Simplify lambda expressions (#10198)

* Simplify lambda expressions

And remove unneeded 'return' keyword.

* Format

client/src/main/java/com/vaadin/client/ResourceLoader.java

@@ -492,9 +492,7 @@ public class ResourceLoader {
      */
     protected void runWhenHtmlImportsReady(Runnable runnable) {
         if (GWT.isClient() && supportsHtmlWhenReady()) {
-            addHtmlImportsReadyHandler(() -> {
-                runnable.run();
-            });
+            addHtmlImportsReadyHandler(() -> runnable.run());
         } else {
             runnable.run();
         }

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

@@ -254,7 +254,8 @@ public class GridConnector extends AbstractListingConnector
         getWidget().setRowStyleGenerator(rowRef -> {
             JsonObject json = rowRef.getRow();
             return json.hasKey(GridState.JSONKEY_ROWSTYLE)
-                    ? json.getString(GridState.JSONKEY_ROWSTYLE) : null;
+                    ? json.getString(GridState.JSONKEY_ROWSTYLE)
+                    : null;
         });
         getWidget().setCellStyleGenerator(cellRef -> {
             JsonObject row = cellRef.getRow();
@@ -401,10 +402,9 @@ public class GridConnector extends AbstractListingConnector
 
     private void updateStaticRow(RowState rowState,
             Grid.StaticSection.StaticRow row) {
-        rowState.cells.forEach((columnId, cellState) -> {
-            updateStaticCellFromState(row.getCell(getColumn(columnId)),
-                    cellState);
-        });
+        rowState.cells
+                .forEach((columnId, cellState) -> updateStaticCellFromState(
+                        row.getCell(getColumn(columnId)), cellState));
         for (Map.Entry<CellState, Set<String>> cellGroupEntry : rowState.cellGroups
                 .entrySet()) {
             Set<String> group = cellGroupEntry.getValue();

client/src/main/java/com/vaadin/client/extensions/DragSourceExtensionConnector.java

@@ -277,9 +277,8 @@ public class DragSourceExtensionConnector extends AbstractExtensionConnector {
                 WidgetUtil.getRelativeX(draggedElement, dragStartEvent)
                         - transformXOffset,
                 WidgetUtil.getRelativeY(draggedElement, dragStartEvent));
-        AnimationScheduler.get().requestAnimationFrame(timestamp -> {
-            clonedElement.removeFromParent();
-        }, clonedElement);
+        AnimationScheduler.get().requestAnimationFrame(
+                timestamp -> clonedElement.removeFromParent(), clonedElement);
     }
 
     /**
@@ -362,10 +361,10 @@ public class DragSourceExtensionConnector extends AbstractExtensionConnector {
                     .trim();
             return Integer.parseInt(x);
         } catch (NumberFormatException nfe) {
-            Logger.getLogger(DragSourceExtensionConnector.class.getName())
-                    .info("Unable to parse \"transform: translate(...)\" matrix "
-                            + n + ". value from computed style, matrix \""
-                            + matrix + "\", drag image might not be visible");
+            Logger.getLogger(DragSourceExtensionConnector.class.getName()).info(
+                    "Unable to parse \"transform: translate(...)\" matrix " + n
+                            + ". value from computed style, matrix \"" + matrix
+                            + "\", drag image might not be visible");
         }
         return 0;
     }
@@ -393,9 +392,11 @@ public class DragSourceExtensionConnector extends AbstractExtensionConnector {
             return;
         }
         style.clearProperty("transform");
-        AnimationScheduler.get().requestAnimationFrame(timestamp -> {
-            draggedElement.getStyle().setProperty("transform", transition);
-        }, draggedElement);
+        AnimationScheduler.get()
+                .requestAnimationFrame(
+                        timestamp -> draggedElement.getStyle()
+                                .setProperty("transform", transition),
+                        draggedElement);
     }
 
     /**

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

@@ -120,9 +120,8 @@ public class VRichTextArea extends Composite implements Field, KeyPressHandler,
             // Must wait until iframe is attached to be able to access body
             BodyElement rtaBody = IFrameElement.as(rta.getElement())
                     .getContentDocument().getBody();
-            addInputListener(rtaBody, event -> {
-                inputHandlers.forEach(handler -> handler.execute());
-            });
+            addInputListener(rtaBody, event -> inputHandlers
+                    .forEach(handler -> handler.execute()));
         });
 
         formatter = new VRichTextToolbar(rta);

client/src/main/java/com/vaadin/client/ui/richtextarea/RichTextAreaConnector.java

@@ -54,9 +54,8 @@ public class RichTextAreaConnector extends AbstractFieldConnector
                 flush();
             }
         });
-        getWidget().addInputHandler(() -> {
-            valueChangeHandler.scheduleValueChange();
-        });
+        getWidget().addInputHandler(
+                () -> valueChangeHandler.scheduleValueChange());
 
         registerRpc(RichTextAreaClientRpc.class,
                 new RichTextAreaClientRpcImpl());

client/src/main/java/com/vaadin/client/ui/textarea/TextAreaConnector.java

@@ -44,9 +44,9 @@ public class TextAreaConnector extends AbstractTextFieldConnector {
     protected void init() {
         super.init();
         getWidget().addChangeHandler(event -> sendValueChange());
-        getWidget().addDomHandler(event -> {
-            getValueChangeHandler().scheduleValueChange();
-        }, InputEvent.getType());
+        getWidget().addDomHandler(
+                event -> getValueChangeHandler().scheduleValueChange(),
+                InputEvent.getType());
 
         getWidget().addMouseUpHandler(new ResizeMouseUpHandler());
     }

client/src/main/java/com/vaadin/client/ui/textfield/TextFieldConnector.java

@@ -32,9 +32,9 @@ public class TextFieldConnector extends AbstractTextFieldConnector {
     protected void init() {
         super.init();
         getWidget().addChangeHandler(event -> sendValueChange());
-        getWidget().addDomHandler(event -> {
-            getValueChangeHandler().scheduleValueChange();
-        }, InputEvent.getType());
+        getWidget().addDomHandler(
+                event -> getValueChangeHandler().scheduleValueChange(),
+                InputEvent.getType());
     }
 
     @Override

client/src/main/java/com/vaadin/client/ui/treegrid/TreeGridConnector.java

@@ -64,9 +64,8 @@ public class TreeGridConnector extends GridConnector {
     }
 
     public TreeGridConnector() {
-        registerRpc(FocusRpc.class, (rowIndex, cellIndex) -> {
-            getWidget().focusCell(rowIndex, cellIndex);
-        });
+        registerRpc(FocusRpc.class, (rowIndex, cellIndex) -> getWidget()
+                .focusCell(rowIndex, cellIndex));
     }
 
     private String hierarchyColumnId;
@@ -237,7 +236,7 @@ public class TreeGridConnector extends GridConnector {
             GridEventHandler<?> eventHandler)
     /*-{
         var browserEventHandlers = grid.@com.vaadin.client.widgets.Grid::browserEventHandlers;
-    
+
         // FocusEventHandler is initially 5th in the list of browser event handlers
         browserEventHandlers.@java.util.List::set(*)(5, eventHandler);
     }-*/;

liferay-integration/src/main/java/com/vaadin/osgi/liferay/OsgiUIProvider.java

@@ -72,15 +72,11 @@ public class OsgiUIProvider extends UIProvider {
     public UI createInstance(UICreateEvent event) {
         if (prototype) {
             UI ui = serviceObjects.getService();
-            ui.addDetachListener(e -> {
-                serviceObjects.ungetService(ui);
-            });
+            ui.addDetachListener(e -> serviceObjects.ungetService(ui));
             return ui;
         }
-        logService.ifPresent(log -> {
-            log.log(LogService.LOG_WARNING,
-                    "UI services should have a prototype scope! Creating UI instance using the default constructor!");
-        });
+        logService.ifPresent(log -> log.log(LogService.LOG_WARNING,
+                "UI services should have a prototype scope! Creating UI instance using the default constructor!"));
         return super.createInstance(event);
     }
 

server/src/main/java/com/vaadin/data/Validator.java

@@ -186,10 +186,9 @@ public interface Validator<T>
             try {
                 if (guard.test(value)) {
                     return ValidationResult.ok();
-                } else {
-                    return ValidationResult.create(
-                            errorMessageProvider.apply(context), errorLevel);
                 }
+                return ValidationResult.create(
+                        errorMessageProvider.apply(context), errorLevel);
             } catch (Exception e) {
                 return ValidationResult.create(
                         errorMessageProvider.apply(context), errorLevel);

server/src/main/java/com/vaadin/data/converter/StringToBigIntegerConverter.java

@@ -84,13 +84,12 @@ public class StringToBigIntegerConverter
                 .map(number -> {
                     if (number == null) {
                         return null;
-                    } else {
-                        // Empty value will be a BigInteger
-                        if (number instanceof BigInteger) {
-                            return (BigInteger) number;
-                        }
-                        return ((BigDecimal) number).toBigInteger();
                     }
+                    // Empty value will be a BigInteger
+                    if (number instanceof BigInteger) {
+                        return (BigInteger) number;
+                    }
+                    return ((BigDecimal) number).toBigInteger();
                 });
     }
 

