperty();
         for (Property property : properties) {
@@ -729,8 +729,8 @@ public class ConnectorBundleLoaderFactory extends Generator {
         }
     }
 
-    private void writeMethodAttributes(TreeLogger logger,
-            SplittingSourceWriter w, ConnectorBundle bundle) {
+    private void writeMethodAttributes(SplittingSourceWriter w,
+            ConnectorBundle bundle) {
         for (Entry<JClassType, Map<JMethod, Set<MethodAttribute>>> typeEntry : bundle
                 .getMethodAttributes().entrySet()) {
             JClassType type = typeEntry.getKey();
@@ -879,7 +879,7 @@ public class ConnectorBundleLoaderFactory extends Generator {
                     TreeLogger methodLogger = typeLogger.branch(Type.DEBUG,
                             "Invoking " + method.getName() + " using jsni");
                     // Must use JSNI to access non-public methods
-                    writeJsniInvoker(methodLogger, w, type, method);
+                    writeJsniInvoker(methodLogger, w, method);
                 }
 
                 w.println(");");
@@ -890,7 +890,7 @@ public class ConnectorBundleLoaderFactory extends Generator {
     }
 
     private void writeJsniInvoker(TreeLogger logger, SplittingSourceWriter w,
-            JClassType type, JMethod method) throws UnableToCompleteException {
+            JMethod method) throws UnableToCompleteException {
         w.println("new JsniInvoker() {");
         w.indent();
 

client-compiler/src/main/java/com/vaadin/server/widgetsetutils/metadata/MethodProperty.java

@@ -53,7 +53,7 @@ public class MethodProperty extends Property {
         Set<String> getters = new HashSet<>();
         List<JMethod> setters = getSetters(type, getters);
         for (JMethod setter : setters) {
-            String getter = findGetter(type, setter);
+            String getter = findGetter(setter);
             properties.add(new MethodProperty(setter.getEnclosingType(), setter,
                     getters.contains(getter) ? getter : null));
         }
@@ -118,8 +118,7 @@ public class MethodProperty extends Property {
 
     }
 
-    private static String findGetter(JClassType beanType,
-            JMethod setterMethod) {
+    private static String findGetter(JMethod setterMethod) {
         JType setterParameterType = setterMethod.getParameterTypes()[0];
         String fieldName = setterMethod.getName().substring(3);
         if (setterParameterType.getQualifiedSourceName()

client/src/main/java/com/vaadin/client/communication/JsonEncoder.java

@@ -49,15 +49,25 @@ import elemental.json.JsonValue;
  */
 public class JsonEncoder {
 
+    private JsonEncoder() {
+        // private constructor to prevent initialization
+    }
+
     /**
      * Encode a value to a JSON representation for transport from the client to
      * the server.
      *
      * @param value
      *            value to convert
+     * @param type
+     *            type information, not needed for all encoding tasks, such as
+     *            encoding a String
      * @param connection
+     *            application connection providing the context, not needed for
+     *            all encoding tasks, such as encoding a String
      * @return JSON representation of the value
      */
+    @SuppressWarnings("unchecked")
     public static JsonValue encode(Object value, Type type,
             ApplicationConnection connection) {
         if (null == value) {
@@ -80,17 +90,17 @@ public class JsonEncoder {
         } else if (value instanceof Character) {
             return Json.create(String.valueOf(value));
         } else if (value instanceof Object[] && type == null) {
-            // Non-legacy arrays handed by generated serializer
+            // Non-legacy arrays handled by generated serializer
             return encodeLegacyObjectArray((Object[]) value, connection);
         } else if (value instanceof Enum) {
-            return encodeEnum((Enum<?>) value, connection);
+            return encodeEnum((Enum<?>) value);
         } else if (value instanceof Map) {
-            return encodeMap((Map) value, type, connection);
+            return encodeMap((Map<Object, Object>) value, type, connection);
         } else if (value instanceof Connector) {
             Connector connector = (Connector) value;
             return Json.create(connector.getConnectorId());
         } else if (value instanceof Collection) {
-            return encodeCollection((Collection) value, type, connection);
+            return encodeCollection((Collection<?>) value, type, connection);
         } else if (value instanceof UidlValue) {
             return encodeVariableChange((UidlValue) value, connection);
         } else {
@@ -254,8 +264,7 @@ public class JsonEncoder {
         return jsonMap;
     }
 
-    private static JsonValue encodeEnum(Enum<?> e,
-            ApplicationConnection connection) {
+    private static JsonValue encodeEnum(Enum<?> e) {
         return Json.create(e.toString());
     }
 
@@ -270,8 +279,8 @@ public class JsonEncoder {
         return jsonArray;
     }
 
-    private static JsonArray encodeCollection(Collection collection, Type type,
-            ApplicationConnection connection) {
+    private static JsonArray encodeCollection(Collection<?> collection,
+            Type type, ApplicationConnection connection) {
         JsonArray jsonArray = Json.createArray();
         int idx = 0;
         for (Object o : collection) {

client/src/main/java/com/vaadin/client/connectors/grid/DetailsManagerConnector.java

@@ -54,11 +54,12 @@ import elemental.json.JsonObject;
  * @author Vaadin Ltd
  * @since 8.0
  */
+@SuppressWarnings("deprecation")
 @Connect(DetailsManager.class)
 public class DetailsManagerConnector extends AbstractExtensionConnector {
 
     /* Map for tracking which details are open on which row */
-    private TreeMap<Integer, String> indexToDetailConnectorId = new TreeMap<>();
+    private Map<Integer, String> indexToDetailConnectorId = new TreeMap<>();
     /* For listening data changes that originate from DataSource. */
     private Registration dataChangeRegistration;
     /* For listening spacer index changes that originate from Escalator. */
@@ -266,7 +267,6 @@ public class DetailsManagerConnector extends AbstractExtensionConnector {
     /**
      * Height aware details generator for client-side Grid.
      */
-    @SuppressWarnings("deprecation")
     private class CustomDetailsGenerator
             implements HeightAwareDetailsGenerator {
 

client/src/main/java/com/vaadin/client/debug/internal/AnalyzeLayoutsPanel.java

@@ -44,6 +44,7 @@ import com.vaadin.client.ValueMap;
  *
  * @since 7.1.4
  */
+@SuppressWarnings("deprecation")
 public class AnalyzeLayoutsPanel extends FlowPanel {
 
     private List<SelectConnectorListener> listeners = new ArrayList<>();
@@ -88,19 +89,19 @@ public class AnalyzeLayoutsPanel extends FlowPanel {
                     + "states, but reported here as they might be.</em>"));
             if (!zeroHeightComponents.isEmpty()) {
                 add(new HTML("<p><strong>Vertically zero size:</strong></p>"));
-                printClientSideDetectedIssues(zeroHeightComponents, ac);
+                printClientSideDetectedIssues(zeroHeightComponents);
             }
             if (!zeroWidthComponents.isEmpty()) {
                 add(new HTML(
                         "<p><strong>Horizontally zero size:</strong></p>"));
-                printClientSideDetectedIssues(zeroWidthComponents, ac);
+                printClientSideDetectedIssues(zeroWidthComponents);
             }
         }
 
     }
 
     private void printClientSideDetectedIssues(
-            Set<ComponentConnector> zeroSized, ApplicationConnection ac) {
+            Set<ComponentConnector> zeroSized) {
 
         // keep track of already highlighted parents
         HashSet<String> parents = new HashSet<>();

client/src/main/java/com/vaadin/client/ui/TouchScrollDelegate.java

@@ -456,14 +456,14 @@ public class TouchScrollDelegate implements NativePreviewHandler {
                 }
                 deltaScrollTop = overscroll - origScrollTop;
             }
-            quickSetScrollPosition(0, deltaScrollTop);
+            quickSetScrollPosition(deltaScrollTop);
             moved = true;
             event.preventDefault();
             event.stopPropagation();
         }
     }
 
-    private void quickSetScrollPosition(int deltaX, int deltaY) {
+    private void quickSetScrollPosition(int deltaY) {
         deltaScrollPos = deltaY;
         if (ANDROID_WITH_BROKEN_SCROLL_TOP) {
             deltaY += origScrollTop;
@@ -500,7 +500,7 @@ public class TouchScrollDelegate implements NativePreviewHandler {
                 : Math.abs(origY - lastClientY) >= SIGNIFICANT_MOVE_THRESHOLD;
     }
 
-    private void onTouchEnd(NativeEvent event) {
+    private void onTouchEnd() {
         if (!moved) {
             activeScrollDelegate = null;
             handlerRegistration.removeHandler();
@@ -532,17 +532,14 @@ public class TouchScrollDelegate implements NativePreviewHandler {
             if (pixelsPerMs < 0) {
                 pixelsToMove = -pixelsToMove;
             }
-            // getLogger().info("pixels to move" + pixelsToMove);
 
             finalY = currentY + pixelsToMove;
 
             if (finalY > maxFinalY + getMaxOverScroll()) {
-                // getLogger().info("To max overscroll");
                 finalY = getMaxFinalY() + getMaxOverScroll();
                 int fixedPixelsToMove = finalY - currentY;
                 pixelsToMove = fixedPixelsToMove;
             } else if (finalY < 0 - getMaxOverScroll()) {
-                // getLogger().info("to min overscroll");
                 finalY = -getMaxOverScroll();
                 int fixedPixelsToMove = finalY - currentY;
                 pixelsToMove = fixedPixelsToMove;
@@ -552,7 +549,7 @@ public class TouchScrollDelegate implements NativePreviewHandler {
         }
         if (duration == -1) {
             // did not keep in side borders or was outside borders, calculate
-            // a good enough duration based on pixelsToBeMoved.
+            // a good enough duration based on pixelsToMove.
             duration = getAnimationTimeForDistance(pixelsToMove);
         }
         if (duration > MAX_DURATION) {
@@ -690,7 +687,7 @@ public class TouchScrollDelegate implements NativePreviewHandler {
                 if (moved) {
                     event.cancel();
                 }
-                onTouchEnd(event.getNativeEvent());
+                onTouchEnd();
             }
             break;
         case Event.ONMOUSEMOVE:

client/src/main/java/com/vaadin/client/ui/VAbstractCalendarPanel.java

@@ -97,14 +97,16 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      */
     public interface FocusOutListener {
         /**
+         * @param event
+         *            dom event
          * @return true if the calendar panel is not used after focus moves out
          */
         boolean onFocusOut(DomEvent<?> event);
     }
 
     /**
-     * FocusChangeListener is notified when the panel changes its _focused_
-     * value.
+     * FocusChangeListener is notified when the panel changes its
+     * {@code focused} value.
      */
     public interface FocusChangeListener {
         void focusChanged(Date focusedDate);
@@ -183,6 +185,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      * Represents a click handler for when a user selects a value by using the
      * mouse
      */
+    @SuppressWarnings("unchecked")
     private ClickHandler dayClickHandler = event -> {
         if (!isEnabled() || isReadonly()) {
             return;
@@ -231,6 +234,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      *            A Date representing the day of month to be focused. Must be
      *            one of the days currently visible.
      */
+    @SuppressWarnings("unchecked")
     private void focusDay(Date date) {
         // Only used when calendar body is present
         if (acceptDayFocus()) {
@@ -350,6 +354,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      *            one of the days currently visible.
      *
      */
+    @SuppressWarnings("unchecked")
     private void selectDate(Date date) {
         if (selectedDay != null) {
             selectedDay.removeStyleDependentName(CN_SELECTED);
@@ -765,7 +770,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
         // If dateStrResolution has more year digits than rangeEnd, we need
         // to pad it in order to be lexicographically compatible
         String dateStrResolution = dateStrResolution(date, minResolution);
-        String paddedEnd = rangeEnd.substring(0);
+        String paddedEnd = rangeEnd;
         int yearDigits = dateStrResolution.indexOf("-");
         if (yearDigits == -1) {
             yearDigits = dateStrResolution.length();
@@ -777,21 +782,6 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
                 .compareTo(dateStrResolution) >= 0;
     }
 
-    private static Date clearDateBelowMonth(Date date) {
-        date.setDate(1);
-        return clearDateBelowDay(date);
-    }
-
-    private static Date clearDateBelowDay(Date date) {
-        date.setHours(0);
-        date.setMinutes(0);
-        date.setSeconds(0);
-        // Clearing milliseconds
-        long time = date.getTime() / 1000;
-        date = new Date(time * 1000);
-        return date;
-    }
-
     /**
      * Builds the day and time selectors of the calendar.
      */
@@ -952,9 +942,12 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
     }
 