server/src/main/java/com/vaadin/data/converter/StringToDoubleConverter.java

@@ -72,9 +72,8 @@ public class StringToDoubleConverter
         return n.map(number -> {
             if (number == null) {
                 return null;
-            } else {
-                return number.doubleValue();
             }
+            return number.doubleValue();
         });
     }
 

server/src/main/java/com/vaadin/data/converter/StringToFloatConverter.java

@@ -70,9 +70,8 @@ public class StringToFloatConverter
         return n.map(number -> {
             if (number == null) {
                 return null;
-            } else {
-                return number.floatValue();
             }
+            return number.floatValue();
         });
     }
 

server/src/main/java/com/vaadin/data/converter/StringToIntegerConverter.java

@@ -85,18 +85,16 @@ public class StringToIntegerConverter
         return n.flatMap(number -> {
             if (number == null) {
                 return Result.ok(null);
-            } else {
-                int intValue = number.intValue();
-                if (intValue == number.longValue()) {
-                    // If the value of n is outside the range of long, the
-                    // return value of longValue() is either Long.MIN_VALUE or
-                    // Long.MAX_VALUE. The/ above comparison promotes int to
-                    // long and thus does not need to consider wrap-around.
-                    return Result.ok(intValue);
-                } else {
-                    return Result.error(getErrorMessage());
-                }
             }
+            int intValue = number.intValue();
+            if (intValue == number.longValue()) {
+                // If the value of n is outside the range of long, the
+                // return value of longValue() is either Long.MIN_VALUE or
+                // Long.MAX_VALUE. The/ above comparison promotes int to
+                // long and thus does not need to consider wrap-around.
+                return Result.ok(intValue);
+            }
+            return Result.error(getErrorMessage());
         });
     }
 

server/src/main/java/com/vaadin/data/converter/StringToLongConverter.java

@@ -85,9 +85,8 @@ public class StringToLongConverter
         return n.map(number -> {
             if (number == null) {
                 return null;
-            } else {
-                return number.longValue();
             }
+            return number.longValue();
         });
     }
 

server/src/main/java/com/vaadin/data/provider/InMemoryDataProviderHelpers.java

@@ -46,9 +46,8 @@ public class InMemoryDataProviderHelpers {
         UI currentUi = UI.getCurrent();
         if (currentUi != null) {
             return currentUi.getLocale();
-        } else {
-            return Locale.getDefault();
         }
+        return Locale.getDefault();
     };
 
     /**

server/src/main/java/com/vaadin/navigator/Navigator.java

@@ -120,10 +120,8 @@ public class Navigator implements Serializable {
                 popStateListenerRegistration = null;
             }
             if (navigator != null) {
-                popStateListenerRegistration = ui.getPage()
-                        .addPopStateListener(e -> {
-                            navigator.navigateTo(getState());
-                        });
+                popStateListenerRegistration = ui.getPage().addPopStateListener(
+                        e -> navigator.navigateTo(getState()));
             }
         }
 
@@ -700,10 +698,8 @@ public class Navigator implements Serializable {
      *            parameters passed in the navigation state to the view
      */
     protected void navigateTo(View view, String viewName, String parameters) {
-        runAfterLeaveConfirmation(() -> {
-            performNavigateTo(view, viewName, parameters);
-        });
-
+        runAfterLeaveConfirmation(
+                () -> performNavigateTo(view, viewName, parameters));
     }
 
     /**

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

@@ -694,9 +694,7 @@ public class FileUploadHandler implements RequestHandler {
 
     private void cleanStreamVariable(VaadinSession session, final UI ui,
             final ClientConnector owner, final String variableName) {
-        session.accessSynchronously(() -> {
-            ui.getConnectorTracker().cleanStreamVariable(owner.getConnectorId(),
-                    variableName);
-        });
+        session.accessSynchronously(() -> ui.getConnectorTracker()
+                .cleanStreamVariable(owner.getConnectorId(), variableName));
     }
 }

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

@@ -36,7 +36,6 @@ import org.atmosphere.interceptor.HeartbeatInterceptor;
 import org.atmosphere.util.VoidAnnotationProcessor;
 
 import com.vaadin.server.RequestHandler;
-import com.vaadin.server.ServiceDestroyEvent;
 import com.vaadin.server.ServiceException;
 import com.vaadin.server.ServletPortletHelper;
 import com.vaadin.server.SessionExpiredHandler;
@@ -66,9 +65,7 @@ public class PushRequestHandler
     public PushRequestHandler(VaadinServletService service)
             throws ServiceException {
 
-        service.addServiceDestroyListener((ServiceDestroyEvent event) -> {
-            destroy();
-        });
+        service.addServiceDestroyListener(e -> destroy());
 
         final ServletConfig vaadinServletConfig = service.getServlet()
                 .getServletConfig();

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

@@ -1388,10 +1388,10 @@ public abstract class AbstractComponent extends AbstractClientConnector
         // called if there are no listeners on the server-side. A client-side
         // connector can override this and use a different RPC channel.
         if (getRpcManager(ContextClickRpc.class.getName()) == null) {
-            registerRpc((ContextClickRpc) (MouseEventDetails details) -> {
-                fireEvent(
-                        new ContextClickEvent(AbstractComponent.this, details));
-            });
+            registerRpc(
+                    (ContextClickRpc) (MouseEventDetails details) -> fireEvent(
+                            new ContextClickEvent(AbstractComponent.this,
+                                    details)));
         }
 
         return addListener(EventId.CONTEXT_CLICK, ContextClickEvent.class,

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

@@ -678,10 +678,9 @@ public class ComboBox<T> extends AbstractSingleSelect<T>
     @Override
     public Registration addValueChangeListener(
             HasValue.ValueChangeListener<T> listener) {
-        return addSelectionListener(event -> {
-            listener.valueChange(new ValueChangeEvent<>(event.getComponent(),
-                    this, event.getOldValue(), event.isUserOriginated()));
-        });
+        return addSelectionListener(event -> listener
+                .valueChange(new ValueChangeEvent<>(event.getComponent(), this,
+                        event.getOldValue(), event.isUserOriginated())));
     }
 
     @Override

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

@@ -76,10 +76,10 @@ import com.vaadin.ui.declarative.DesignContext;
 public class CssLayout extends AbstractLayout implements LayoutClickNotifier {
 
     private CssLayoutServerRpc rpc = (MouseEventDetails mouseDetails,
-            Connector clickedConnector) -> {
-        fireEvent(LayoutClickEvent.createEvent(CssLayout.this, mouseDetails,
-                clickedConnector));
-    };
+            Connector clickedConnector) -> fireEvent(
+                    LayoutClickEvent.createEvent(CssLayout.this, mouseDetails,
+                            clickedConnector));
+
     /**
      * Custom layout slots containing the components.
      */

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

@@ -403,12 +403,12 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      *
      * <p>
      * Usage:
-     * 
+     *
      * <pre>
      * grid.addContextClickListener(event -&gt; Notification.show(
      *         ((GridContextClickEvent&lt;Person&gt;) event).getItem() + " Clicked"));
      * </pre>
-     * 
+     *
      * @param <T>
      *            the grid bean type
      */
@@ -836,9 +836,8 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
             String id = getId();
             if (id == null) {
                 return Stream.empty();
-            } else {
-                return Stream.of(new QuerySortOrder(id, direction));
             }
+            return Stream.of(new QuerySortOrder(id, direction));
         };
 
         private SerializableComparator<T> comparator;
@@ -3018,7 +3017,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      * Note that all header, body and footer rows get the same height if
      * explicitly set. In automatic mode, each section is calculated separately
      * based on an empty row of that type.
-     * 
+     *
      * @see #setBodyRowHeight(double)
      * @see #setHeaderRowHeight(double)
      * @see #setFooterRowHeight(double)
@@ -3036,7 +3035,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      * Sets the height of a body row. If -1 (default), the row height is
      * calculated based on the theme for an empty row before the Grid is
      * displayed.
-     * 
+     *
      * @param rowHeight
      *            The height of a row in pixels or -1 for automatic calculation
      * @since 8.2
@@ -3293,10 +3292,10 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
 
     /**
      * Sets the visibility of the Header in this Grid.
-     * 
+     *
      * @param headerVisible
      *            {@code true} if visible; {@code false} if not
-     * 
+     *
      * @since 8.1.1
      */
     public void setHeaderVisible(boolean headerVisible) {
@@ -3305,9 +3304,9 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
 
     /**
      * Gets the visibility of the Header in this Grid.
-     * 
+     *
      * @return {@code true} if visible; {@code false} if not
-     * 
+     *
      * @since 8.1.1
      */
     public boolean isHeaderVisible() {
@@ -3466,10 +3465,10 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
 
     /**
      * Sets the visibility of the Footer in this Grid.
-     * 
+     *
      * @param footerVisible
      *            {@code true} if visible; {@code false} if not
-     * 
+     *
      * @since 8.1.1
      */
     public void setFooterVisible(boolean footerVisible) {
@@ -3478,9 +3477,9 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
 
     /**
      * Gets the visibility of the Footer in this Grid.
-     * 
+     *
      * @return {@code true} if visible; {@code false} if not
-     * 
+     *
      * @since 8.1.1
      */
     public boolean isFooterVisible() {
@@ -3651,7 +3650,6 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
                         "setColumnOrder should not be called "
                                 + "with columns that are not in the grid.");
             }
-
         });
 
         List<String> stateColumnOrder = getState().columnOrder;
@@ -4572,14 +4570,13 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
      * @return the comparator based on column sorting information.
      */
     protected SerializableComparator<T> createSortingComparator() {
+        /*
+         * thenComparing is defined to return a serializable comparator as long
+         * as both original comparators are also serializable
+         */
         BinaryOperator<SerializableComparator<T>> operator = (comparator1,
-                comparator2) -> {
-            /*
-             * thenComparing is defined to return a serializable comparator as
-             * long as both original comparators are also serializable
-             */
-            return comparator1.thenComparing(comparator2)::compare;
-        };
+                comparator2) ->
+        comparator1.thenComparing(comparator2)::compare;
         return sortOrder.stream().map(
                 order -> order.getSorted().getComparator(order.getDirection()))
                 .reduce((x, y) -> 0, operator);

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

@@ -77,10 +77,10 @@ public class GridLayout extends AbstractLayout
         Layout.MarginHandler, LayoutClickNotifier {
 
     private GridLayoutServerRpc rpc = (MouseEventDetails mouseDetails,
-            Connector clickedConnector) -> {
-        fireEvent(LayoutClickEvent.createEvent(GridLayout.this, mouseDetails,
-                clickedConnector));
-    };
+            Connector clickedConnector) -> fireEvent(
+                    LayoutClickEvent.createEvent(GridLayout.this, mouseDetails,
+                            clickedConnector));
+
     /**
      * Cursor X position: this is where the next component with unspecified x,y
      * is inserted

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

@@ -33,9 +33,9 @@ import com.vaadin.shared.ui.image.ImageState;
 @SuppressWarnings("serial")
 public class Image extends AbstractEmbedded {
 
-    protected ImageServerRpc rpc = (MouseEventDetails mouseDetails) -> {
-        fireEvent(new ClickEvent(Image.this, mouseDetails));
-    };
+    protected ImageServerRpc rpc = (
+            MouseEventDetails mouseDetails) -> fireEvent(
+                    new ClickEvent(Image.this, mouseDetails));
 
     /**
      * Creates a new empty Image.

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

@@ -74,9 +74,8 @@ public class Notification extends AbstractExtension implements Serializable {
      *
      * @since 8.2
      */
-    protected NotificationServerRpc rpc = () -> {
-        fireEvent(new CloseEvent(Notification.this));
-    };
+    protected NotificationServerRpc rpc = () -> fireEvent(
+            new CloseEvent(Notification.this));
 
     public enum Type {
         HUMANIZED_MESSAGE("humanized"), WARNING_MESSAGE(

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

@@ -53,9 +53,8 @@ public class Panel extends AbstractSingleComponentContainer
      */
     protected ActionManager actionManager;
 
-    private PanelServerRpc rpc = (MouseEventDetails mouseDetails) -> {
-        fireEvent(new ClickEvent(Panel.this, mouseDetails));
-    };
+    private PanelServerRpc rpc = (MouseEventDetails mouseDetails) -> fireEvent(
+            new ClickEvent(Panel.this, mouseDetails));
 
     /**
      * Creates a new empty panel.

server/src/main/java/com/vaadin/ui/components/grid/GridDragSource.java

@@ -149,9 +149,8 @@ public class GridDragSource<T> extends DragSourceExtension<Grid<T>> {
     private void generateDragData(T item, JsonObject jsonObject) {
         JsonObject generatedValues = Json.createObject();
 
-        generatorFunctions.forEach((type, generator) -> {
-            generatedValues.put(type, generator.apply(item));
-        });
+        generatorFunctions.forEach((type, generator) -> generatedValues
+                .put(type, generator.apply(item)));
 
         jsonObject.put(GridDragSourceState.JSONKEY_DRAG_DATA, generatedValues);
     }

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

@@ -490,9 +490,8 @@ public class Design implements Serializable {
             // create listener for component creations that binds the created
             // components to the componentRoot instance fields
             ComponentCreationListener creationListener = (
-                    ComponentCreatedEvent event) -> {
-                binder.bindField(event.getComponent(), event.getLocalId());
-            };
+                    ComponentCreatedEvent event) -> binder.bindField(
+                            event.getComponent(), event.getLocalId());
             designContext.addComponentCreationListener(creationListener);
 
             // create subtree

server/src/main/java/com/vaadin/ui/dnd/DropTargetExtension.java

@@ -24,10 +24,10 @@ import java.util.Objects;
 import com.vaadin.server.AbstractExtension;
 import com.vaadin.shared.MouseEventDetails;
 import com.vaadin.shared.Registration;
-import com.vaadin.shared.ui.dnd.criteria.ComparisonOperator;
 import com.vaadin.shared.ui.dnd.DropEffect;
 import com.vaadin.shared.ui.dnd.DropTargetRpc;
 import com.vaadin.shared.ui.dnd.DropTargetState;
+import com.vaadin.shared.ui.dnd.criteria.ComparisonOperator;
 import com.vaadin.shared.ui.dnd.criteria.Criterion;
 import com.vaadin.ui.AbstractComponent;
 import com.vaadin.ui.dnd.event.DropEvent;
@@ -73,11 +73,10 @@ public class DropTargetExtension<T extends AbstractComponent>
      */
     protected void registerDropTargetRpc() {
         registerRpc(
-                (DropTargetRpc) (types, data, dropEffect, mouseEventDetails) -> {
-                    onDrop(types, data,
-                            DropEffect.valueOf(dropEffect.toUpperCase()),
-                            mouseEventDetails);
-                });
+                (DropTargetRpc) (types, data, dropEffect, mouseEventDetails) ->
+                onDrop(types, data,
+                        DropEffect.valueOf(dropEffect.toUpperCase()),
+                        mouseEventDetails));
     }
 
     /**

server/src/test/java/com/vaadin/data/BinderConverterValidatorTest.java

@@ -127,9 +127,8 @@ public class BinderConverterValidatorTest
         Validator<Number> positiveNumberValidator = (value, context) -> {
             if (value.doubleValue() >= 0) {
                 return ValidationResult.ok();
-            } else {
-                return ValidationResult.error(NEGATIVE_ERROR_MESSAGE);
             }
+            return ValidationResult.error(NEGATIVE_ERROR_MESSAGE);
         };
         binder.forField(salaryField)
                 .withConverter(Double::valueOf, String::valueOf)
@@ -227,7 +226,8 @@ public class BinderConverterValidatorTest
                 .withConverter(presentation -> {
                     if (presentation.equals("OK")) {
                         return "1";
-                    } else if (presentation.equals("NOTOK")) {
+                    }
+                    if (presentation.equals("NOTOK")) {
                         return "2";
                     }
                     throw new IllegalArgumentException(
@@ -235,12 +235,12 @@ public class BinderConverterValidatorTest
                 }, model -> {
                     if (model.equals("1")) {
                         return "OK";
-                    } else if (model.equals("2")) {
+                    }
+                    if (model.equals("2")) {
                         return "NOTOK";
-                    } else {
-                        throw new IllegalArgumentException(
-                                "Value in model must be 1 or 2");
                     }
+                    throw new IllegalArgumentException(
+                            "Value in model must be 1 or 2");
                 });
         binding.bind(StatusBean::getStatus, StatusBean::setStatus);
         binder.setBean(bean);
@@ -535,12 +535,9 @@ public class BinderConverterValidatorTest
         binder.forField(nameField).withConverter(fieldValue -> {
             if ("null".equals(fieldValue)) {
                 return null;
-            } else {
-                return fieldValue;
             }
-        }, model -> {
-            return model;
-        }).bind(Person::getFirstName, Person::setFirstName);
+            return fieldValue;
+        }, model -> model).bind(Person::getFirstName, Person::setFirstName);
 
         Person person = new Person();
         person.setFirstName("foo");

server/src/test/java/com/vaadin/data/BinderTest.java

@@ -394,8 +394,9 @@ public class BinderTest extends BinderTestBase<Binder<Person>, Person> {
         String customNullPointerRepresentation = "foo";
         Binder<Person> binder = new Binder<>(Person.class);
         binder.forField(nameField)
-                .withConverter(value -> value, value -> value == null
-                        ? customNullPointerRepresentation : value)
+                .withConverter(value -> value,
+                        value -> value == null ? customNullPointerRepresentation
+                                : value)
                 .bind("firstName");
 