     /**
-     * Returns the value of initialRenderDone
+     * Returns the value of initialRenderDone.
      *
      * @since 8.7
+     *
+     * @return {@code true} if the initial render has been marked as done,
+     *         {@code false} otherwise
      */
     public boolean isInitialRenderDone() {
         return initialRenderDone;
@@ -1386,7 +1379,8 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      *            Was the ctrl key pressed?
      * @param shift
      *            Was the shift key pressed?
-     * @return
+     * @return {@code true} if the navigation was handled successfully,
+     *         {@code false} otherwise
      */
     protected boolean handleNavigationMonthMode(int keycode, boolean ctrl,
             boolean shift) {
@@ -1572,7 +1566,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      * selection. By default this is backspace but it can be overridden to
      * change the key to whatever you want.
      *
-     * @return
+     * @return the reset key
      */
     protected int getResetKey() {
         return KeyCodes.KEY_BACKSPACE;
@@ -1583,7 +1577,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      * enter key but it can be changed to whatever you like by overriding this
      * method.
      *
-     * @return
+     * @return the select key
      */
     protected int getSelectKey() {
         return KeyCodes.KEY_ENTER;
@@ -1594,7 +1588,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      * Else this does nothing. By default this is the Escape key but you can
      * change the key to whatever you want by overriding this method.
      *
-     * @return
+     * @return the closing key
      */
     protected int getCloseKey() {
         return KeyCodes.KEY_ESCAPE;
@@ -1605,7 +1599,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      * right arrow key but by overriding this method it can be changed to
      * whatever you like.
      *
-     * @return
+     * @return the forward key
      */
     protected int getForwardKey() {
         return KeyCodes.KEY_RIGHT;
@@ -1616,7 +1610,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      * the left arrow key but by overriding this method it can be changed to
      * whatever you like.
      *
-     * @return
+     * @return the backward key
      */
     protected int getBackwardKey() {
         return KeyCodes.KEY_LEFT;
@@ -1627,7 +1621,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      * the down arrow key but by overriding this method it can be changed to
      * whatever you like.
      *
-     * @return
+     * @return the next week key
      */
     protected int getNextKey() {
         return KeyCodes.KEY_DOWN;
@@ -1638,7 +1632,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      * is the up arrow key but by overriding this method it can be changed to
      * whatever you like.
      *
-     * @return
+     * @return the previous week key
      */
     protected int getPreviousKey() {
         return KeyCodes.KEY_UP;
@@ -1665,6 +1659,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      * com.google.gwt.event.dom.client.MouseDownHandler#onMouseDown(com.google
      * .gwt.event.dom.client.MouseDownEvent)
      */
+    @SuppressWarnings("unchecked")
     @Override
     public void onMouseDown(MouseDownEvent event) {
         // Click-n-hold the left mouse button for fast-forward or fast-rewind.
@@ -1721,8 +1716,9 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
     }
 
     private Date parseRangeString(String dateStr) {
-        if (dateStr == null || "".equals(dateStr))
+        if (dateStr == null || "".equals(dateStr)) {
             return null;
+        }
         int year = Integer.parseInt(dateStr.substring(0, 4)) - 1900;
         int month = parsePart(dateStr, 5, 2, 1) - 1;
         int day = parsePart(dateStr, 8, 2, 1);
@@ -1735,8 +1731,9 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
 
     private int parsePart(String dateStr, int beginIndex, int length,
             int defValue) {
-        if (dateStr.length() < beginIndex + length)
+        if (dateStr.length() < beginIndex + length) {
             return defValue;
+        }
         return Integer
                 .parseInt(dateStr.substring(beginIndex, beginIndex + length));
     }
@@ -1807,7 +1804,8 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
                     value = null;
                 }
             } else {
-                focusedDate = displayedMonth = null;
+                displayedMonth = null;
+                focusedDate = null;
             }
         } else {
             focusedDate = new FocusedDate(value.getYear(), value.getMonth(),
@@ -1854,11 +1852,12 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
     }
 
     /**
-     * If true should be returned if the panel will not be used after this
-     * event.
+     * True should be returned if the panel will not be used after this event.
      *
      * @param event
-     * @return
+     *            dom event
+     * @return {@code true} if the panel will not be used after this event,
+     *         {@code false} otherwise
      */
     protected boolean onTabOut(DomEvent<?> event) {
         if (focusOutListener != null) {
@@ -1949,10 +1948,6 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
 
     private static final String SUBPART_NEXT_YEAR = "nexty";
     private static final String SUBPART_PREV_YEAR = "prevy";
-    private static final String SUBPART_HOUR_SELECT = "h";
-    private static final String SUBPART_MINUTE_SELECT = "m";
-    private static final String SUBPART_SECS_SELECT = "s";
-    private static final String SUBPART_AMPM_SELECT = "ampm";
     private static final String SUBPART_DAY = "day";
     private static final String SUBPART_MONTH_YEAR_HEADER = "header";
 
@@ -1999,8 +1994,11 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      * Checks if subElement is inside the widget DOM hierarchy.
      *
      * @param w
+     *            the widget to investigate
      * @param subElement
-     * @return true if {@code w} is a parent of subElement, false otherwise.
+     *            the element to search for
+     * @return {@code true} if the given widget is a parent of the given
+     *         element, {@code false} otherwise.
      */
     protected boolean contains(Widget w, Element subElement) {
         if (w == null || w.getElement() == null) {
@@ -2010,6 +2008,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
         return w.getElement().isOrHasChild(subElement);
     }
 
+    @SuppressWarnings("unchecked")
     @Override
     public com.google.gwt.user.client.Element getSubPartElement(
             String subPart) {
@@ -2132,8 +2131,8 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
      */
     public void setRangeEnd(String newRangeEnd) {
         if (!SharedUtil.equals(rangeEnd, newRangeEnd)) {
-            // Dates with year 10000 or more has + prefix, which is not compatible
-            // with format returned by dateStrResolution method
+            // Dates with year 10000 or more has + prefix, which is not
+            // compatible with format returned by dateStrResolution method
             if (newRangeEnd.startsWith("+")) {
                 rangeEnd = newRangeEnd.substring(1);
             } else {

client/src/main/java/com/vaadin/client/ui/combobox/ComboBoxConnector.java

@@ -17,7 +17,6 @@ package com.vaadin.client.ui.combobox;
 
 import java.util.List;
 import java.util.Objects;
-import java.util.logging.Logger;
 
 import com.vaadin.client.Profiler;
 import com.vaadin.client.annotations.OnStateChange;
@@ -487,9 +486,6 @@ public class ComboBoxConnector extends AbstractListingConnector
         }
     }
 
-    private static final Logger LOGGER = Logger
-            .getLogger(ComboBoxConnector.class.getName());
-
     private class PagedDataChangeHandler implements DataChangeHandler {
 
         private final DataSource<?> dataSource;

client/src/main/java/com/vaadin/client/ui/dd/DragAndDropHandler.java

@@ -116,11 +116,11 @@ public class DragAndDropHandler {
                 // End drag if ESC is pressed
                 int keyCode = event.getNativeEvent().getKeyCode();
                 if (keyCode == KeyCodes.KEY_ESCAPE) {
-                    cancelDrag(event);
+                    cancelDrag();
                 }
                 break;
             case Event.ONTOUCHCANCEL:
-                cancelDrag(event);
+                cancelDrag();
                 break;
             case Event.ONTOUCHEND:
             case Event.ONMOUSEUP:
@@ -236,7 +236,7 @@ public class DragAndDropHandler {
         }
     }
 
-    private void cancelDrag(NativePreviewEvent event) {
+    private void cancelDrag() {
         callback.onDragCancel();
         callback.onDragEnd();
         stopDrag();

client/src/main/java/com/vaadin/client/ui/orderedlayout/VAbstractOrderedLayout.java

@@ -491,6 +491,7 @@ public class VAbstractOrderedLayout extends FlowPanel {
      * Assigns relative sizes to the children that should expand based on their
      * expand ratios.
      */
+    @SuppressWarnings("deprecation")
     public void updateExpandedSizes() {
         // Ensure the expand wrapper is in place
         if (expandWrapper == null) {
@@ -651,8 +652,7 @@ public class VAbstractOrderedLayout extends FlowPanel {
                                 totalSize += size;
                             }
                         } else {
-                            int max = -1;
-                            max = layoutManager.getOuterWidth(
+                            int max = layoutManager.getOuterWidth(
                                     slot.getWidget().getElement());
                             if (slot.hasCaption()) {
                                 int max2 = layoutManager.getOuterWidth(

client/src/main/java/com/vaadin/client/widgets/Escalator.java

@@ -764,13 +764,13 @@ public class Escalator extends Widget
         /*-{
             var vScroll = esc.@com.vaadin.client.widgets.Escalator::verticalScrollbar;
             var vScrollElem = vScroll.@com.vaadin.client.widget.escalator.ScrollbarBundle::getElement()();
-        
+
             var hScroll = esc.@com.vaadin.client.widgets.Escalator::horizontalScrollbar;
             var hScrollElem = hScroll.@com.vaadin.client.widget.escalator.ScrollbarBundle::getElement()();
-        
+
             return $entry(function(e) {
                 var target = e.target;
-        
+
                 // in case the scroll event was native (i.e. scrollbars were dragged, or
                 // the scrollTop/Left was manually modified), the bundles have old cache
                 // values. We need to make sure that the caches are kept up to date.
@@ -791,29 +791,29 @@ public class Escalator extends Widget
             return $entry(function(e) {
                 var deltaX = e.deltaX ? e.deltaX : -0.5*e.wheelDeltaX;
                 var deltaY = e.deltaY ? e.deltaY : -0.5*e.wheelDeltaY;
-        
+
                 // Delta mode 0 is in pixels; we don't need to do anything...
-        
+
                 // A delta mode of 1 means we're scrolling by lines instead of pixels
                 // We need to scale the number of lines by the default line height
                 if (e.deltaMode === 1) {
                     var brc = esc.@com.vaadin.client.widgets.Escalator::body;
                     deltaY *= brc.@com.vaadin.client.widgets.Escalator.AbstractRowContainer::getDefaultRowHeight()();
                 }
-        
+
                 // Other delta modes aren't supported
                 if ((e.deltaMode !== undefined) && (e.deltaMode >= 2 || e.deltaMode < 0)) {
                     var msg = "Unsupported wheel delta mode \"" + e.deltaMode + "\"";
-        
+
                     // Print warning message
                     esc.@com.vaadin.client.widgets.Escalator::logWarning(*)(msg);
                 }
-        
+
                 // IE8 has only delta y
                 if (isNaN(deltaY)) {
                     deltaY = -0.5*e.wheelDelta;
                 }
-        
+
                 @com.vaadin.client.widgets.Escalator.JsniUtil::moveScrollFromEvent(*)(esc, deltaX, deltaY, e);
             });
         }-*/;

client/src/main/java/com/vaadin/client/widgets/Grid.java

@@ -275,8 +275,8 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
              */
             public void setText(String text) {
                 detach();
-                this.content = text;
-                this.type = GridStaticCellType.TEXT;
+                content = text;
+                type = GridStaticCellType.TEXT;
                 section.requestSectionRefresh();
             }
 
@@ -355,8 +355,8 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
             public void setHtml(String html) {
                 detach();
 
-                this.content = html;
-                this.type = GridStaticCellType.HTML;
+                content = html;
+                type = GridStaticCellType.HTML;
                 section.requestSectionRefresh();
             }
 
@@ -388,13 +388,13 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
              *            null).
              */
             public void setWidget(Widget widget) {
-                if (this.content == widget) {
+                if (content == widget) {
                     return;
                 }
 
                 detach();
-                this.content = widget;
-                this.type = GridStaticCellType.WIDGET;
+                content = widget;
+                type = GridStaticCellType.WIDGET;
                 section.requestSectionRefresh();
             }
 
@@ -7937,9 +7937,9 @@ public class Grid<T> extends ResizeComposite implements HasSelectionHandlers<T>,
 
                         cell = new Cell(rowIndex, colIndex, cellElement);
                     } catch (IllegalStateException exception) {
-                        // IllegalStateException may occur if user has scrolled Grid so
-                        // that Escalator has updated, and row under Editor is no longer
-                        // there
+                        // IllegalStateException may occur if user has scrolled
+                        // Grid so that Escalator has updated, and row under
+                        // Editor is no longer there
                         return;
                     }
                 } else {

compatibility-server-gae/src/main/java/com/vaadin/server/GAEVaadinServlet.java

@@ -204,9 +204,8 @@ public class GAEVaadinServlet extends VaadinServlet {
         }
 
         boolean locked = false;
-        MemcacheService memcache = null;
         String mutex = MUTEX_BASE + session.getId();
-        memcache = MemcacheServiceFactory.getMemcacheService();
+        MemcacheService memcache = MemcacheServiceFactory.getMemcacheService();
         try {
             // try to get lock
             long started = System.currentTimeMillis();

compatibility-server/src/main/java/com/vaadin/v7/data/fieldgroup/DefaultFieldGroupFieldFactory.java

@@ -44,8 +44,9 @@ import com.vaadin.v7.ui.TextField;
  * instance.
  *
  * @author Vaadin Ltd
- * @deprecated As of 8.0, no direct replacement available. {@link Binder#forMemberField(HasValue)} and
- * {@link Binder#bindInstanceFields(Object)} should be used instead.
+ * @deprecated As of 8.0, no direct replacement available.
+ *             {@link Binder#forMemberField(HasValue)} and
+ *             {@link Binder#bindInstanceFields(Object)} should be used instead.
  */
 @Deprecated
 public class DefaultFieldGroupFieldFactory implements FieldGroupFieldFactory {
@@ -68,12 +69,13 @@ public class DefaultFieldGroupFieldFactory implements FieldGroupFieldFactory {
         return INSTANCE;
     }
 
+    @SuppressWarnings("rawtypes")
     @Override
     public <T extends Field> T createField(Class<?> type, Class<T> fieldType) {
         if (Enum.class.isAssignableFrom(type)) {
             return createEnumField(type, fieldType);
         } else if (Date.class.isAssignableFrom(type)) {
-            return createDateField(type, fieldType);
+            return createDateField(fieldType);
         } else if (Boolean.class.isAssignableFrom(type)
                 || boolean.class.isAssignableFrom(type)) {
             return createBooleanField(fieldType);
@@ -94,7 +96,8 @@ public class DefaultFieldGroupFieldFactory implements FieldGroupFieldFactory {
         return rta;
     }
 
-    private <T extends Field> T createEnumField(Class<?> type,
+    @SuppressWarnings({ "unchecked" })
+    private <T extends Field<?>> T createEnumField(Class<?> type,
             Class<T> fieldType) {
         // Determine first if we should (or can) create a select for the enum
         Class<AbstractSelect> selectClass = null;
@@ -106,7 +109,7 @@ public class DefaultFieldGroupFieldFactory implements FieldGroupFieldFactory {
 
         if (selectClass != null) {
             AbstractSelect s = createCompatibleSelect(selectClass);
-            populateWithEnumData(s, (Class<? extends Enum>) type);
+            populateWithEnumData(s, (Class<? extends Enum<?>>) type);
             return (T) s;
         } else if (AbstractTextField.class.isAssignableFrom(fieldType)) {
             return (T) createAbstractTextField(
@@ -116,9 +119,8 @@ public class DefaultFieldGroupFieldFactory implements FieldGroupFieldFactory {
         return null;
     }
 
-    @SuppressWarnings("unchecked")
-    private <T extends Field> T createDateField(Class<?> type,
-            Class<T> fieldType) {
+    @SuppressWarnings({ "unchecked" })
+    private <T extends Field<?>> T createDateField(Class<T> fieldType) {
         AbstractField<?> field;
 
         if (InlineDateField.class.isAssignableFrom(fieldType)) {
@@ -177,10 +179,12 @@ public class DefaultFieldGroupFieldFactory implements FieldGroupFieldFactory {
      *            the type of the field
      * @return true if any AbstractSelect can be assigned to the field
      */
+    @SuppressWarnings("rawtypes")
     protected boolean anySelect(Class<? extends Field> fieldType) {
         return anyField(fieldType) || fieldType == AbstractSelect.class;
     }
 
+    @SuppressWarnings({ "rawtypes", "unchecked" })
     protected <T extends Field> T createBooleanField(Class<T> fieldType) {
         if (fieldType.isAssignableFrom(CheckBox.class)) {
             CheckBox cb = new CheckBox(null);
@@ -194,6 +198,7 @@ public class DefaultFieldGroupFieldFactory implements FieldGroupFieldFactory {
         return null;
     }
 
+    @SuppressWarnings("unchecked")
     protected <T extends AbstractTextField> T createAbstractTextField(
             Class<T> fieldType) {
         if (fieldType == AbstractTextField.class) {
@@ -222,6 +227,7 @@ public class DefaultFieldGroupFieldFactory implements FieldGroupFieldFactory {
      * @return A field capable of editing the data or null if no field could be
      *         created
      */
+    @SuppressWarnings("rawtypes")
     protected <T extends Field> T createDefaultField(Class<?> type,
             Class<T> fieldType) {
         if (fieldType.isAssignableFrom(TextField.class)) {
@@ -239,6 +245,7 @@ public class DefaultFieldGroupFieldFactory implements FieldGroupFieldFactory {
      * @param enumClass
      *            The Enum class to use
      */
+    @SuppressWarnings({ "rawtypes", "unchecked" })
     protected void populateWithEnumData(AbstractSelect select,
             Class<? extends Enum> enumClass) {
         select.removeAllItems();
@@ -247,7 +254,6 @@ public class DefaultFieldGroupFieldFactory implements FieldGroupFieldFactory {
         }
         select.addContainerProperty(CAPTION_PROPERTY_ID, String.class, "");
         select.setItemCaptionPropertyId(CAPTION_PROPERTY_ID);
-        @SuppressWarnings("unchecked")
         EnumSet<?> enumSet = EnumSet.allOf(enumClass);
         for (Object r : enumSet) {
             Item newItem = select.addItem(r);

compatibility-server/src/main/java/com/vaadin/v7/server/communication/data/RpcDataProviderExtension.java

@@ -52,10 +52,10 @@ import elemental.json.JsonObject;
 
 /**
  * Provides Vaadin server-side container data source to a
- * {@link com.vaadin.v7.client.connectors.GridConnector GridConnector}. This is currently
- * implemented as an Extension hardcoded to support a specific connector type.
- * This will be changed once framework support for something more flexible has
- * been implemented.
+ * {@link com.vaadin.v7.client.connectors.GridConnector GridConnector}. This is
+ * currently implemented as an Extension hardcoded to support a specific
+ * connector type. This will be changed once framework support for something
+ * more flexible has been implemented.
  *
  * @since 7.4
  * @author Vaadin Ltd
@@ -152,10 +152,10 @@ public class RpcDataProviderExtension extends AbstractExtension {
 
     /**
      * A class to listen to changes in property values in the Container added
-     * with {@link Grid#setContainerDatasource(com.vaadin.v7.data.Container.Indexed)
-     * Grid#setContainerDatasource(Container.Indexed)},
-     * and notifies the data source to update the client-side representation
-     * of the modified item.
+     * with
+     * {@link Grid#setContainerDatasource(com.vaadin.v7.data.Container.Indexed)
+     * Grid#setContainerDatasource(Container.Indexed)}, and notifies the data
+     * source to update the client-side representation of the modified item.
      * <p>
      * One instance of this class can (and should) be reused for all the
      * properties in an item, since this class will inform that the entire row
@@ -166,8 +166,8 @@ public class RpcDataProviderExtension extends AbstractExtension {
      * value changes, an instance of this class needs to be attached to each and
      * every Item's Property in the container.
      *
-     * @see Grid#addValueChangeListener(com.vaadin.v7.data.Container, Object, Object)
-     *      Grid#addValueChangeListener(Container, Object, Object)
+     * @see Grid#addValueChangeListener(com.vaadin.v7.data.Container, Object,
+     *      Object) Grid#addValueChangeListener(Container, Object, Object)
      * @see Grid#valueChangeListeners
      */
     private class GridValueChangeListener implements ValueChangeListener {
@@ -389,15 +389,14 @@ public class RpcDataProviderExtension extends AbstractExtension {
 
             Item item = container.getItem(itemId);
 
-            rows.set(i, getRowData(getGrid().getColumns(), itemId, item));
+            rows.set(i, getRowData(itemId, item));
         }
         rpc.setRowData(firstRowToPush, rows);
 
         activeItemHandler.addActiveItems(itemIds);
     }
 
-    private JsonObject getRowData(Collection<Column> columns, Object itemId,
-            Item item) {
+    private JsonObject getRowData(Object itemId, Item item) {
 
         final JsonObject rowObject = Json.createObject();
         for (DataGenerator dg : dataGenerators) {
@@ -530,14 +529,13 @@ public class RpcDataProviderExtension extends AbstractExtension {
         }
 
         Collection<Object> activeItemIds = activeItemHandler.getActiveItemIds();
-        List<Column> columns = getGrid().getColumns();
         JsonArray rowData = Json.createArray();
         int i = 0;
         for (Object itemId : itemIds) {
             if (activeItemIds.contains(itemId)) {
                 Item item = container.getItem(itemId);
                 if (item != null) {
-                    JsonObject row = getRowData(columns, itemId, item);
+                    JsonObject row = getRowData(itemId, item);
                     rowData.set(i++, row);
                 }
             }

compatibility-server/src/main/java/com/vaadin/v7/ui/ComboBox.java

@@ -464,8 +464,7 @@ public class ComboBox extends AbstractSelect
             assert filteredSize >= 0;
             currentPage = adjustCurrentPage(currentPage, needNullSelectOption,
                     indexToEnsureInView, filteredSize);
-            int first = getFirstItemIndexOnCurrentPage(needNullSelectOption,
-                    filteredSize);
+            int first = getFirstItemIndexOnCurrentPage(needNullSelectOption);
             int last = getLastItemIndexOnCurrentPage(needNullSelectOption,
                     filteredSize, first);
 
@@ -562,8 +561,7 @@ public class ComboBox extends AbstractSelect
             int size = options.size();
             currentPage = adjustCurrentPage(currentPage, needNullSelectOption,
                     indexToEnsureInView, size);
-            int first = getFirstItemIndexOnCurrentPage(needNullSelectOption,
-                    size);
+            int first = getFirstItemIndexOnCurrentPage(needNullSelectOption);
             int last = getLastItemIndexOnCurrentPage(needNullSelectOption, size,
                     first);
             return options.subList(first, last + 1);
@@ -581,14 +579,10 @@ public class ComboBox extends AbstractSelect
      *            true if a null option should be shown before any other options
      *            (takes up the first slot on the first page, not counted in
      *            index)
-     * @param size
-     *            number of items after filtering (not including the null item,
-     *            if any)
      * @return first item to show on the UI (index to the filtered list of
      *         options, not taking the null item into consideration if any)
      */
-    private int getFirstItemIndexOnCurrentPage(boolean needNullSelectOption,
-            int size) {
+    private int getFirstItemIndexOnCurrentPage(boolean needNullSelectOption) {
         // Not all options are visible, find out which ones are on the
         // current "page".
         int first = currentPage * pageLength;

compatibility-server/src/main/java/com/vaadin/v7/ui/Grid.java

@@ -212,7 +212,8 @@ public class Grid extends AbstractComponent
      * @since 7.5.0
      */
     @Deprecated
-    public interface ColumnVisibilityChangeListener extends SerializableEventListener {
+    public interface ColumnVisibilityChangeListener
+            extends SerializableEventListener {
         /**
          * Called when a column has become hidden or unhidden.
          *
@@ -567,6 +568,7 @@ public class Grid extends AbstractComponent
             }
         }
 
+        @SuppressWarnings("rawtypes")
         @Override
         protected <T extends Field> T build(String caption, Class<?> dataType,
                 Class<T> fieldType) throws BindException {
@@ -630,6 +632,7 @@ public class Grid extends AbstractComponent
             return INSTANCE;
         }
 
+        @SuppressWarnings("rawtypes")
         @Override
         public <T extends Field> T createField(Class<?> type,
                 Class<T> fieldType) {
@@ -649,6 +652,7 @@ public class Grid extends AbstractComponent
             return super.createCompatibleSelect(fieldType);
         }
 
+        @SuppressWarnings("rawtypes")
         @Override
         protected void populateWithEnumData(AbstractSelect select,
                 Class<? extends Enum> enumClass) {
@@ -2364,7 +2368,8 @@ public class Grid extends AbstractComponent
             Renderer<?> renderer = column.getRenderer();
 
             Item item = cell.getItem();
-            Property itemProperty = item.getItemProperty(cell.getPropertyId());
+            Property<?> itemProperty = item
+                    .getItemProperty(cell.getPropertyId());
             Object modelValue = itemProperty == null ? null
                     : itemProperty.getValue();
 
@@ -2505,6 +2510,7 @@ public class Grid extends AbstractComponent
              *            The cells to merge. Must be from the same row.
              * @return The remaining visible cell after the merge
              */
+            @SuppressWarnings("unchecked")
             public CELLTYPE join(CELLTYPE... cells) {
                 if (cells.length < 2) {
                     throw new IllegalArgumentException(
@@ -3776,6 +3782,7 @@ public class Grid extends AbstractComponent
             return converter;
         }
 
+        @SuppressWarnings("unchecked")
         private <T> boolean internalSetRenderer(Renderer<T> renderer) {
 
             Converter<? extends T, ?> converter;
@@ -4410,6 +4417,7 @@ public class Grid extends AbstractComponent
          *            the locale to use in conversion
          * @return an encoded value ready to be sent to the client
          */
+        @SuppressWarnings("unchecked")
         public static <T> JsonValue encodeValue(Object modelValue,
                 Renderer<T> renderer, Converter<?, ?> converter,
                 Locale locale) {
@@ -4437,7 +4445,6 @@ public class Grid extends AbstractComponent
             } else {
                 assert presentationType
                         .isAssignableFrom(converter.getPresentationType());
-                @SuppressWarnings("unchecked")
                 Converter<T, Object> safeConverter = (Converter<T, Object>) converter;
                 presentationValue = safeConverter.convertToPresentation(
                         modelValue, safeConverter.getPresentationType(),
@@ -4688,13 +4695,6 @@ public class Grid extends AbstractComponent
      */
     private SelectionModel selectionModel;
 
-    /**
-     * Used to know whether selection change events originate from the server or
-     * the client so the selection change handler knows whether the changes
-     * should be sent to the client.
-     */
-    private boolean applyingSelectionFromClient;
-
     private final Header header = new Header(this);
     private final Footer footer = new Footer(this);
 
@@ -6739,7 +6739,8 @@ public class Grid extends AbstractComponent
      * @since 7.6
      */
 
-    public void setCellDescriptionGenerator(CellDescriptionGenerator generator) {
+    public void setCellDescriptionGenerator(
+            CellDescriptionGenerator generator) {
         setCellDescriptionGenerator(generator, ContentMode.PREFORMATTED);
     }
 
@@ -6760,12 +6761,13 @@ public class Grid extends AbstractComponent
      * @since 8.3.2
      */
     public void setCellDescriptionGenerator(CellDescriptionGenerator generator,
-                                            ContentMode contentMode) {
+            ContentMode contentMode) {
         if (contentMode == null) {
             throw new IllegalArgumentException("Content mode cannot be null");
         }
         cellDescriptionGenerator = generator;
-        getState().hasDescriptions = (generator != null || rowDescriptionGenerator != null);
+        getState().hasDescriptions = (generator != null
+                || rowDescriptionGenerator != null);
         getState().cellTooltipContentMode = contentMode;
         datasourceExtension.refreshCache();
     }
@@ -6811,7 +6813,7 @@ public class Grid extends AbstractComponent
      * @since 7.6
      */
     public void setRowDescriptionGenerator(RowDescriptionGenerator generator) {
-        setRowDescriptionGenerator(generator, ContentMode.PREFORMATTED );
+        setRowDescriptionGenerator(generator, ContentMode.PREFORMATTED);
     }
 