         Person person = new Person();
@@ -892,9 +893,8 @@ public class BinderTest extends BinderTestBase<Binder<Person>, Person> {
                 .withConverter(new StringToIntegerConverter(ageError))
                 .bind(Person::getAge, Person::setAge);
 
-        binder.setValidationStatusHandler(status -> {
-            status.notifyBindingValidationStatusHandlers();
-        });
+        binder.setValidationStatusHandler(
+                status -> status.notifyBindingValidationStatusHandlers());
 
         String initialName = item.getFirstName();
         int initialAge = item.getAge();

server/src/test/java/com/vaadin/data/BinderValidationStatusTest.java

@@ -215,17 +215,16 @@ public class BinderValidationStatusTest
     public void binderWithStatusHandler_fieldValidationNoBeanValidation_handlerGetsStatusUpdates() {
         AtomicReference<BinderValidationStatus<?>> statusCapture = new AtomicReference<>();
         binder.forField(nameField).withValidator(notEmpty)
-                .withValidationStatusHandler(evt -> {
-                    fail("Using a custom status change handler so no change should end up here");
-                }).bind(Person::getFirstName, Person::setFirstName);
+                .withValidationStatusHandler(evt -> fail(
+                        "Using a custom status change handler so no change should end up here"))
+                .bind(Person::getFirstName, Person::setFirstName);
         binder.forField(ageField).withConverter(stringToInteger)
-                .withValidator(notNegative).withValidationStatusHandler(evt -> {
-                    fail("Using a custom status change handler so no change should end up here");
-                }).bind(Person::getAge, Person::setAge);
+                .withValidator(notNegative)
+                .withValidationStatusHandler(evt -> fail(
+                        "Using a custom status change handler so no change should end up here"))
+                .bind(Person::getAge, Person::setAge);
 
-        binder.setValidationStatusHandler(r -> {
-            statusCapture.set(r);
-        });
+        binder.setValidationStatusHandler(r -> statusCapture.set(r));
         binder.setBean(item);
         assertNull(nameField.getComponentError());
 
@@ -303,20 +302,19 @@ public class BinderValidationStatusTest
     public void binderWithStatusHandler_fieldAndBeanLevelValidation_handlerGetsStatusUpdates() {
         AtomicReference<BinderValidationStatus<?>> statusCapture = new AtomicReference<>();
         binder.forField(nameField).withValidator(notEmpty)
-                .withValidationStatusHandler(evt -> {
-                    fail("Using a custom status change handler so no change should end up here");
-                }).bind(Person::getFirstName, Person::setFirstName);
+                .withValidationStatusHandler(evt -> fail(
+                        "Using a custom status change handler so no change should end up here"))
+                .bind(Person::getFirstName, Person::setFirstName);
         binder.forField(ageField).withConverter(stringToInteger)
-                .withValidator(notNegative).withValidationStatusHandler(evt -> {
-                    fail("Using a custom status change handler so no change should end up here");
-                }).bind(Person::getAge, Person::setAge);
+                .withValidator(notNegative)
+                .withValidationStatusHandler(evt -> fail(
+                        "Using a custom status change handler so no change should end up here"))
+                .bind(Person::getAge, Person::setAge);
         binder.withValidator(
                 bean -> !bean.getFirstName().isEmpty() && bean.getAge() > 0,
                 "Need first name and age");
 
-        binder.setValidationStatusHandler(r -> {
-            statusCapture.set(r);
-        });
+        binder.setValidationStatusHandler(r -> statusCapture.set(r));
         binder.setBean(item);
         assertNull(nameField.getComponentError());
 
@@ -489,13 +487,9 @@ public class BinderValidationStatusTest
         BindingBuilder<Person, String> binding = binder.forField(nameField);
         binding.bind(Person::getFirstName, Person::setFirstName);
 
-        binder.setValidationStatusHandler(results -> {
-            fail();
-        });
+        binder.setValidationStatusHandler(results -> fail());
 
-        binder.setValidationStatusHandler(results -> {
-            capture.set(results);
-        });
+        binder.setValidationStatusHandler(results -> capture.set(results));
 
         nameField.setValue("foo");
         binder.validate();

server/src/test/java/com/vaadin/data/ValidatorTest.java

@@ -61,7 +61,8 @@ public class ValidatorTest extends ValidatorTestBase {
 
                     if (locale.getLanguage().equals("fi")) {
                         return finnishError;
-                    } else if (locale.getLanguage().equals("en")) {
+                    }
+                    if (locale.getLanguage().equals("en")) {
                         return englishError;
                     }
                     return notTranslatableError;

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

@@ -158,9 +158,8 @@ public class VaadinServiceTest {
 
         MockVaadinSession session = new MockVaadinSession(service);
         session.lock();
-        service.accessSession(session, () -> {
-            CurrentInstance.set(String.class, "Set in task");
-        });
+        service.accessSession(session,
+                () -> CurrentInstance.set(String.class, "Set in task"));
 
         CurrentInstance.set(String.class, "Original value");
         service.runPendingAccessTasks(session);

server/src/test/java/com/vaadin/tests/data/converter/ConverterTest.java

@@ -14,9 +14,8 @@ public class ConverterTest {
     SerializableFunction<String, Result<String>> toModel = presentation -> {
         if (presentation.startsWith("presentation-")) {
             return Result.ok(presentation.substring("presentation-".length()));
-        } else {
-            return Result.error("invalid prefix: " + presentation);
         }
+        return Result.error("invalid prefix: " + presentation);
     };
 
     SerializableFunction<String, String> toPresentation = model -> "presentation-"

server/src/test/java/com/vaadin/tests/design/designroot/ExtendedDesignWithEmptyAnnotation.java

@@ -15,7 +15,6 @@
  */
 package com.vaadin.tests.design.designroot;
 
-import com.vaadin.ui.Button.ClickEvent;
 import com.vaadin.ui.Notification;
 import com.vaadin.ui.TextField;
 
@@ -29,12 +28,8 @@ public class ExtendedDesignWithEmptyAnnotation
         customField.setPlaceholder("Something");
         addComponent(customField);
 
-        ok.addClickListener((ClickEvent event) -> {
-            Notification.show("OK");
-        });
+        ok.addClickListener(e -> Notification.show("OK"));
 
-        CaNCEL.addClickListener((ClickEvent event) -> {
-            Notification.show("cancel");
-        });
+        CaNCEL.addClickListener(e -> Notification.show("cancel"));
     }
 }

server/src/test/java/com/vaadin/tests/server/component/button/ButtonClickTest.java

@@ -10,7 +10,6 @@ import org.junit.Test;
 
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.ui.Button;
-import com.vaadin.ui.Button.ClickEvent;
 import com.vaadin.ui.UI;
 
 /**
@@ -23,9 +22,7 @@ public class ButtonClickTest {
     public void clickDetachedButton() {
         Button b = new Button();
         AtomicInteger counter = new AtomicInteger(0);
-        b.addClickListener((ClickEvent event) -> {
-            counter.incrementAndGet();
-        });
+        b.addClickListener(e -> counter.incrementAndGet());
 
         b.click();
         assertEquals(1, counter.get());
@@ -65,8 +62,6 @@ public class ButtonClickTest {
 
     private void addClickListener(Button b) {
         clicked = false;
-        b.addClickListener((ClickEvent ev) -> {
-            clicked = true;
-        });
+        b.addClickListener(e -> clicked = true);
     }
 }

server/src/test/java/com/vaadin/tests/server/component/window/AttachDetachWindowTest.java

@@ -3,15 +3,12 @@ package com.vaadin.tests.server.component.window;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 
-import org.junit.Assert;
 import org.junit.Test;
 
 import com.vaadin.server.ClientConnector;
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.server.VaadinSession;
 import com.vaadin.tests.util.AlwaysLockedVaadinSession;
-import com.vaadin.ui.HasComponents.ComponentAttachEvent;
-import com.vaadin.ui.HasComponents.ComponentDetachEvent;
 import com.vaadin.ui.Label;
 import com.vaadin.ui.UI;
 import com.vaadin.ui.VerticalLayout;
@@ -222,12 +219,10 @@ public class AttachDetachWindowTest {
         final Window window = new Window();
 
         final boolean[] eventFired = new boolean[1];
-        ui.addComponentAttachListener((ComponentAttachEvent event) -> {
-            eventFired[0] = event.getAttachedComponent().equals(window);
-        });
+        ui.addComponentAttachListener(
+                e -> eventFired[0] = e.getAttachedComponent().equals(window));
         ui.addWindow(window);
-        assertTrue("Attach event is not fired for added window",
-                eventFired[0]);
+        assertTrue("Attach event is not fired for added window", eventFired[0]);
     }
 