     /**
@@ -6832,7 +6834,7 @@ public class Grid extends AbstractComponent
      * @since 8.3.2
      */
     public void setRowDescriptionGenerator(RowDescriptionGenerator generator,
-                                           ContentMode contentMode) {
+            ContentMode contentMode) {
         if (contentMode == null) {
             throw new IllegalArgumentException("Content mode cannot be null");
         }
@@ -6934,6 +6936,7 @@ public class Grid extends AbstractComponent
      * @throws UnsupportedOperationException
      *             if the container does not support adding new items
      */
+    @SuppressWarnings("unchecked")
     public Object addRow(Object... values) {
         if (values == null) {
             throw new IllegalArgumentException("Values cannot be null");

compatibility-server/src/main/java/com/vaadin/v7/ui/Tree.java

@@ -211,6 +211,7 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
      * Creates a new empty tree with caption.
      *
      * @param caption
+     *            the caption of the component
      */
     public Tree(String caption) {
         this(caption, new HierarchicalContainer());
@@ -220,7 +221,9 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
      * Creates a new tree with caption and connect it to a Container.
      *
      * @param caption
+     *            the caption of the component
      * @param dataSource
+     *            the container
      */
     public Tree(String caption, Container dataSource) {
         super(caption, dataSource);
@@ -370,6 +373,7 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
      * succeeds only if all expandable items are expanded.
      *
      * @param startItemId
+     *            ID of the initial item
      * @return True if the expand operation succeeded
      */
     public boolean expandItemsRecursively(Object startItemId) {
@@ -423,6 +427,7 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
      * succeeds only if all expandable items are collapsed.
      *
      * @param startItemId
+     *            ID of the initial item
      * @return True if the collapse operation succeeded
      */
     public boolean collapseItemsRecursively(Object startItemId) {
@@ -670,8 +675,6 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
         // rendered selectedKeys
         LinkedList<String> selectedKeys = new LinkedList<String>();
 
-        final LinkedList<String> expandedKeys = new LinkedList<String>();
-
         // Iterates through hierarchical tree using a stack of iterators
         final Stack<Iterator<?>> iteratorStack = new Stack<Iterator<?>>();
         Collection<?> ids;
@@ -769,7 +772,6 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
                 }
                 if (areChildrenAllowed(itemId) && isExpanded(itemId)) {
                     target.addAttribute("expanded", true);
-                    expandedKeys.add(key);
                 }
 
                 // Add caption change listener
@@ -1027,11 +1029,12 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
         private final Object expandedItemId;
 
         /**
-         * New instance of options change event.
+         * New instance of expanding event.
          *
          * @param source
-         *            the Source of the event.
+         *            the source component of the event.
          * @param expandedItemId
+         *            ID of the item that was expanded
          */
         public ExpandEvent(Component source, Object expandedItemId) {
             super(source);
@@ -1039,9 +1042,9 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
         }
 
         /**
-         * Node where the event occurred.
+         * ID of the item that was expanded.
          *
-         * @return the Source of the event.
+         * @return the item id.
          */
         public Object getItemId() {
             return expandedItemId;
@@ -1082,6 +1085,9 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
     /**
      * @deprecated As of 7.0, replaced by
      *             {@link #addExpandListener(ExpandListener)}
+     *
+     * @param listener
+     *            the Listener to be added.
      */
     @Deprecated
     public void addListener(ExpandListener listener) {
@@ -1102,6 +1108,9 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
     /**
      * @deprecated As of 7.0, replaced by
      *             {@link #removeExpandListener(ExpandListener)}
+     *
+     * @param listener
+     *            the Listener to be removed.
      */
     @Deprecated
     public void removeListener(ExpandListener listener) {
@@ -1137,6 +1146,7 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
          * @param source
          *            the Source of the event.
          * @param collapsedItemId
+         *            ID of the item that was collapsed
          */
         public CollapseEvent(Component source, Object collapsedItemId) {
             super(source);
@@ -1144,7 +1154,7 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
         }
 
         /**
-         * Gets tge Collapsed Item id.
+         * Gets the ID of the item that was collapsed.
          *
          * @return the collapsed item id.
          */
@@ -1188,6 +1198,9 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
     /**
      * @deprecated As of 7.0, replaced by
      *             {@link #addCollapseListener(CollapseListener)}
+     *
+     * @param listener
+     *            the Listener to be added.
      */
     @Deprecated
     public void addListener(CollapseListener listener) {
@@ -1208,6 +1221,9 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
     /**
      * @deprecated As of 7.0, replaced by
      *             {@link #removeCollapseListener(CollapseListener)}
+     *
+     * @param listener
+     *            the Listener to be removed.
      */
     @Deprecated
     public void removeListener(CollapseListener listener) {
@@ -1476,9 +1492,11 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
          * If the method returns null, the current target is on a root node or
          * on other undefined area over the tree component.
          * <p>
-         * The default Tree implementation marks the targetted tree node with
-         * CSS classnames v-tree-node-dragfolder and
-         * v-tree-node-caption-dragfolder (for the caption element).
+         * The default Tree implementation marks the targeted tree node with CSS
+         * classnames v-tree-node-dragfolder and v-tree-node-caption-dragfolder
+         * (for the caption element).
+         *
+         * @return the ID of the item that can receive the targeted drop
          */
         public Object getItemIdInto() {
 
@@ -1553,10 +1571,11 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
     }
 
     /**
-     * Sets the drag mode that controls how Tree behaves as a {@link DragSource}
-     * .
+     * Sets the drag mode that controls how Tree behaves as a
+     * {@link DragSource}.
      *
      * @param dragMode
+     *            the drag mode to set
      */
     public void setDragMode(TreeDragMode dragMode) {
         this.dragMode = dragMode;
@@ -1831,6 +1850,8 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
     /**
      * Get the item description generator which generates tooltips for tree
      * items.
+     *
+     * @return the item description generator
      */
     public ItemDescriptionGenerator getItemDescriptionGenerator() {
         return itemDescriptionGenerator;

compatibility-server/src/main/java/com/vaadin/v7/ui/components/calendar/CalendarDateRange.java

@@ -36,8 +36,6 @@ public class CalendarDateRange implements Serializable {
 
     private Date end;
 
-    private final transient TimeZone tz;
-
     /**
      * Constructor.
      *
@@ -45,12 +43,13 @@ public class CalendarDateRange implements Serializable {
      *            The start date and time of the date range
      * @param end
      *            The end date and time of the date range
+     * @param tz
+     *            Time zone. Unused.
      */
     public CalendarDateRange(Date start, Date end, TimeZone tz) {
         super();
         this.start = start;
         this.end = end;
-        this.tz = tz;
     }
 
     /**

compatibility-server/src/main/java/com/vaadin/v7/ui/components/colorpicker/ColorPickerPopup.java

@@ -16,7 +16,6 @@
 package com.vaadin.v7.ui.components.colorpicker;
 
 import java.lang.reflect.Method;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
@@ -161,6 +160,9 @@ public class ColorPickerPopup extends Window
 
     /**
      * Instantiates a new color picker popup.
+     *
+     * @param initialColor
+     *            initially selected color
      */
     public ColorPickerPopup(Color initialColor) {
         this();
@@ -209,11 +211,6 @@ public class ColorPickerPopup extends Window
         history.setWidth("97%");
         history.setHeight("22px");
 
-        // Create the default colors
-        List<Color> defaultColors = new ArrayList<Color>();
-        defaultColors.add(Color.BLACK);
-        defaultColors.add(Color.WHITE);
-
         // Create the history
         VerticalLayout innerContainer = new VerticalLayout();
         innerContainer.setWidth("100%");

server/src/main/java/com/vaadin/server/DragAndDropService.java

@@ -133,8 +133,7 @@ public class DragAndDropService implements VariableOwner, ClientConnector {
          * operation based on the info passed from the client widgets (drag
          * source for Transferable, drop target for DragDropDetails).
          */
-        Transferable transferable = constructTransferable(dropTarget,
-                variables);
+        Transferable transferable = constructTransferable(variables);
         TargetDetails dropData = constructDragDropDetails(dropTarget,
                 variables);
         DragAndDropEvent dropEvent = new DragAndDropEvent(transferable,
@@ -161,8 +160,7 @@ public class DragAndDropService implements VariableOwner, ClientConnector {
          * operation based on the info passed from the client widgets (drag
          * source for Transferable, current target for DragDropDetails).
          */
-        Transferable transferable = constructTransferable(dropTarget,
-                variables);
+        Transferable transferable = constructTransferable(variables);
         TargetDetails dragDropDetails = constructDragDropDetails(dropTarget,
                 variables);
 
@@ -207,8 +205,7 @@ public class DragAndDropService implements VariableOwner, ClientConnector {
     }
 
     @SuppressWarnings("unchecked")
-    private Transferable constructTransferable(DropTarget dropHandlerOwner,
-            Map<String, Object> variables) {
+    private Transferable constructTransferable(Map<String, Object> variables) {
         final Component sourceComponent = (Component) variables
                 .get("component");
 

server/src/main/java/com/vaadin/server/JsonCodec.java

@@ -412,7 +412,7 @@ public class JsonCodec implements Serializable {
         // Arrays
         if (JsonConstants.VTYPE_ARRAY.equals(transportType)) {
 
-            return decodeObjectArray(targetType, (JsonArray) encodedJsonValue,
+            return decodeObjectArray((JsonArray) encodedJsonValue,
                     connectorTracker);
 
         } else if (JsonConstants.VTYPE_STRINGARRAY.equals(transportType)) {
@@ -625,13 +625,14 @@ public class JsonCodec implements Serializable {
         }
     }
 
+    @SuppressWarnings({ "rawtypes", "unchecked" })
     private static Object decodeEnum(Class<? extends Enum> cls,
             JsonString value) {
         return Enum.valueOf(cls, value.getString());
     }
 
-    private static Object[] decodeObjectArray(Type targetType,
-            JsonArray jsonArray, ConnectorTracker connectorTracker) {
+    private static Object[] decodeObjectArray(JsonArray jsonArray,
+            ConnectorTracker connectorTracker) {
         List<Object> list = decodeList(List.class, true, jsonArray,
                 connectorTracker);
         return list.toArray(new Object[list.size()]);
@@ -685,6 +686,7 @@ public class JsonCodec implements Serializable {
         }
     }
 
+    @SuppressWarnings("deprecation")
     public static EncodeResult encode(Object value, JsonValue diffState,
             Type valueType, ConnectorTracker connectorTracker) {
 
@@ -1000,6 +1002,7 @@ public class JsonCodec implements Serializable {
     /*
      * Encodes a connector map. Invisible connectors are skipped.
      */
+    @SuppressWarnings("deprecation")
     private static JsonObject encodeConnectorMap(Type valueType, Map<?, ?> map,
             ConnectorTracker connectorTracker) {
         JsonObject jsonMap = Json.createObject();
@@ -1040,6 +1043,7 @@ public class JsonCodec implements Serializable {
         return TYPE_TO_TRANSPORT_TYPE.get(getClassForType(valueType));
     }
 
+    @SuppressWarnings({ "rawtypes", "unchecked" })
     private static JsonValue serializeJson(Object value,
             ConnectorTracker connectorTracker) {
         JSONSerializer serializer = CUSTOM_SERIALIZERS.get(value.getClass());

server/src/main/java/com/vaadin/server/JsonPaintTarget.java

@@ -45,7 +45,7 @@ import com.vaadin.ui.CustomLayout;
  * @author Vaadin Ltd.
  * @since 5.0
  */
-@SuppressWarnings("serial")
+@SuppressWarnings({ "deprecation", "serial" })
 public class JsonPaintTarget implements PaintTarget {
 
     /* Document type declarations */
@@ -82,6 +82,7 @@ public class JsonPaintTarget implements PaintTarget {
      * Creates a new JsonPaintTarget.
      *
      * @param manager
+     *            communication manager
      * @param outWriter
      *            A character-output stream.
      * @param cachingRequired
@@ -124,6 +125,8 @@ public class JsonPaintTarget implements PaintTarget {
      *
      * @param tagName
      *            the name of the start tag.
+     * @param isChildNode
+     *            {@code true} if child node, {@code false} otherwise
      * @throws PaintException
      *             if the paint operation failed.
      *
@@ -181,9 +184,7 @@ public class JsonPaintTarget implements PaintTarget {
         if (!openJsonTags.isEmpty()) {
             final JsonTag parent = openJsonTags.pop();
 
-            String lastTag = "";
-
-            lastTag = mOpenTags.pop();
+            String lastTag = mOpenTags.pop();
             if (!tagName.equalsIgnoreCase(lastTag)) {
                 throw new PaintException("Invalid UIDL: wrong ending tag: '"
                         + tagName + "' expected: '" + lastTag + "'.");

server/src/main/java/com/vaadin/server/VaadinServlet.java

@@ -78,7 +78,7 @@ import elemental.json.Json;
 import elemental.json.JsonArray;
 import elemental.json.JsonObject;
 
-@SuppressWarnings("serial")
+@SuppressWarnings({ "deprecation", "serial" })
 public class VaadinServlet extends HttpServlet implements Constants {
 
     private class ScssCacheEntry implements Serializable {
@@ -197,9 +197,13 @@ public class VaadinServlet extends HttpServlet implements Constants {
 
     private VaadinServletService servletService;
 
-    // Mapped uri is for the jar file
-    static final Map<URI, Integer> openFileSystems = new HashMap<>();
-    private static final Object fileSystemLock = new Object();
+    /**
+     * Mapped uri is for the jar file.
+     * <p>
+     * FOR INTERNAL USE ONLY, may get renamed or removed.
+     */
+    static final Map<URI, Integer> OPEN_FILE_SYSTEMS = new HashMap<>();
+    private static final Object FILE_SYSTEM_LOCK = new Object();
 
     /**
      * Called by the servlet container to indicate to a servlet that the servlet
@@ -696,6 +700,7 @@ public class VaadinServlet extends HttpServlet implements Constants {
      * servers).
      *
      * @param servletContext
+     *            the {@link ServletContext} in which this servlet is running
      * @param path
      *            the resource path.
      * @return the resource path.
@@ -706,8 +711,7 @@ public class VaadinServlet extends HttpServlet implements Constants {
     @Deprecated
     protected static String getResourcePath(ServletContext servletContext,
             String path) {
-        String resultPath = null;
-        resultPath = servletContext.getRealPath(path);
+        String resultPath = servletContext.getRealPath(path);
         if (resultPath != null) {
             return resultPath;
         } else {
@@ -729,7 +733,8 @@ public class VaadinServlet extends HttpServlet implements Constants {
      * e.g. '(' and ')', so values should be safe in javascript too.
      *
      * @param themeName
-     * @return
+     *            name of the theme
+     * @return name of the theme without special characters
      *
      * @deprecated As of 7.0. Will likely change or be removed in a future
      *             version
@@ -782,7 +787,7 @@ public class VaadinServlet extends HttpServlet implements Constants {
     /**
      * Returns the default theme. Must never return null.
      *
-     * @return
+     * @return default theme name
      */
     public static String getDefaultTheme() {
         return DEFAULT_THEME_NAME;
@@ -825,7 +830,9 @@ public class VaadinServlet extends HttpServlet implements Constants {
      * @param response
      *            The response
      * @throws IOException
+     *             if an I/O exception occurs
      * @throws ServletException
+     *             if a servlet exception occurs
      *
      * @since 8.5
      */
@@ -971,6 +978,7 @@ public class VaadinServlet extends HttpServlet implements Constants {
      * @param resourceUrl
      *            The url to send
      * @throws IOException
+     *             if an I/O exception occurs
      */
     protected void writeStaticResourceResponse(HttpServletRequest request,
             HttpServletResponse response, URL resourceUrl) throws IOException {
@@ -1228,8 +1236,11 @@ public class VaadinServlet extends HttpServlet implements Constants {
      * outside the VAADIN directory if the method is overridden.
      *
      * @param request
+     *            current request
      * @param resourceUrl
-     * @return
+     *            URL of the resource to validate
+     * @return {@code true} if the resource is a valid VAADIN resource,
+     *         {@code false} otherwise
      *
      * @since 6.6.7
      *
@@ -1356,7 +1367,7 @@ public class VaadinServlet extends HttpServlet implements Constants {
 
     // Package protected for feature verification purpose
     FileSystem getFileSystem(URI resourceURI) throws IOException {
-        synchronized (fileSystemLock) {
+        synchronized (FILE_SYSTEM_LOCK) {
             URI fileURI = getFileURI(resourceURI);
             if (!fileURI.getScheme().equals("file")) {
                 throw new IOException("Can not read scheme '"
@@ -1364,7 +1375,7 @@ public class VaadinServlet extends HttpServlet implements Constants {
                         + " and will determine this as not a folder");
             }
 
-            Integer locks = openFileSystems.computeIfPresent(fileURI,
+            Integer locks = OPEN_FILE_SYSTEMS.computeIfPresent(fileURI,
                     (key, value) -> value + 1);
             if (locks != null) {
                 // Get filesystem is for the file to get the correct provider
@@ -1373,20 +1384,20 @@ public class VaadinServlet extends HttpServlet implements Constants {
             // Opened filesystem is for the file to get the correct provider
             FileSystem fileSystem = FileSystems.newFileSystem(resourceURI,
                     Collections.emptyMap());
-            openFileSystems.put(fileURI, 1);
+            OPEN_FILE_SYSTEMS.put(fileURI, 1);
             return fileSystem;
         }
     }
 
     // Package protected for feature verification purpose
     void closeFileSystem(URI resourceURI) {
-        synchronized (fileSystemLock) {
+        synchronized (FILE_SYSTEM_LOCK) {
             try {
                 URI fileURI = getFileURI(resourceURI);
-                Integer locks = openFileSystems.computeIfPresent(fileURI,
+                Integer locks = OPEN_FILE_SYSTEMS.computeIfPresent(fileURI,
                         (key, value) -> value - 1);
                 if (locks != null && locks == 0) {
-                    openFileSystems.remove(fileURI);
+                    OPEN_FILE_SYSTEMS.remove(fileURI);
                     // Get filesystem is for the file to get the correct
                     // provider
                     FileSystems.getFileSystem(resourceURI).close();
@@ -1459,7 +1470,8 @@ public class VaadinServlet extends HttpServlet implements Constants {
 
     /**
      * @param request
-     * @return
+     *            the request that is to be evaluated
+     * @return request type
      *
      * @deprecated As of 7.0. This is no longer used and only provided for
      *             backwards compatibility. Each {@link RequestHandler} can
@@ -1574,6 +1586,7 @@ public class VaadinServlet extends HttpServlet implements Constants {
      *
      * @param request
      *            the HTTP request.
+     * @return current application URL
      * @throws MalformedURLException
      *             if the application is denied access to the persistent data
      *             store represented by the given URL.
@@ -1687,6 +1700,7 @@ public class VaadinServlet extends HttpServlet implements Constants {
      * characters" to keep the text somewhat readable.
      *
      * @param unsafe
+     *            the string that needs to be made safe
      * @return a safe string to be added inside an html tag
      *
      * @deprecated As of 7.0. Will likely change or be removed in a future
@@ -1714,10 +1728,9 @@ public class VaadinServlet extends HttpServlet implements Constants {
 
     private static boolean isSafe(char c) {
         return //
-        c > 47 && c < 58 || // alphanum
-                c > 64 && c < 91 || // A-Z
-                c > 96 && c < 123 // a-z
-        ;
+        (c > 47 && c < 58) || // alphanum
+                (c > 64 && c < 91) || // A-Z
+                (c > 96 && c < 123); // a-z
     }
 
     private static final Logger getLogger() {

server/src/main/java/com/vaadin/server/communication/ResourceWriter.java

@@ -26,7 +26,6 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 
 import com.vaadin.server.JsonPaintTarget;
-import com.vaadin.server.LegacyCommunicationManager;
 import com.vaadin.ui.CustomLayout;
 import com.vaadin.ui.UI;
 
@@ -53,10 +52,6 @@ public class ResourceWriter implements Serializable {
     public void write(UI ui, Writer writer, JsonPaintTarget target)
             throws IOException {
 
-        // TODO PUSH Refactor so that this is not needed
-        LegacyCommunicationManager manager = ui.getSession()
-                .getCommunicationManager();
-
         // Precache custom layouts
 
         // TODO We should only precache the layouts that are not

server/src/main/java/com/vaadin/server/communication/ServerRpcHandler.java

@@ -31,7 +31,6 @@ import java.util.logging.Logger;
 import com.vaadin.server.ClientConnector;
 import com.vaadin.server.Constants;
 import com.vaadin.server.JsonCodec;
-import com.vaadin.server.LegacyCommunicationManager;
 import com.vaadin.server.LegacyCommunicationManager.InvalidUIDLSecurityKeyException;
 import com.vaadin.server.ServerRpcManager;
 import com.vaadin.server.ServerRpcManager.RpcInvocationException;
@@ -64,6 +63,7 @@ import elemental.json.impl.JsonUtil;
  * @author Vaadin Ltd
  * @since 7.1
  */
+@SuppressWarnings("deprecation")
 public class ServerRpcHandler implements Serializable {
 
     /**
@@ -212,6 +212,7 @@ public class ServerRpcHandler implements Serializable {
      * @param reader
      *            The {@link Reader} used to read the JSON.
      * @param request
+     *            The {@link VaadinRequest} to handle.
      * @throws IOException
      *             If reading the message fails.
      * @throws InvalidUIDLSecurityKeyException
@@ -332,8 +333,7 @@ public class ServerRpcHandler implements Serializable {
             Set<Connector> enabledConnectors = new HashSet<>();
 
             List<MethodInvocation> invocations = parseInvocations(
-                    ui.getConnectorTracker(), invocationsData,
-                    lastSyncIdSeenByClient);
+                    ui.getConnectorTracker(), invocationsData);
             for (MethodInvocation invocation : invocations) {
                 final ClientConnector connector = connectorTracker
                         .getConnector(invocation.getConnectorId());
@@ -489,14 +489,10 @@ public class ServerRpcHandler implements Serializable {
      * @param invocationsJson
      *            JSON containing all information needed to execute all
      *            requested RPC calls.
-     * @param lastSyncIdSeenByClient
-     *            the most recent sync id the client has seen at the time the
-     *            request was sent
      * @return list of MethodInvocation to perform
      */
     private List<MethodInvocation> parseInvocations(
-            ConnectorTracker connectorTracker, JsonArray invocationsJson,
-            int lastSyncIdSeenByClient) {
+            ConnectorTracker connectorTracker, JsonArray invocationsJson) {
         int invocationCount = invocationsJson.length();
         List<MethodInvocation> invocations = new ArrayList<>(invocationCount);
 
@@ -507,8 +503,7 @@ public class ServerRpcHandler implements Serializable {
             JsonArray invocationJson = invocationsJson.getArray(i);
 
             MethodInvocation invocation = parseInvocation(invocationJson,
-                    previousInvocation, connectorTracker,
-                    lastSyncIdSeenByClient);
+                    previousInvocation, connectorTracker);
             if (invocation != null) {
                 // Can be null if the invocation was a legacy invocation and it
                 // was merged with the previous one or if the invocation was
@@ -522,7 +517,7 @@ public class ServerRpcHandler implements Serializable {
 
     private MethodInvocation parseInvocation(JsonArray invocationJson,
             MethodInvocation previousInvocation,
-            ConnectorTracker connectorTracker, long lastSyncIdSeenByClient) {
+            ConnectorTracker connectorTracker) {
         String connectorId = invocationJson.getString(0);
         String interfaceName = invocationJson.getString(1);
         String methodName = invocationJson.getString(2);
@@ -536,7 +531,6 @@ public class ServerRpcHandler implements Serializable {
             }
 
             return parseLegacyChangeVariablesInvocation(connectorId,
-                    interfaceName, methodName,
                     (LegacyChangeVariablesInvocation) previousInvocation,
                     parametersJson, connectorTracker);
         } else {
@@ -547,7 +541,7 @@ public class ServerRpcHandler implements Serializable {
     }
 
     private LegacyChangeVariablesInvocation parseLegacyChangeVariablesInvocation(
-            String connectorId, String interfaceName, String methodName,
+            String connectorId,
             LegacyChangeVariablesInvocation previousInvocation,
             JsonArray parametersJson, ConnectorTracker connectorTracker) {
         if (parametersJson.length() != 2) {
@@ -643,10 +637,12 @@ public class ServerRpcHandler implements Serializable {
     }
 
     /**
-     * Generates an error message when the client is trying to to something
+     * Generates an error message when the client is trying to do something
      * ('what') with a connector which is disabled or invisible.
      *
      * @since 7.1.8
+     * @param what
+     *            the ignored operation
      * @param connector
      *            the connector which is disabled (or invisible)
      * @return an error message

server/src/main/java/com/vaadin/server/communication/UidlRequestHandler.java

@@ -46,6 +46,7 @@ import elemental.json.JsonException;
  * @author Vaadin Ltd
  * @since 7.1
  */
+@SuppressWarnings("deprecation")
 public class UidlRequestHandler extends SynchronizedRequestHandler
         implements SessionExpiredHandler {
 
@@ -89,7 +90,7 @@ public class UidlRequestHandler extends SynchronizedRequestHandler
         try {
             rpcHandler.handleRpc(uI, request.getReader(), request);
 
-            writeUidl(request, response, uI, stringWriter);
+            writeUidl(response, uI, stringWriter);
         } catch (JsonException e) {
             getLogger().log(Level.SEVERE, "Error writing JSON to response", e);
             // Refresh on client side
@@ -117,8 +118,8 @@ public class UidlRequestHandler extends SynchronizedRequestHandler
         UIInitHandler.commitJsonResponse(request, response, json);
     }
 
-    private void writeUidl(VaadinRequest request, VaadinResponse response,
-            UI ui, Writer writer) throws IOException {
+    private void writeUidl(VaadinResponse response, UI ui, Writer writer)
+            throws IOException {
         openJsonMessage(writer, response);
 
         new UidlWriter().write(ui, writer, false);

server/src/main/java/com/vaadin/server/widgetsetutils/ClassPathExplorer.java

@@ -52,8 +52,6 @@ import java.util.jar.Manifest;
  */
 public class ClassPathExplorer {
 
-    private static final String VAADIN_ADDON_VERSION_ATTRIBUTE = "Vaadin-Package-Version";
-
     /**
      * File filter that only accepts directories.
      */

server/src/main/java/com/vaadin/ui/AbstractDateField.java

@@ -427,7 +427,7 @@ public abstract class AbstractDateField<T extends Temporal & TemporalAdjuster &
     }
 
     /**
-     * Parses string representaion of date range limit into date type
+     * Parses string representation of date range limit into date type.
      *
      * @param temporalStr
      *            the string representation
@@ -1005,7 +1005,7 @@ public abstract class AbstractDateField<T extends Temporal & TemporalAdjuster &
                         .orElse(null));
     }
 