     @Test
@@ -236,9 +231,8 @@ public class AttachDetachWindowTest {
         final Window window = new Window();
 
         final boolean[] eventFired = new boolean[1];
-        ui.addComponentDetachListener((ComponentDetachEvent event) -> {
-            eventFired[0] = event.getDetachedComponent().equals(window);
-        });
+        ui.addComponentDetachListener(
+                e -> eventFired[0] = e.getDetachedComponent().equals(window));
         ui.addWindow(window);
         ui.removeWindow(window);
 

server/src/test/java/com/vaadin/tests/server/navigator/NavigatorTest.java

@@ -1283,9 +1283,7 @@ public class NavigatorTest {
         navigator.navigateTo("view1");
 
         AtomicInteger leaveCount = new AtomicInteger(0);
-        navigator.runAfterLeaveConfirmation(() -> {
-            leaveCount.incrementAndGet();
-        });
+        navigator.runAfterLeaveConfirmation(() -> leaveCount.incrementAndGet());
         assertEquals(0, leaveCount.get());
         eventRef.get().navigate();
         assertEquals(1, leaveCount.get());

server/src/test/java/com/vaadin/ui/CheckBoxTest.java

@@ -49,9 +49,8 @@ public class CheckBoxTest {
         CheckBox cb = new CheckBox();
         ui.setContent(cb);
         AtomicBoolean userOriginated = new AtomicBoolean(false);
-        cb.addValueChangeListener(e -> {
-            userOriginated.set(e.isUserOriginated());
-        });
+        cb.addValueChangeListener(
+                e -> userOriginated.set(e.isUserOriginated()));
         ComponentTest.syncToClient(cb);
         ServerRpcManager.getRpcProxy(cb, CheckBoxServerRpc.class)
                 .setChecked(true, new MouseEventDetails());
@@ -69,9 +68,8 @@ public class CheckBoxTest {
         CheckBox cb = new CheckBox();
         ui.setContent(cb);
         AtomicBoolean userOriginated = new AtomicBoolean(true);
-        cb.addValueChangeListener(e -> {
-            userOriginated.set(e.isUserOriginated());
-        });
+        cb.addValueChangeListener(
+                e -> userOriginated.set(e.isUserOriginated()));
         cb.setValue(true);
         assertFalse(userOriginated.get());
         userOriginated.set(true);

test/servlet-containers/karaf/vaadin-karaf-bundle1/src/main/java/com/vaadin/test/osgi/myapplication1/MyUI.java

@@ -2,11 +2,11 @@ package com.vaadin.test.osgi.myapplication1;
 
 import javax.servlet.annotation.WebServlet;
 
-import com.vaadin.annotations.Theme;
-import com.vaadin.annotations.Widgetset;
 import org.osgi.service.component.annotations.Component;
 
+import com.vaadin.annotations.Theme;
 import com.vaadin.annotations.VaadinServletConfiguration;
+import com.vaadin.annotations.Widgetset;
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.server.VaadinServlet;
 import com.vaadin.ui.Button;
@@ -27,9 +27,8 @@ public class MyUI extends UI {
         name.setCaption("Type your name here:");
 
         Button button = new Button("Click Me");
-        button.addClickListener(e -> {
-            layout.addComponent(new Label("Thanks " + name.getValue() + ", it works!"));
-        });
+        button.addClickListener(e -> layout.addComponent(
+                new Label("Thanks " + name.getValue() + ", it works!")));
 
         layout.addComponents(name, button);
 

test/servlet-containers/karaf/vaadin-karaf-bundle2/src/main/java/com/vaadin/test/osgi/myapplication/MyUI.java

@@ -23,9 +23,8 @@ public class MyUI extends UI {
         name.setCaption("Type your name here:");
 
         Button button = new Button("Click Me");
-        button.addClickListener(e -> {
-            layout.addComponent(new Label("Thanks " + name.getValue() + ", it works!"));
-        });
+        button.addClickListener(e -> layout.addComponent(
+                new Label("Thanks " + name.getValue() + ", it works!")));
 
         layout.addComponents(name, button);
 

uitest/src/main/java/com/vaadin/tests/components/abstractlisting/AbstractListingTestUI.java

@@ -29,9 +29,7 @@ public abstract class AbstractListingTestUI<T extends AbstractListing<Object>>
         options.put("100000", 100000);
 
         createSelectAction("Items", "Data provider", options, "20",
-                (c, number, data) -> {
-                    c.setItems(createItems(number));
-                });
+                (c, number, data) -> c.setItems(createItems(number)));
     }
 
     protected Object[] createItems(int number) {

uitest/src/main/java/com/vaadin/tests/components/abstractlisting/AbstractSingleSelectTestUI.java

@@ -45,9 +45,7 @@ public abstract class AbstractSingleSelectTestUI<T extends AbstractSingleSelect<
         options.put("Item 100", "Item 100");
 
         createSelectAction("Select", "Selection", options, "None",
-                (component, selected, data) -> {
-                    component.setValue(selected);
-                });
+                (component, selected, data) -> component.setValue(selected));
     }
 
 }

uitest/src/main/java/com/vaadin/tests/components/abstractsingleselect/AbstractSingleSelection.java

@@ -25,9 +25,9 @@ public class AbstractSingleSelection extends AbstractTestUI {
         componentSelect.setItemCaptionGenerator(Class::getSimpleName);
 
         componentSelect.setEmptySelectionAllowed(false);
-        componentSelect.addValueChangeListener(singleSelectClass -> {
-            createComponent(singleSelectClass.getValue());
-        });
+        componentSelect
+                .addValueChangeListener(singleSelectClass -> createComponent(
+                        singleSelectClass.getValue()));
 
         addComponent(componentSelect);
         addComponent(component); // This will be replaced in createComponent

uitest/src/main/java/com/vaadin/tests/components/composite/CompositeChainUI.java

@@ -46,10 +46,8 @@ public class CompositeChainUI extends AbstractTestUIWithLog {
         addComponent(container);
 
         Button updateCaption = new Button("Update caption");
-        updateCaption.addClickListener(e -> {
-            innermostComponent
-                    .setCaption(innermostComponent.getCaption() + " - updated");
-        });
+        updateCaption.addClickListener(e -> innermostComponent
+                .setCaption(innermostComponent.getCaption() + " - updated"));
         addComponent(updateCaption);
         Button replaceWithAnotherComposite = new Button(
                 "Replace with another Composite", e -> {

uitest/src/main/java/com/vaadin/tests/components/datefield/DateFieldElementUI.java

@@ -20,31 +20,27 @@ public class DateFieldElementUI extends AbstractReindeerTestUIWithLog {
     protected void setup(VaadinRequest request) {
         log.setNumberLogRows(false);
         DateField df = new DateField();
-        df.addValueChangeListener(event -> {
-            log("Default date field value set to " + event.getValue());
-        });
+        df.addValueChangeListener(event -> log(
+                "Default date field value set to " + event.getValue()));
         addComponent(df);
         InlineDateField inlineDateField = new InlineDateField();
-        inlineDateField.addValueChangeListener(event -> {
-            log("Default inline date field value set to " + event.getValue());
-        });
+        inlineDateField.addValueChangeListener(event -> log(
+                "Default inline date field value set to " + event.getValue()));
         addComponent(inlineDateField);
 
         DateField finnishDatefield = new DateField("Finnish");
         finnishDatefield.setId("fi");
         finnishDatefield.setLocale(new Locale("fi", "FI"));
         finnishDatefield.setValue(TEST_DATE_TIME);
-        finnishDatefield.addValueChangeListener(event -> {
-            log("Finnish date field value set to " + event.getValue());
-        });
+        finnishDatefield.addValueChangeListener(event -> log(
+                "Finnish date field value set to " + event.getValue()));
         addComponent(finnishDatefield);
         DateField usDatefield = new DateField("US");
         usDatefield.setId("us");
         usDatefield.setLocale(Locale.US);
         usDatefield.setValue(TEST_DATE_TIME);
-        usDatefield.addValueChangeListener(event -> {
-            log("US date field value set to " + event.getValue());
-        });
+        usDatefield.addValueChangeListener(
+                event -> log("US date field value set to " + event.getValue()));
         addComponent(usDatefield);
     }
 

uitest/src/main/java/com/vaadin/tests/components/datefield/DateTimeFieldElementUI.java

@@ -20,31 +20,27 @@ public class DateTimeFieldElementUI extends AbstractReindeerTestUIWithLog {
     protected void setup(VaadinRequest request) {
         log.setNumberLogRows(false);
         DateTimeField df = new DateTimeField();
-        df.addValueChangeListener(event -> {
-            log("Default date field value set to " + event.getValue());
-        });
+        df.addValueChangeListener(event -> log(
+                "Default date field value set to " + event.getValue()));
         addComponent(df);
         InlineDateTimeField inlineDateTimeField = new InlineDateTimeField();
-        inlineDateTimeField.addValueChangeListener(event -> {
-            log("Default inline date field value set to " + event.getValue());
-        });
+        inlineDateTimeField.addValueChangeListener(event -> log(
+                "Default inline date field value set to " + event.getValue()));
         addComponent(inlineDateTimeField);
 
         DateTimeField finnishDateTimeField = new DateTimeField("Finnish");
         finnishDateTimeField.setId("fi");
         finnishDateTimeField.setLocale(new Locale("fi", "FI"));
         finnishDateTimeField.setValue(TEST_DATE_TIME);
-        finnishDateTimeField.addValueChangeListener(event -> {
-            log("Finnish date field value set to " + event.getValue());
-        });
+        finnishDateTimeField.addValueChangeListener(event -> log(
+                "Finnish date field value set to " + event.getValue()));
         addComponent(finnishDateTimeField);
         DateTimeField usDateTimeField = new DateTimeField("US");
         usDateTimeField.setId("us");
         usDateTimeField.setLocale(Locale.US);
         usDateTimeField.setValue(TEST_DATE_TIME);
-        usDateTimeField.addValueChangeListener(event -> {
-            log("US date field value set to " + event.getValue());
-        });
+        usDateTimeField.addValueChangeListener(
+                event -> log("US date field value set to " + event.getValue()));
         addComponent(usDateTimeField);
     }
 

uitest/src/main/java/com/vaadin/tests/components/draganddropwrapper/DragAndDropFocusObtain.java

@@ -49,10 +49,9 @@ public class DragAndDropFocusObtain extends AbstractTestUIWithLog {
         }
     };
 
-    private ValueChangeListener<String> listener = event -> {
-        log("Value of " + ((AbstractTextField) event.getSource()).getCaption()
-                + " changed to " + event.getValue());
-    };
+    private ValueChangeListener<String> listener = event -> log(
+            "Value of " + ((AbstractTextField) event.getSource()).getCaption()
+                    + " changed to " + event.getValue());
 
     @Override
     protected void setup(VaadinRequest request) {

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

@@ -37,14 +37,12 @@ public class GridAriaMultiselectable extends AbstractTestUI {
 
         addComponent(grid);
 
-        Button singleSelectBtn = new Button("SingleSelect", event -> {
-            grid.setSelectionMode(SelectionMode.SINGLE);
-        });
+        Button singleSelectBtn = new Button("SingleSelect",
+                event -> grid.setSelectionMode(SelectionMode.SINGLE));
         addComponent(singleSelectBtn);
 
-        Button multiSelectBtn = new Button("MultiSelect", event -> {
-            grid.setSelectionMode(SelectionMode.MULTI);
-        });
+        Button multiSelectBtn = new Button("MultiSelect",
+                event -> grid.setSelectionMode(SelectionMode.MULTI));
         addComponent(multiSelectBtn);
     }
 }

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

@@ -20,7 +20,6 @@ import com.vaadin.server.VaadinRequest;
 import com.vaadin.tests.components.AbstractTestUI;
 import com.vaadin.ui.Button;
 import com.vaadin.ui.Grid;
-import com.vaadin.ui.Grid.SelectionMode;
 
 /**
  * @author Vaadin Ltd
@@ -36,19 +35,22 @@ public class GridAriaRowcount extends AbstractTestUI {
         addComponent(grid);
 
         addComponent(new Button("addFooter", event -> grid.addFooterRowAt(0)));
-        addComponent(new Button("removeFooter", event -> grid.removeFooterRow(0)));
+        addComponent(
+                new Button("removeFooter", event -> grid.removeFooterRow(0)));
 
         addComponent(new Button("addHeader", event -> grid.addHeaderRowAt(1)));
-        addComponent(new Button("removeHeader", event -> grid.removeHeaderRow(1)));
+        addComponent(
+                new Button("removeHeader", event -> grid.removeHeaderRow(1)));
 
-        addComponent(new Button("setItemsTo3", event -> grid.setItems("a", "b", "c")));
-        addComponent(new Button("setItemsTo6", event -> grid.setItems("a", "b", "c", "d", "e", "f")));
+        addComponent(new Button("setItemsTo3",
+                event -> grid.setItems("a", "b", "c")));
+        addComponent(new Button("setItemsTo6",
+                event -> grid.setItems("a", "b", "c", "d", "e", "f")));
 
         addComponent(new Button("updateAll", event -> {
             grid.addFooterRowAt(0);
             grid.addHeaderRowAt(0);
             grid.setItems("a", "b", "c", "d");
         }));
-
     }
 }

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

@@ -85,14 +85,14 @@ public class GridColspans extends AbstractTestUI {
             if (column != null) {
                 grid.removeColumn(column);
             } else {
-                grid.addColumn(Person::getFirstName).setId("firstName").setCaption("First name");
+                grid.addColumn(Person::getFirstName).setId("firstName")
+                        .setCaption("First name");
             }
         }));
 
-        addComponent(new Button("Change column order", event -> {
-            grid.setColumnOrder(grid.getColumn("ageColumn"),
-                    grid.getColumn("firstName"));
-        }));
+        addComponent(new Button("Change column order",
+                event -> grid.setColumnOrder(grid.getColumn("ageColumn"),
+                        grid.getColumn("firstName"))));
     }
 
     @Override

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

@@ -63,7 +63,6 @@ public class GridColumnWidthsWithoutData extends AbstractTestUI {
             items.clear();
             provider.refreshAll();
         }));
-
     }
 
     private void replaceGrid(Grid<Person> newGrid) {

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

@@ -75,7 +75,6 @@ public class GridDetailsLayoutExpand extends SimpleGridUI {
             final Person itemId = event.getItem();
             grid.setDetailsVisible(itemId, !grid.isDetailsVisible(itemId));
         });
-
     }
 
     @Override

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

@@ -115,10 +115,9 @@ public class GridHeaderFooterComponents extends AbstractTestUIWithLog {
         TextField filterField = new TextField();
         filterField.setWidth("8em");
         filterField.setValue("Filter: " + pid);
-        filterField.addValueChangeListener(listener -> {
-            log("value change for field in " + pid + " to "
-                    + listener.getValue());
-        });
+        filterField.addValueChangeListener(
+                listener -> log("value change for field in " + pid + " to "
+                        + listener.getValue()));
         return filterField;
     }
 

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

@@ -36,10 +36,10 @@ public class GridResizeHiddenColumn extends GridEditorUI {
 
         addComponent(grid);
 
-        grid.addColumnResizeListener(event -> {
-            log(String.format("Column resized: id=%s, width=%s",
-                    event.getColumn().getId(), event.getColumn().getWidth()));
-        });
+        grid.addColumnResizeListener(
+                event -> log(String.format("Column resized: id=%s, width=%s",
+                        event.getColumn().getId(),
+                        event.getColumn().getWidth())));
     }
 
     @Override

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

@@ -46,9 +46,8 @@ public class GridRowHeightChange extends AbstractReindeerTestUI {
                 "Theme selector", themes);
         themeSelector.setSelectedItem("reindeer");
         themeSelector.setEmptySelectionAllowed(false);
-        themeSelector.addValueChangeListener(event -> {
-            setTheme(event.getValue());
-        });
+        themeSelector
+                .addValueChangeListener(event -> setTheme(event.getValue()));
 
         VerticalLayout layout = new VerticalLayout();
         layout.setSpacing(true);

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

@@ -46,7 +46,6 @@ public class GridScrollToLineWhileResizing extends AbstractReindeerTestUI {
         });
 
         vsp.setFirstComponent(grid);
-
     }
 
     @Override

uitest/src/main/java/com/vaadin/tests/components/grid/basics/GridBasics.java

@@ -378,10 +378,10 @@ public class GridBasics extends AbstractTestUIWithLog {
                 3.67, 4.00, 4.33, 4.67)
                 .forEach(d -> addGridMethodMenu(heightByRows,
                         df.format(d) + " rows", d, grid::setHeightByRows));
-        sizeMenu.addItem("HeightMode Row", item -> {
-            grid.setHeightMode(
-                    item.isChecked() ? HeightMode.ROW : HeightMode.CSS);
-        }).setCheckable(true);
+        sizeMenu.addItem("HeightMode Row",
+                item -> grid.setHeightMode(
+                        item.isChecked() ? HeightMode.ROW : HeightMode.CSS))
+                .setCheckable(true);
 
         MenuItem heightMenu = sizeMenu.addItem("Height", null);
         Stream.of(50, 100, 200, 400).map(i -> i + "px").forEach(
@@ -514,7 +514,8 @@ public class GridBasics extends AbstractTestUIWithLog {
                 sg -> grid.getColumns().forEach(c -> c.setStyleGenerator(t -> {
                     if (t.getRowNumber() % 4 == 1) {
                         return null;
-                    } else if (t.getRowNumber() % 4 == 3
+                    }
+                    if (t.getRowNumber() % 4 == 3
                             && c.getCaption().equals("Column 1")) {
                         return null;
                     }
@@ -539,9 +540,8 @@ public class GridBasics extends AbstractTestUIWithLog {
                 grid.getSelectionModel().select(item);
             }
         });
-        rowMenu.addItem("Deselect all", menuItem -> {
-            grid.getSelectionModel().deselectAll();
-        });
+        rowMenu.addItem("Deselect all",
+                menuItem -> grid.getSelectionModel().deselectAll());
 