-    private Iterable<R> getResolutionsHigherOrEqualTo(R resoution) {
+    private Iterable<R> getResolutionsHigherOrEqualTo(R resolution) {
         return getResolutions().skip(resolution.ordinal())
                 .collect(Collectors.toList());
     }
@@ -1141,10 +1141,11 @@ public abstract class AbstractDateField<T extends Temporal & TemporalAdjuster &
     }
 
     /**
-     * Control whether value change event is emitted when user input value 
-     * does not meet the integrated range validator.
+     * Control whether value change event is emitted when user input value does
+     * not meet the integrated range validator.
      *
-     * @param preventInvalidInput Set to false to disable the value change event.
+     * @param preventInvalidInput
+     *            Set to false to disable the value change event.
      *
      * @since 8.13
      */
@@ -1153,8 +1154,8 @@ public abstract class AbstractDateField<T extends Temporal & TemporalAdjuster &
     }
 
     /**
-     * Check whether value change is emitted when user input value does
-     * not meet integrated range validator. The default is false.
+     * Check whether value change is emitted when user input value does not meet
+     * integrated range validator. The default is false.
      *
      * @return a Boolean value
      *

server/src/main/java/com/vaadin/ui/Grid.java

@@ -275,7 +275,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          *            <code>true</code> if event is a result of user
          *            interaction, <code>false</code> if from API call
          */
-        public ColumnReorderEvent(Grid source, boolean userOriginated) {
+        public ColumnReorderEvent(Grid<?> source, boolean userOriginated) {
             super(source);
             this.userOriginated = userOriginated;
         }
@@ -306,6 +306,8 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          *
          * @param source
          *            the grid where the event originated from
+         * @param column
+         *            the column that was resized
          * @param userOriginated
          *            <code>true</code> if event is a result of user
          *            interaction, <code>false</code> if from API call
@@ -356,6 +358,16 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          * Creates a new {@code ItemClick} event containing the given item and
          * Column originating from the given Grid.
          *
+         * @param source
+         *            the grid where the event originated from
+         * @param column
+         *            the column that contains the clicked cell
+         * @param item
+         *            the item that was clicked
+         * @param mouseEventDetails
+         *            mouse event details about the click
+         * @param rowIndex
+         *            the index of the row that contains the clicked cell
          */
         public ItemClick(Grid<T> source, Column<T, ?> column, T item,
                 MouseEventDetails mouseEventDetails, int rowIndex) {
@@ -390,6 +402,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          * @return the grid
          */
         @Override
+        @SuppressWarnings("unchecked")
         public Grid<T> getSource() {
             return (Grid<T>) super.getSource();
         }
@@ -501,6 +514,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
         }
 
         @Override
+        @SuppressWarnings("unchecked")
         public Grid<T> getComponent() {
             return (Grid<T>) super.getComponent();
         }
@@ -849,18 +863,18 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
     public static class Column<T, V> extends AbstractExtension {
 
         /**
-         * behavior when parsing nested properties which may contain
-         * <code>null</code> values in the property chain
+         * Behavior when parsing nested properties which may contain
+         * <code>null</code> values in the property chain.
          */
         public enum NestedNullBehavior {
             /**
-             * throw a NullPointerException if there is a nested
-             * <code>null</code> value
+             * Throw a NullPointerException if there is a nested
+             * <code>null</code> value.
              */
             THROW,
             /**
-             * silently ignore any exceptions caused by nested <code>null</code>
-             * values
+             * Silently ignore any exceptions caused by nested <code>null</code>
+             * values.
              */
             ALLOW_NULLS
         }
@@ -1578,6 +1592,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          *            the expand ratio of this column. {@code 0} to not have it
          *            expand at all. A negative number to clear the expand
          *            value.
+         * @return this column
          * @throws IllegalStateException
          *             if the column is no longer attached to any grid
          * @see #setWidth(double)
@@ -1607,6 +1622,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          * <p>
          * Equal to calling {@link #setExpandRatio(int) setExpandRatio(-1)}
          *
+         * @return this column
          * @throws IllegalStateException
          *             if the column is no longer attached to any grid
          */
@@ -1790,6 +1806,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          *
          * @param pixels
          *            the maximum width
+         * @return this column
          * @throws IllegalStateException
          *             if the column is no longer attached to any grid
          * @see #setExpandRatio(int)
@@ -1826,6 +1843,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          * @param resizable
          *            {@code true} if this column should be resizable,
          *            {@code false} otherwise
+         * @return this column
          * @throws IllegalStateException
          *             if the column is no longer attached to any grid
          */
@@ -1961,8 +1979,8 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          *            {@code true} if column is editable; {@code false} if not
          * @return this column
          * @throws IllegalStateException
-         *            if editable is true and column has no editor binding or
-         *            component defined
+         *             if editable is true and column has no editor binding or
+         *             component defined
          *
          * @see #setEditorComponent(HasValue, Setter)
          * @see #setEditorBinding(Binding)
@@ -2045,6 +2063,9 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          * <strong>Note:</strong> The same component cannot be used for multiple
          * columns.
          *
+         * @param <C>
+         *            a class that extends both {@link HasValue} and
+         *            {@link Component}
          * @param editorComponent
          *            the editor component
          * @param setter
@@ -2081,6 +2102,11 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          * <strong>Note:</strong> The same component cannot be used for multiple
          * columns.
          *
+         * @param <F>
+         *            a value type
+         * @param <C>
+         *            a class that extends both {@link HasValue} (for type
+         *            {@code <F>}) and {@link Component}
          * @param editorComponent
          *            the editor component
          * @return this column
@@ -2113,8 +2139,8 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
          * all currently available row data to be recreated and sent to the
          * client.
          *
-         * Note: Setting a new renderer will reset presentation provider if
-         * it exists.
+         * Note: Setting a new renderer will reset presentation provider if it
+         * exists.
          *
          * @param renderer
          *            the new renderer
@@ -2660,6 +2686,8 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      * @see Grid#Grid()
      * @see Grid#Grid(Class)
      *
+     * @param <BEAN>
+     *            the grid bean type
      * @param propertySet
      *            the property set implementation to use, not <code>null</code>.
      * @return a new grid using the provided property set, not <code>null</code>
@@ -2875,6 +2903,8 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      *
      * @param valueProvider
      *            the value provider
+     * @param <V>
+     *            the column value type
      *
      * @return the new column
      */
@@ -3061,8 +3091,8 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
     /**
      * Removes the given column from this {@link Grid}.
      *
-     * Note: If you have Editor with binding in this Grid to this property, you need to remove that
-     * using removeBinding method provided by Binder.
+     * Note: If you have Editor with binding in this Grid to this property, you
+     * need to remove that using removeBinding method provided by Binder.
      *
      * @param column
      *            the column to remove
@@ -4014,6 +4044,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      *
      * @see Column#setId(String)
      */
+    @SuppressWarnings("unchecked")
     public void setColumns(String... columnIds) {
         // Must extract to an explicitly typed variable because otherwise javac
         // cannot determine which overload of setColumnOrder to use
@@ -4068,6 +4099,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      * @param columns
      *            the columns in the order they should be
      */
+    @SuppressWarnings("unchecked")
     public void setColumnOrder(Column<T, ?>... columns) {
         setColumnOrder(Stream.of(columns));
     }
@@ -4133,6 +4165,11 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
         return new GridSingleSelect<>(this);
     }
 
+    /**
+     * Returns the {@link Editor} for this grid.
+     *
+     * @return the editor, not null
+     */
     public Editor<T> getEditor() {
         return editor;
     }
@@ -4223,6 +4260,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      *
      * @see #getSelectionModel()
      * @see GridSelectionModel
+     * @return the items in the current selection, not null
      */
     public Set<T> getSelectedItems() {
         return getSelectionModel().getSelectedItems();
@@ -4234,6 +4272,8 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      *
      * @see #getSelectionModel()
      * @see GridSelectionModel
+     * @param item
+     *            the item to select, not null
      */
     public void select(T item) {
         getSelectionModel().select(item);
@@ -4245,6 +4285,8 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      *
      * @see #getSelectionModel()
      * @see GridSelectionModel
+     * @param item
+     *            the item to deselect, not null
      */
     public void deselect(T item) {
         getSelectionModel().deselect(item);
@@ -4849,10 +4891,10 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      */
     protected void writeData(Element body, DesignContext designContext) {
         getDataProvider().fetch(new Query<>())
-                .forEach(item -> writeRow(body, item, designContext));
+                .forEach(item -> writeRow(body, item));
     }
 
-    private void writeRow(Element container, T item, DesignContext context) {
+    private void writeRow(Element container, T item) {
         Element tableRow = container.appendElement("tr");
         tableRow.attr("item", serializeDeclarativeRepresentation(item));
         if (getSelectionModel().isSelected(item)) {

server/src/main/java/com/vaadin/ui/GridLayout.java

@@ -641,6 +641,7 @@ public class GridLayout extends AbstractLayout
          * Constructs an <code>OverlapsException</code>.
          *
          * @param existingArea
+         *            the existing area that needs overlapping
          */
         public OverlapsException(Area existingArea) {
             this.existingArea = existingArea;
@@ -698,6 +699,7 @@ public class GridLayout extends AbstractLayout
          * detail message.
          *
          * @param areaOutOfBounds
+         *            the area that exceeds the bounds of the grid
          */
         public OutOfBoundsException(Area areaOutOfBounds) {
             super(String.format("%s, layout dimension: %sx%s", areaOutOfBounds,
@@ -837,6 +839,7 @@ public class GridLayout extends AbstractLayout
      * by GridLayout.
      *
      * @param cursorX
+     *            current cursor x-position
      */
     public void setCursorX(int cursorX) {
         this.cursorX = cursorX;
@@ -1058,7 +1061,9 @@ public class GridLayout extends AbstractLayout
      * @see #setWidth(float, Unit)
      *
      * @param columnIndex
+     *            The column index, starting from 0 for the leftmost row.
      * @param ratio
+     *            the expand ratio
      */
     public void setColumnExpandRatio(int columnIndex, float ratio) {
         columnExpandRatio.put(columnIndex, ratio);
@@ -1072,6 +1077,7 @@ public class GridLayout extends AbstractLayout
      * @see #setColumnExpandRatio(int, float)
      *
      * @param columnIndex
+     *            The column index, starting from 0 for the leftmost row.
      * @return the expand ratio, 0.0f by default
      */
     public float getColumnExpandRatio(int columnIndex) {
@@ -1103,6 +1109,7 @@ public class GridLayout extends AbstractLayout
      * @param rowIndex
      *            The row index, starting from 0 for the topmost row.
      * @param ratio
+     *            the expand ratio
      */
     public void setRowExpandRatio(int rowIndex, float ratio) {
         rowExpandRatio.put(rowIndex, ratio);
@@ -1195,6 +1202,7 @@ public class GridLayout extends AbstractLayout
      * MarginInfo )
      */
     @Override
+    @SuppressWarnings("deprecation")
     public void setMargin(MarginInfo marginInfo) {
         getState().marginsBitmask = marginInfo.getBitMask();
     }
@@ -1205,6 +1213,7 @@ public class GridLayout extends AbstractLayout
      * @see com.vaadin.ui.Layout.MarginHandler#getMargin()
      */
     @Override
+    @SuppressWarnings("deprecation")
     public MarginInfo getMargin() {
         return new MarginInfo(getState(false).marginsBitmask);
     }
@@ -1430,7 +1439,7 @@ public class GridLayout extends AbstractLayout
         }
 
         if (components.isEmpty()) {
-            writeEmptyColsAndRows(design, designContext);
+            writeEmptyColsAndRows(design);
             return;
         }
 
@@ -1566,10 +1575,8 @@ public class GridLayout extends AbstractLayout
      * components in the {@link GridLayout}
      *
      * @param design
-     * @param designContext
      */
-    private void writeEmptyColsAndRows(Element design,
-            DesignContext designContext) {
+    private void writeEmptyColsAndRows(Element design) {
         int rowCount = getState(false).rows;
         int colCount = getState(false).columns;
 

server/src/main/java/com/vaadin/ui/Panel.java

@@ -334,7 +334,7 @@ public class Panel extends AbstractSingleComponentContainer
     public void writeDesign(Element design, DesignContext designContext) {
         super.writeDesign(design, designContext);
         // handle tabindex
-        Panel def = designContext.getDefaultInstance(this);
+        designContext.getDefaultInstance(this);
     }
 
 }

server/src/main/java/com/vaadin/ui/TabSheet.java

@@ -140,7 +140,7 @@ public class TabSheet extends AbstractComponentContainer
         registerRpc(new FocusAndBlurServerRpcDecorator(this, this::fireEvent));
 
         // expand horizontally by default
-        setWidth(100, UNITS_PERCENTAGE);
+        setWidth(100, Unit.PERCENTAGE);
         setCloseHandler(TabSheet::removeComponent);
     }
 
@@ -450,8 +450,7 @@ public class TabSheet extends AbstractComponentContainer
 
     @Override
     public void moveComponentsFrom(ComponentContainer source) {
-        for (final Iterator<Component> i = source.getComponentIterator(); i
-                .hasNext();) {
+        for (final Iterator<Component> i = source.iterator(); i.hasNext();) {
             final Component c = i.next();
             String caption = null;
             Resource icon = null;
@@ -644,8 +643,7 @@ public class TabSheet extends AbstractComponentContainer
      */
     private boolean updateSelection() {
         Component originalSelection = selected;
-        for (final Iterator<Component> i = getComponentIterator(); i
-                .hasNext();) {
+        for (final Iterator<Component> i = iterator(); i.hasNext();) {
             final Component component = i.next();
 