         MenuItem rowHeight = rowMenu.addItem("Body Row Height", null);
         Stream.of(-1, 20, 50, 100).forEach(i -> rowHeight.addItem("" + i,
@@ -559,9 +559,7 @@ public class GridBasics extends AbstractTestUIWithLog {
                             .addSingleSelectionListener(this::onSingleSelect);
             grid.asSingleSelect().setReadOnly(isUserSelectionDisallowed);
         });
-        selectionModelItem.addItem("multi", menuItem -> {
-            switchToMultiSelect();
-        });
+        selectionModelItem.addItem("multi", menuItem -> switchToMultiSelect());
         selectionModelItem.addItem("none", menuItem -> {
             selectionListenerRegistration.remove();
             grid.setSelectionMode(SelectionMode.NONE);
@@ -629,24 +627,18 @@ public class GridBasics extends AbstractTestUIWithLog {
                 row.getCell(column).setText("Header cell " + i++);
             }
         });
-        headerMenu.addItem("Remove first header row", menuItem -> {
-            grid.removeHeaderRow(0);
-        });
-        headerMenu.addItem("Set first row as default", menuItem -> {
-            grid.setDefaultHeaderRow(grid.getHeaderRow(0));
-        });
-        headerMenu.addItem("Set no default row", menuItem -> {
-            grid.setDefaultHeaderRow(null);
-        });
-        headerMenu.addItem("Merge Header Cells [0,0..1]", menuItem -> {
-            mergeHeaderСells(0, "0+1", 0, 1);
-        });
-        headerMenu.addItem("Merge Header Cells [1,1..3]", menuItem -> {
-            mergeHeaderСells(1, "1+2+3", 1, 2, 3);
-        });
-        headerMenu.addItem("Merge Header Cells [0,6..7]", menuItem -> {
-            mergeHeaderСells(0, "6+7", 6, 7);
-        });
+        headerMenu.addItem("Remove first header row",
+                menuItem -> grid.removeHeaderRow(0));
+        headerMenu.addItem("Set first row as default",
+                menuItem -> grid.setDefaultHeaderRow(grid.getHeaderRow(0)));
+        headerMenu.addItem("Set no default row",
+                menuItem -> grid.setDefaultHeaderRow(null));
+        headerMenu.addItem("Merge Header Cells [0,0..1]",
+                menuItem -> mergeHeaderСells(0, "0+1", 0, 1));
+        headerMenu.addItem("Merge Header Cells [1,1..3]",
+                menuItem -> mergeHeaderСells(1, "1+2+3", 1, 2, 3));
+        headerMenu.addItem("Merge Header Cells [0,6..7]",
+                menuItem -> mergeHeaderСells(0, "6+7", 6, 7));
 
         MenuItem rowHeight = headerMenu.addItem("Header Row Height", null);
         Stream.of(-1, 20, 50, 100).forEach(i -> rowHeight.addItem("" + i,
@@ -702,18 +694,14 @@ public class GridBasics extends AbstractTestUIWithLog {
                 row.getCell(column).setText("Footer cell " + i++);
             }
         });
-        footerMenu.addItem("Remove first footer row", menuItem -> {
-            grid.removeFooterRow(0);
-        });
-        footerMenu.addItem("Merge Footer Cells [0,0..1]", menuItem -> {
-            mergeFooterСells(0, "0+1", 0, 1);
-        });
-        footerMenu.addItem("Merge Footer Cells [1,1..3]", menuItem -> {
-            mergeFooterСells(1, "1+2+3", 1, 2, 3);
-        });
-        footerMenu.addItem("Merge Footer Cells [0,6..7]", menuItem -> {
-            mergeFooterСells(0, "6+7", 6, 7);
-        });
+        footerMenu.addItem("Remove first footer row",
+                menuItem -> grid.removeFooterRow(0));
+        footerMenu.addItem("Merge Footer Cells [0,0..1]",
+                menuItem -> mergeFooterСells(0, "0+1", 0, 1));
+        footerMenu.addItem("Merge Footer Cells [1,1..3]",
+                menuItem -> mergeFooterСells(1, "1+2+3", 1, 2, 3));
+        footerMenu.addItem("Merge Footer Cells [0,6..7]",
+                menuItem -> mergeFooterСells(0, "6+7", 6, 7));
 
         MenuItem rowHeight = footerMenu.addItem("Footer Row Height", null);
         Stream.of(-1, 20, 50, 100).forEach(i -> rowHeight.addItem("" + i,

uitest/src/main/java/com/vaadin/tests/components/gridlayout/GridLayoutWithLabel.java

@@ -16,9 +16,8 @@ public class GridLayoutWithLabel extends AbstractTestUI {
         layout.addComponent(new Label("This is the label"), 0, 0);
 
         CheckBox cb = new CheckBox("Unchecked");
-        cb.addValueChangeListener(evt -> {
-            cb.setCaption(evt.getValue() ? "Checked" : "Unchecked");
-        });
+        cb.addValueChangeListener(
+                evt -> cb.setCaption(evt.getValue() ? "Checked" : "Unchecked"));
 
         layout.addComponent(cb, 1, 0);
 

uitest/src/main/java/com/vaadin/tests/components/javascriptcomponent/DuplicateJavascriptDependencies.java

@@ -37,9 +37,8 @@ public class DuplicateJavascriptDependencies extends AbstractTestUIWithLog {
 
     @Override
     protected void setup(VaadinRequest request) {
-        addComponent(new Button("Test", e -> {
-            addComponent(new ResultLabel("It works"));
-        }));
+        addComponent(new Button("Test",
+                e -> addComponent(new ResultLabel("It works"))));
     }
 
 }

uitest/src/main/java/com/vaadin/tests/components/loginform/LoginFormUI.java

@@ -26,10 +26,9 @@ public class LoginFormUI extends AbstractReindeerTestUI {
         getPasswordCaption().ifPresent(loginForm::setPasswordCaption);
         getLoginCaption().ifPresent(loginForm::setLoginButtonCaption);
         updateCaption();
-        loginForm.addLoginListener(event -> {
-            login(event.getSource(), event.getLoginParameter("username"),
-                    event.getLoginParameter("password"));
-        });
+        loginForm.addLoginListener(event -> login(event.getSource(),
+                event.getLoginParameter("username"),
+                event.getLoginParameter("password")));
 
         loginFormLayout.addComponent(loginForm);
 

uitest/src/main/java/com/vaadin/tests/components/richtextarea/ConfigurableRichTextAreaUI.java

@@ -14,9 +14,8 @@ public class ConfigurableRichTextAreaUI
     @Override
     protected void createActions() {
         super.createActions();
-        createClickAction("Select all", CATEGORY_FEATURES, (rta, a, b) -> {
-            rta.selectAll();
-        }, null);
+        createClickAction("Select all", CATEGORY_FEATURES,
+                (rta, a, b) -> rta.selectAll(), null);
     }
 
 }

uitest/src/main/java/com/vaadin/tests/components/textfield/TextFieldEmptyingPrompt.java

@@ -47,9 +47,8 @@ public class TextFieldEmptyingPrompt extends AbstractReindeerTestUI {
         addComponent(label);
 
         textField.setPlaceholder(RANDOM_PROMPT);
-        textField.addValueChangeListener(listener -> {
-            label.setValue("Textfield value: " + listener.getValue());
-        });
+        textField.addValueChangeListener(listener -> label
+                .setValue("Textfield value: " + listener.getValue()));
         addComponent(textField);
 
         Button button = new Button("Click To Remove Prompt");

uitest/src/main/java/com/vaadin/tests/components/tree/TreeBasicFeatures.java

@@ -149,12 +149,10 @@ public class TreeBasicFeatures extends AbstractTestUIWithLog {
     }
 
     private void createDescriptionMenu(MenuItem descriptionMenu) {
-        descriptionMenu.addItem("No Description", menu -> {
-            tree.setItemDescriptionGenerator(t -> null);
-        });
-        descriptionMenu.addItem("String.valueOf", menu -> {
-            tree.setItemDescriptionGenerator(String::valueOf);
-        });
+        descriptionMenu.addItem("No Description",
+                menu -> tree.setItemDescriptionGenerator(t -> null));
+        descriptionMenu.addItem("String.valueOf",
+                menu -> tree.setItemDescriptionGenerator(String::valueOf));
     }
 
     private void createContentModeMenu(MenuItem contentModeMenu) {

uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridAriaRowcount.java

@@ -35,19 +35,22 @@ public class TreeGridAriaRowcount extends AbstractTestUI {
         addComponent(grid);
 
         addComponent(new Button("addFooter", event -> grid.addFooterRowAt(0)));
-        addComponent(new Button("removeFooter", event -> grid.removeFooterRow(0)));
+        addComponent(
+                new Button("removeFooter", event -> grid.removeFooterRow(0)));
 
         addComponent(new Button("addHeader", event -> grid.addHeaderRowAt(1)));
-        addComponent(new Button("removeHeader", event -> grid.removeHeaderRow(1)));
+        addComponent(
+                new Button("removeHeader", event -> grid.removeHeaderRow(1)));
 