             Tab tab = tabs.get(component);
@@ -851,7 +849,8 @@ public class TabSheet extends AbstractComponentContainer
      * @since 3.0
      */
     @FunctionalInterface
-    public interface SelectedTabChangeListener extends SerializableEventListener {
+    public interface SelectedTabChangeListener
+            extends SerializableEventListener {
 
         /**
          * Selected (shown) tab in tab sheet has has been changed.
@@ -1015,11 +1014,15 @@ public class TabSheet extends AbstractComponentContainer
 
         /**
          * Gets the caption for the tab.
+         *
+         * @return the caption
          */
         public String getCaption();
 
         /**
          * Gets the icon for the tab.
+         *
+         * @return tue icon resource
          */
         public Resource getIcon();
 
@@ -1036,6 +1039,8 @@ public class TabSheet extends AbstractComponentContainer
          *
          * @param icon
          *            the icon to set
+         * @param iconAltText
+         *            the alt text
          */
         public void setIcon(Resource icon, String iconAltText);
 
@@ -1043,6 +1048,8 @@ public class TabSheet extends AbstractComponentContainer
          * Gets the icon alt text for the tab.
          *
          * @since 7.2
+         *
+         * @return the alt text
          */
         public String getIconAlternateText();
 
@@ -1114,11 +1121,15 @@ public class TabSheet extends AbstractComponentContainer
          * TODO currently not sent to the client
          *
          * @see AbstractComponent#setComponentError(ErrorMessage)
+         *
+         * @return the error message
          */
         public ErrorMessage getComponentError();
 
         /**
          * Get the component related to the Tab.
+         *
+         * @return the component
          */
         public Component getComponent();
 
@@ -1407,6 +1418,7 @@ public class TabSheet extends AbstractComponentContainer
      * The default CloseHandler for TabSheet will only remove the tab.
      *
      * @param handler
+     *            the close handler that should be used
      */
     public void setCloseHandler(CloseHandler handler) {
         closeHandler = handler;
@@ -1434,7 +1446,8 @@ public class TabSheet extends AbstractComponentContainer
      *
      * @param tab
      *            The tab
-     * @return
+     * @return the index of the given tab, or -1 if there is no such tab in this
+     *         tabsheet
      */
     public int getTabPosition(Tab tab) {
         return components.indexOf(tab.getComponent());
@@ -1659,7 +1672,7 @@ public class TabSheet extends AbstractComponentContainer
     public void writeDesign(Element design, DesignContext designContext) {
         super.writeDesign(design, designContext);
         TabSheet def = designContext.getDefaultInstance(this);
-        Attributes attr = design.attributes();
+        design.attributes();
 
         // write tabs
         if (!designContext.shouldWriteChildren(this, def)) {

server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerPopup.java

@@ -15,7 +15,6 @@
  */
 package com.vaadin.ui.components.colorpicker;
 
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
@@ -28,19 +27,19 @@ import com.vaadin.data.HasValue;
 import com.vaadin.shared.Registration;
 import com.vaadin.shared.ui.MarginInfo;
 import com.vaadin.shared.ui.colorpicker.Color;
-import com.vaadin.ui.TabSheet;
-import com.vaadin.ui.Window;
-import com.vaadin.ui.VerticalLayout;
-import com.vaadin.ui.HorizontalLayout;
-import com.vaadin.ui.Component;
-import com.vaadin.ui.Slider;
-import com.vaadin.ui.Layout;
+import com.vaadin.ui.AbstractColorPicker.Coordinates2Color;
 import com.vaadin.ui.Alignment;
 import com.vaadin.ui.Button;
-import com.vaadin.ui.HasComponents;
-import com.vaadin.ui.AbstractColorPicker.Coordinates2Color;
 import com.vaadin.ui.Button.ClickEvent;
+import com.vaadin.ui.Component;
+import com.vaadin.ui.HasComponents;
+import com.vaadin.ui.HorizontalLayout;
+import com.vaadin.ui.Layout;
+import com.vaadin.ui.Slider;
 import com.vaadin.ui.Slider.ValueOutOfBoundsException;
+import com.vaadin.ui.TabSheet;
+import com.vaadin.ui.VerticalLayout;
+import com.vaadin.ui.Window;
 
 /**
  * A component that represents color selection popup within a color picker.
@@ -206,11 +205,6 @@ public class ColorPickerPopup extends Window implements HasValue<Color> {
         history.setWidth("97%");
         history.setHeight("22px");
 
-        // Create the default colors
-        List<Color> defaultColors = new ArrayList<>();
-        defaultColors.add(Color.BLACK);
-        defaultColors.add(Color.WHITE);
-
         // Create the history
         VerticalLayout innerContainer = new VerticalLayout();
         innerContainer.setWidth("100%");
@@ -503,6 +497,7 @@ public class ColorPickerPopup extends Window implements HasValue<Color> {
     }
 
     @Override
+    @SuppressWarnings("deprecation")
     public Registration addValueChangeListener(
             ValueChangeListener<Color> listener) {
         Objects.requireNonNull(listener, "listener cannot be null");

server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerPreview.java

@@ -49,8 +49,6 @@ public class ColorPickerPreview extends CssLayout implements HasValue<Color> {
     /** The field. */
     private final TextField field;
 
-    /** The old value. */
-    private String oldValue;
     private Registration valueChangeListenerRegistration = null;
 
     private boolean readOnly;
@@ -96,8 +94,6 @@ public class ColorPickerPreview extends CssLayout implements HasValue<Color> {
         field.setValue(colorCSS);
         field.setComponentError(null);
 
-        oldValue = colorCSS;
-
         // Re-register listener
         valueChangeListenerRegistration = field
                 .addValueChangeListener(this::valueChange);
@@ -121,6 +117,7 @@ public class ColorPickerPreview extends CssLayout implements HasValue<Color> {
     }
 
     @Override
+    @SuppressWarnings("deprecation")
     public Registration addValueChangeListener(
             ValueChangeListener<Color> listener) {
         Objects.requireNonNull(listener, "listener cannot be null");
@@ -141,7 +138,6 @@ public class ColorPickerPreview extends CssLayout implements HasValue<Color> {
              */
             color = ColorUtil.stringToColor(value);
 
-            oldValue = value;
             fireEvent(new ValueChangeEvent<>(this, oldColor,
                     event.isUserOriginated()));
         } catch (NumberFormatException e) {

server/src/main/java/com/vaadin/ui/declarative/DesignContext.java

@@ -354,10 +354,14 @@ public class DesignContext implements Serializable {
      * Returns the default instance for the given class. The instance must not
      * be modified by the caller.
      *
+     * @param <T>
+     *            a component class
      * @param component
+     *            the component that determines the class
      * @return the default instance for the given class. The return value must
      *         not be modified by the caller
      */
+    @SuppressWarnings("unchecked")
     public <T> T getDefaultInstance(Component component) {
         // If the root is a @DesignRoot component, it can't use itself as a
         // reference or the written design will be empty
@@ -385,6 +389,9 @@ public class DesignContext implements Serializable {
     /**
      * Reads and stores the mappings from prefixes to package names from meta
      * tags located under <head> in the html document.
+     *
+     * @param doc
+     *            the document
      */
     protected void readPackageMappings(Document doc) {
         Element head = doc.head();
@@ -848,7 +855,8 @@ public class DesignContext implements Serializable {
             String value) {
         Map<String, String> map = customAttributes.get(component);
         if (map == null) {
-            customAttributes.put(component, map = new HashMap<>());
+            map = new HashMap<>();
+            customAttributes.put(component, map);
         }
         map.put(attribute, value);
     }

server/src/test/java/com/vaadin/server/VaadinServletTest.java

@@ -233,7 +233,7 @@ public class VaadinServletTest {
     public void isAllowedVAADINResource_jarWarFileScheme_detectsAsStaticResources()
             throws IOException, URISyntaxException, ServletException {
         assertTrue("Can not run concurrently with other test",
-                VaadinServlet.openFileSystems.isEmpty());
+                VaadinServlet.OPEN_FILE_SYSTEMS.isEmpty());
 
         VaadinServlet servlet = new VaadinServlet();
         servlet.init(new MockServletConfig());
@@ -276,7 +276,7 @@ public class VaadinServletTest {
     public void isAllowedVAADINResource_jarInAJar_detectsAsStaticResources()
             throws IOException, URISyntaxException, ServletException {
         assertTrue("Can not run concurrently with other test",
-                VaadinServlet.openFileSystems.isEmpty());
+                VaadinServlet.OPEN_FILE_SYSTEMS.isEmpty());
 
         VaadinServlet servlet = new VaadinServlet();
         servlet.init(new MockServletConfig());
@@ -325,7 +325,7 @@ public class VaadinServletTest {
     public void openingJarFileSystemForDifferentFilesInSameJar_existingFileSystemIsUsed()
             throws IOException, URISyntaxException, ServletException {
         assertTrue("Can not run concurrently with other test",
-                VaadinServlet.openFileSystems.isEmpty());
+                VaadinServlet.OPEN_FILE_SYSTEMS.isEmpty());
 
         VaadinServlet servlet = new VaadinServlet();
         servlet.init(new MockServletConfig());
@@ -348,15 +348,15 @@ public class VaadinServletTest {
             servlet.getFileSystem(fileResourceURL.toURI());
 
             assertEquals("Same file should be marked for both resources",
-                    (Integer) 2, VaadinServlet.openFileSystems.entrySet()
+                    (Integer) 2, VaadinServlet.OPEN_FILE_SYSTEMS.entrySet()
                             .iterator().next().getValue());
             servlet.closeFileSystem(folderResourceURL.toURI());
             assertEquals("Closing resource should be removed from jar uri",
-                    (Integer) 1, VaadinServlet.openFileSystems.entrySet()
+                    (Integer) 1, VaadinServlet.OPEN_FILE_SYSTEMS.entrySet()
                             .iterator().next().getValue());
             servlet.closeFileSystem(fileResourceURL.toURI());
             assertTrue("Closing last resource should clear marking",
-                    VaadinServlet.openFileSystems.isEmpty());
+                    VaadinServlet.OPEN_FILE_SYSTEMS.isEmpty());
 
             try {
                 FileSystems.getFileSystem(folderResourceURL.toURI());
@@ -375,7 +375,7 @@ public class VaadinServletTest {
             throws IOException, InterruptedException, ExecutionException,
             URISyntaxException, ServletException {
         assertTrue("Can not run concurrently with other test",
-                VaadinServlet.openFileSystems.isEmpty());
+                VaadinServlet.OPEN_FILE_SYSTEMS.isEmpty());
 
         VaadinServlet servlet = new VaadinServlet();
         servlet.init(new MockServletConfig());
@@ -547,7 +547,7 @@ public class VaadinServletTest {
     private void ensureFileSystemsCleared(URL fileResourceURL)
             throws URISyntaxException {
         assertFalse("URI should have been cleared",
-                VaadinServlet.openFileSystems
+                VaadinServlet.OPEN_FILE_SYSTEMS
                         .containsKey(fileResourceURL.toURI()));
         try {
             FileSystems.getFileSystem(fileResourceURL.toURI());

testbench-api/src/main/java/com/vaadin/testbench/elements/AbstractComponentElement.java

@@ -34,9 +34,7 @@ public class AbstractComponentElement extends AbstractElement {
      */
     public String getCaption() {
         final String gwtIdAttribute = "aria-labelledby";
-        WebElement captElem = null;
-        String captionId = null;
-        captionId = getAttribute(gwtIdAttribute);
+        String captionId = getAttribute(gwtIdAttribute);
         // IE8 getAttribute returns empty string instead of null
         // when there is no attribute with specified name
         if (captionId == null || captionId.isEmpty()) {
@@ -45,7 +43,7 @@ public class AbstractComponentElement extends AbstractElement {
             captionId = elem.getAttribute(gwtIdAttribute);
         }
         // element ids are unique, we can search the whole page
-        captElem = getDriver().findElement(By.id(captionId));
+        WebElement captElem = getDriver().findElement(By.id(captionId));
         return captElem.getText();
     }
 

uitest/src/main/java/com/vaadin/tests/components/HasValueRequiredIndicator.java

@@ -22,11 +22,9 @@ import com.vaadin.ui.VerticalLayout;
  * @author Vaadin Ltd
  *
  */
-public abstract class HasValueRequiredIndicator<C extends HasValue & Component>
+public abstract class HasValueRequiredIndicator<C extends HasValue<?> & Component>
         extends AbstractTestUI {
 
-    private static final List<Class<? extends Layout>> LAYOUTS = getVaadinLayouts();
-
     @Override
     protected void setup(VaadinRequest request) {
         getContent().setSizeFull();
@@ -70,6 +68,7 @@ public abstract class HasValueRequiredIndicator<C extends HasValue & Component>
         if (type instanceof Class<?>) {
             Class<?> clazz = (Class<?>) type;
             try {
+                @SuppressWarnings("unchecked")
                 C component = (C) clazz.newInstance();
                 initValue(component);
                 component.setRequiredIndicatorVisible(true);

uitest/src/main/java/com/vaadin/tests/components/grid/GridNullSafeNestedPropertyColumn.java

@@ -20,8 +20,6 @@ public class GridNullSafeNestedPropertyColumn extends AbstractTestUI {
 
     private List<Person> personList = new ArrayList<>();
     private ListDataProvider<Person> listDataProvider;
-    private Grid.Column nullSafeColumn = null;
-    private Grid.Column regularColumn = null;
 
     @Override
     protected void setup(VaadinRequest request) {
@@ -47,8 +45,7 @@ public class GridNullSafeNestedPropertyColumn extends AbstractTestUI {
 
         Button addSafeColumnButton = new Button(
                 "add 'address.streetAddress' as a null-safe column", event -> {
-                    nullSafeColumn = grid.addColumn("address.streetAddress",
-                            new TextRenderer(),
+                    grid.addColumn("address.streetAddress", new TextRenderer(),
                             Grid.Column.NestedNullBehavior.ALLOW_NULLS);
                 });
         addSafeColumnButton.setId("safe");
@@ -56,7 +53,7 @@ public class GridNullSafeNestedPropertyColumn extends AbstractTestUI {
         Button addUnsafeColumnButton = new Button(
                 "add 'address.streetAddress' column without nested null safety",
                 event -> {
-                    regularColumn = grid.addColumn("address.streetAddress");
+                    grid.addColumn("address.streetAddress");
                 });
         addUnsafeColumnButton.setId("unsafe");
 

uitest/src/main/java/com/vaadin/tests/components/table/CollapseIndicatorOverlapsColumn.java

@@ -4,16 +4,17 @@ import com.vaadin.tests.components.TestBase;
 import com.vaadin.v7.data.Item;
 import com.vaadin.v7.ui.Table;
 
+@SuppressWarnings("deprecation")
 public class CollapseIndicatorOverlapsColumn extends TestBase {
 
     @Override
     protected void setup() {
         Table tbl = createTable();
-        tbl = createTable();
         tbl.setWidth("400px");
         addComponent(tbl);
     }
 
+    @SuppressWarnings("unchecked")
     private Table createTable() {
         Table tbl = new Table();
         tbl.addContainerProperty("COL1", String.class, "Column 1");

uitest/src/main/java/com/vaadin/tests/components/table/TableInTabsheet.java

@@ -1,7 +1,5 @@
 package com.vaadin.tests.components.table;
 
-import java.net.MalformedURLException;
-
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.shared.ui.ContentMode;
 import com.vaadin.tests.components.AbstractReindeerTestUI;
@@ -14,6 +12,7 @@ import com.vaadin.v7.ui.Table;
 import com.vaadin.v7.ui.Table.Align;
 import com.vaadin.v7.ui.themes.Reindeer;
 
+@SuppressWarnings("deprecation")
 public class TableInTabsheet extends AbstractReindeerTestUI {
 
     @Override
@@ -28,41 +27,30 @@ public class TableInTabsheet extends AbstractReindeerTestUI {
     }
 
     private VerticalLayout title() {
-
         VerticalLayout vP = new VerticalLayout();
         vP.setStyleName(Reindeer.LAYOUT_BLACK);
         Label tit = new Label("<h1> Tab/Table Test</h1>", ContentMode.HTML);
         vP.addComponent(tit);
         return vP;
-
     }
 
     private VerticalLayout page() {
-
         VerticalLayout vP = new VerticalLayout();
         vP.setStyleName(Reindeer.LAYOUT_BLUE);
         TabSheet t = new TabSheet();
         t.setWidth(1000, Unit.PIXELS);
 
         HorizontalLayout hP = new HorizontalLayout();
-        t.addTab(Ranking(), "Ranking");
-        try {
-
-            t.addTab(GDocs(""), "Dez 2011");
-            t.addTab(GDocs(""), "Jan 2012");
-            t.addTab(GDocs(""), "Abr 2012");
-
-        } catch (MalformedURLException e) {
-            e.printStackTrace();
-        }
+        t.addTab(createRankingLayout(), "Ranking");
+        t.addTab(createSimpleTabContent(), "Dez 2011");
+        t.addTab(createSimpleTabContent(), "Jan 2012");
+        t.addTab(createSimpleTabContent(), "Abr 2012");
         hP.addComponent(t);
         vP.addComponent(hP);
         return vP;
-
     }
 
-    private AbsoluteLayout Ranking() {
-
+    private AbsoluteLayout createRankingLayout() {
         AbsoluteLayout vT = new AbsoluteLayout();
         vT.setHeight(500, Unit.PIXELS);
         vT.setWidth(900, Unit.PIXELS);
@@ -86,22 +74,20 @@ public class TableInTabsheet extends AbstractReindeerTestUI {
 
         vT.addComponent(table, "left: 50px; top: 50px;");
         return vT;
-
     }
 
-    private VerticalLayout GDocs(String end) throws MalformedURLException {
-
+    private VerticalLayout createSimpleTabContent() {
         VerticalLayout vT = new VerticalLayout();
         vT.setHeight(500, Unit.PIXELS);
         vT.setWidth(900, Unit.PIXELS);
 
         return vT;
-
     }
 
     @Override
     protected String getTestDescription() {
-        return "Chaning to a different tab and then back to the first tab should properly render the table.";
+        return "Chaning to a different tab and then back to the first tab "
+                + "should properly render the table.";
     }
 
     @Override

uitest/src/main/java/com/vaadin/tests/components/treetable/TreeTableScrollOnExpand.java

@@ -4,6 +4,7 @@ import com.vaadin.server.VaadinRequest;
 import com.vaadin.tests.components.AbstractReindeerTestUI;
 import com.vaadin.v7.ui.TreeTable;
 
+@SuppressWarnings("deprecation")
 public class TreeTableScrollOnExpand extends AbstractReindeerTestUI {
 
     @Override
@@ -15,9 +16,9 @@ public class TreeTableScrollOnExpand extends AbstractReindeerTestUI {
         t.addContainerProperty("Name", String.class, "null");
         for (int i = 1; i <= 100; i++) {
             String parentID = "Item " + i;
-            Object parent = t.addItem(new Object[] { parentID }, parentID);
+            t.addItem(new Object[] { parentID }, parentID);
             String childID = "Item " + (100 + i);
-            Object child = t.addItem(new Object[] { childID }, childID);
+            t.addItem(new Object[] { childID }, childID);
             t.getContainerDataSource().setParent(childID, parentID);
         }
         addComponent(t);
@@ -30,7 +31,8 @@ public class TreeTableScrollOnExpand extends AbstractReindeerTestUI {
 
     @Override
     public String getTestDescription() {
-        return "After selecting an item and scrolling it out of view, TreeTable should not scroll to the "
+        return "After selecting an item and scrolling it out of view, "
+                + "TreeTable should not scroll to the "
                 + "selected item when expanding an item.";
     }
 }

uitest/src/main/java/com/vaadin/tests/components/uitest/components/AccordionsCssTest.java

@@ -8,14 +8,12 @@ import com.vaadin.ui.Label;
 import com.vaadin.v7.ui.themes.ChameleonTheme;
 import com.vaadin.v7.ui.themes.Runo;
 
+@SuppressWarnings("deprecation")
 public class AccordionsCssTest {
 
-    private TestSampler parent;
     private int debugIdCounter = 0;
 
     public AccordionsCssTest(TestSampler parent) {
-        this.parent = parent;
-
         Accordion def = createAccordionWith("Def Accordion", null);
         parent.addComponent(def);
 

uitest/src/main/java/com/vaadin/tests/dd/DDTest7.java

@@ -19,6 +19,7 @@ import com.vaadin.v7.event.DataBoundTransferable;
 import com.vaadin.v7.ui.AbstractSelect.AbstractSelectTargetDetails;
 import com.vaadin.v7.ui.Table;
 
+@SuppressWarnings("deprecation")
 public class DDTest7 extends TestBase {
 
     java.util.Random r = new java.util.Random(1);
@@ -135,11 +136,12 @@ public class DDTest7 extends TestBase {
 
             }
 
+            @SuppressWarnings("unchecked")
             private void moveAfter(IndexedContainer containerDataSource,
                     Object itemId, Object idAfter) {
                 try {
-                    IndexedContainer clone = null;
-                    clone = (IndexedContainer) containerDataSource.clone();
+                    IndexedContainer clone = (IndexedContainer) containerDataSource
+                            .clone();
                     containerDataSource.removeItem(itemId);
                     Item newItem = containerDataSource.addItemAfter(idAfter,
                             itemId);
@@ -158,6 +160,7 @@ public class DDTest7 extends TestBase {
 
     }
 
+    @SuppressWarnings("unchecked")
     private void populateTable() {
         table.addContainerProperty("Name", String.class, "");
         table.addContainerProperty("Weight", Integer.class, 0);

uitest/src/main/java/com/vaadin/tests/fieldgroup/FormWithNestedProperties.java

@@ -5,17 +5,15 @@ import com.vaadin.tests.data.bean.Address;
 import com.vaadin.tests.data.bean.Country;
 import com.vaadin.tests.data.bean.Person;
 import com.vaadin.tests.data.bean.Sex;
-import com.vaadin.tests.util.Log;
 import com.vaadin.ui.CheckBox;
 import com.vaadin.v7.data.fieldgroup.BeanFieldGroup;
 import com.vaadin.v7.ui.NativeSelect;
 import com.vaadin.v7.ui.TextField;
 
+@SuppressWarnings("deprecation")
 public class FormWithNestedProperties
         extends AbstractBeanFieldGroupTest<Person> {
 
-    private Log log = new Log(5);
-
     private TextField firstName = new TextField("First name");
     private TextField lastName = new TextField("Last name");
     private TextField email = new TextField("Email");
@@ -32,8 +30,8 @@ public class FormWithNestedProperties
         super.setup();
 
         setFieldBinder(new BeanFieldGroup<>(Person.class));
-        country = (NativeSelect) getFieldBinder().buildAndBind("country",
-                "address.country", NativeSelect.class);
+        country = getFieldBinder().buildAndBind("country", "address.country",
+                NativeSelect.class);
         getFieldBinder().bindMemberFields(this);
         addComponent(firstName);
         addComponent(lastName);

uitest/src/main/java/com/vaadin/tests/fonticon/FontIcons.java

@@ -46,6 +46,7 @@ import com.vaadin.v7.ui.TwinColSelect;
  * <p>
  * {@link VaadinIconSet} is the newer one for testing valo+vaadin icons.
  */
+@SuppressWarnings("deprecation")
 public class FontIcons extends AbstractReindeerTestUI {
 
     @Override
@@ -171,9 +172,9 @@ public class FontIcons extends AbstractReindeerTestUI {
         menu.setIcon(icon);
         menu.setCaption("MenuBar");
         MenuItem mi = menu.addItem("File", icon, null);
+        mi.addItem("Item", icon, null);
         MenuItem smi = mi.addItem("Item", icon, null);
-        smi = mi.addItem("Item", icon, null);
-        smi = smi.addItem("Item", icon, null);
+        smi.addItem("Item", icon, null);
         gl.addComponent(menu);
 
         // Tree, caption + item + subitem + action icons

uitest/src/main/java/com/vaadin/tests/minitutorials/v7b9/MessageView.java

@@ -9,7 +9,6 @@ import com.vaadin.ui.VerticalLayout;
 
 public class MessageView extends Panel implements View {
     public static final String NAME = "message";
-    private Layout layout;
 
     public MessageView() {
         super(new VerticalLayout());

uitest/src/main/java/com/vaadin/tests/util/LoggingItemDataProvider.java

@@ -15,8 +15,6 @@ import com.vaadin.ui.VerticalLayout;
 public class LoggingItemDataProvider
         extends CallbackDataProvider<String, String> {
 
-    private int counter;
-
     public LoggingItemDataProvider(int size, VerticalLayout logContainer) {
         super(q -> fetch(logContainer, q, size),
                 q -> size(logContainer, q, size));

uitest/src/main/java/com/vaadin/v7/tests/components/grid/GridThemeUI.java

@@ -21,16 +21,15 @@ import com.vaadin.v7.ui.Grid;
 import com.vaadin.v7.ui.NativeSelect;
 import com.vaadin.v7.ui.renderers.DateRenderer;
 
+@SuppressWarnings("deprecation")
 public class GridThemeUI extends AbstractTestUIWithLog {
 
-    private Grid grid;
-
     protected static String[] columns = { "firstName", "lastName", "gender",
             "birthDate", "age", "alive", "address.streetAddress",
             "address.postalCode", "address.city", "address.country" };
 
     protected BeanItemContainer<ComplexPerson> container = ComplexPerson
-            .createContainer(100);;
+            .createContainer(100);
     {
         container.addNestedContainerBean("address");
     }
@@ -113,7 +112,8 @@ public class GridThemeUI extends AbstractTestUIWithLog {
             b.setSizeFull();
             row.join("address.streetAddress", "address.postalCode",
                     "address.city", "address.country").setComponent(b);
-            // TODO: revert back to 25 when #16597 is fixed..
+            // NOTE: can't set column width that is too narrow to accommodate
+            // cell paddings, e.g. 25 would not be enough for Valo
             getColumn("age").setWidth(42);
             removeColumn("salary");
             setEditorEnabled(true);

uitest/src/main/java/com/vaadin/v7/tests/components/grid/basicfeatures/GridBasicFeatures.java

@@ -76,6 +76,7 @@ import com.vaadin.v7.ui.renderers.NumberRenderer;
  * @author Vaadin Ltd
  */
 @Theme("valo")
+@SuppressWarnings("deprecation")
 public class GridBasicFeatures extends AbstractComponentTest<Grid> {
 
     public static final String ROW_STYLE_GENERATOR_ROW_NUMBERS_FOR_3_OF_4 = "Row numbers for 3/4";
@@ -1017,7 +1018,6 @@ public class GridBasicFeatures extends AbstractComponentTest<Grid> {
     protected void createColumnActions() {
         createCategory("Columns", null);
         for (int c = 0; c < COLUMNS; c++) {
-            final int index = c;
             createCategory(getColumnProperty(c), "Columns");
 
             createClickAction("Add / Remove", getColumnProperty(c),