-        addComponent(new Button("setItemsTo3", event -> grid.setItems("a", "b", "c")));
-        addComponent(new Button("setItemsTo6", event -> grid.setItems("a", "b", "c", "d", "e", "f")));
+        addComponent(new Button("setItemsTo3",
+                event -> grid.setItems("a", "b", "c")));
+        addComponent(new Button("setItemsTo6",
+                event -> grid.setItems("a", "b", "c", "d", "e", "f")));
 
         addComponent(new Button("updateAll", event -> {
             grid.addFooterRowAt(0);
             grid.addHeaderRowAt(0);
             grid.setItems("a", "b", "c", "d");
         }));
-
     }
 }

uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridDragAndDrop.java

@@ -24,7 +24,7 @@ public class TreeGridDragAndDrop extends AbstractTestUIWithLog {
                 .setId("string");
         grid.addColumn(HierarchicalTestBean::getDepth).setCaption("Depth")
                 .setId("depth").setDescriptionGenerator(
-                t -> "Hierarchy depth: " + t.getDepth());
+                        t -> "Hierarchy depth: " + t.getDepth());
         grid.addColumn(HierarchicalTestBean::getIndex)
                 .setCaption("Index on this depth").setId("index");
         grid.setHierarchyColumn("string");
@@ -37,11 +37,9 @@ public class TreeGridDragAndDrop extends AbstractTestUIWithLog {
         TreeGridDropTarget<HierarchicalTestBean> dropTarget = new TreeGridDropTarget<>(
                 grid, DropMode.ON_TOP_OR_BETWEEN);
 
-        dropTarget.addTreeGridDropListener(event -> {
-            log("depth=" + event.getDropTargetRowDepth().orElse(null)
-                    + ", collapsed=" + event.isDropTargetRowCollapsed()
-                    .orElse(null));
-        });
+        dropTarget.addTreeGridDropListener(event -> log("depth="
+                + event.getDropTargetRowDepth().orElse(null) + ", collapsed="
+                + event.isDropTargetRowCollapsed().orElse(null)));
 
         addComponent(grid);
     }

uitest/src/main/java/com/vaadin/tests/components/treegrid/TreeGridInWindow.java

@@ -26,9 +26,8 @@ public class TreeGridInWindow extends AbstractTestUI {
 
         Window window = new Window("Window", treeGrid);
 
-        Button openWindow = new Button("Open window", event -> {
-            UI.getCurrent().addWindow(window);
-        });
+        Button openWindow = new Button("Open window",
+                event -> UI.getCurrent().addWindow(window));
 
         getLayout().addComponent(openWindow);
     }

uitest/src/main/java/com/vaadin/tests/data/DummyData.java

@@ -98,16 +98,13 @@ public class DummyData extends AbstractTestUIWithLog {
 
         HorizontalLayout controls = new HorizontalLayout();
         addComponent(controls);
-        controls.addComponent(new Button("Select Foo 20", e -> {
-            dummy.setValue("Foo " + 20);
-        }));
-        controls.addComponent(new Button("Reset data provider", e -> {
-            dummy.setDataProvider(new LoggingDataProvider(items));
-        }));
-        controls.addComponent(new Button("Remove all data", e -> {
-            dummy.setDataProvider(
-                    new LoggingDataProvider(Collections.emptyList()));
-        }));
+        controls.addComponent(
+                new Button("Select Foo 20", e -> dummy.setValue("Foo " + 20)));
+        controls.addComponent(new Button("Reset data provider",
+                e -> dummy.setDataProvider(new LoggingDataProvider(items))));
+        controls.addComponent(
+                new Button("Remove all data", e -> dummy.setDataProvider(
+                        new LoggingDataProvider(Collections.emptyList()))));
         addComponent(dummy);
     }
 }

uitest/src/main/java/com/vaadin/tests/data/GridRefreshWithGetId.java

@@ -36,9 +36,9 @@ public class GridRefreshWithGetId extends AbstractTestUI {
         }
 
         /**
-         * The class intentionally has strange {@code hashCode()} and {@code equals()}
-         * implementation to ensure if {@code Grid} relies on bean id rather than on
-         * bean hashcode/equals identification.
+         * The class intentionally has strange {@code hashCode()} and
+         * {@code equals()} implementation to ensure if {@code Grid} relies on
+         * bean id rather than on bean hashcode/equals identification.
          *
          * {@see Object.equals}
          */
@@ -58,9 +58,9 @@ public class GridRefreshWithGetId extends AbstractTestUI {
         }
 
         /**
-         * The class intentionally has strange {@code hashCode()} and {@code equals()}
-         * implementation to ensure if {@code Grid} relies on bean id rather than on
-         * bean hashcode/equals identification.
+         * The class intentionally has strange {@code hashCode()} and
+         * {@code equals()} implementation to ensure if {@code Grid} relies on
+         * bean id rather than on bean hashcode/equals identification.
          *
          * {@see Object.hashCode}
          */
@@ -94,9 +94,7 @@ public class GridRefreshWithGetId extends AbstractTestUI {
         grid.setDataProvider(dataProvider);
         addComponent(grid);
 
-        grid.addColumn(myObject -> {
-            return myObject.getName();
-        });
+        grid.addColumn(TestObject::getName);
 
         Button button = new Button("Change green to black");
         button.addClickListener(event1 -> {

uitest/src/main/java/com/vaadin/tests/dnd/DragAndDropCardShuffle.java

@@ -22,9 +22,9 @@ import com.vaadin.annotations.Theme;
 import com.vaadin.annotations.Widgetset;
 import com.vaadin.server.Page;
 import com.vaadin.server.VaadinRequest;
-import com.vaadin.shared.ui.dnd.criteria.ComparisonOperator;
 import com.vaadin.shared.ui.dnd.DropEffect;
 import com.vaadin.shared.ui.dnd.EffectAllowed;
+import com.vaadin.shared.ui.dnd.criteria.ComparisonOperator;
 import com.vaadin.tests.components.AbstractTestUIWithLog;
 import com.vaadin.ui.CheckBox;
 import com.vaadin.ui.HorizontalLayout;
@@ -126,15 +126,12 @@ public class DragAndDropCardShuffle extends AbstractTestUIWithLog {
         dragSource.setPayload("card_value", cardValue);
 
         // Add listeners
-        dragSource.addDragStartListener(event -> {
-            log(event.getComponent().getValue() + " dragstart, effectsAllowed="
-                    + event.getEffectAllowed());
-        });
+        dragSource.addDragStartListener(e -> log(
+                e.getComponent().getValue() + " dragstart, effectsAllowed="
+                        + e.getEffectAllowed()));
 
-        dragSource.addDragEndListener(event -> {
-            log(event.getComponent().getValue() + " dragend, dropEffect="
-                    + event.getDropEffect());
-        });
+        dragSource.addDragEndListener(e -> log(e.getComponent().getValue()
+                        + " dragend, dropEffect=" + e.getDropEffect()));
 
         sources.add(dragSource);
     }
@@ -145,28 +142,27 @@ public class DragAndDropCardShuffle extends AbstractTestUIWithLog {
                 target);
 
         // Cards can be dropped onto others with smaller value
-        dropTarget.setDropCriterion("card_value", ComparisonOperator.SMALLER_THAN,
-                cardValue);
+        dropTarget.setDropCriterion("card_value",
+                ComparisonOperator.SMALLER_THAN, cardValue);
 
         // Add listener
-        dropTarget.addDropListener(event -> {
-            event.getDragSourceExtension().ifPresent(dragSource -> {
-                if (dragSource.getParent() instanceof Label) {
-                    Label source = (Label) dragSource.getParent();
-
-                    // Swap source and target components
-                    desk.replaceComponent(target, source);
-
-                    log(event.getComponent().getValue() + " drop received "
-                            + source.getValue() + ", dropEffect="
-                            + event.getDropEffect() + ", mouseEventDetails="
-                            + event.getMouseEventDetails());
-                } else {
-                    log(event.getComponent().getValue()
-                            + " drop received something else than card");
-                }
-            });
-        });
+        dropTarget.addDropListener(event -> event.getDragSourceExtension()
+                .ifPresent(dragSource -> {
+                    if (dragSource.getParent() instanceof Label) {
+                        Label source = (Label) dragSource.getParent();
+
+                        // Swap source and target components
+                        desk.replaceComponent(target, source);
+
+                        log(event.getComponent().getValue() + " drop received "
+                                + source.getValue() + ", dropEffect="
+                                + event.getDropEffect() + ", mouseEventDetails="
+                                + event.getMouseEventDetails());
+                    } else {
+                        log(event.getComponent().getValue()
+                                + " drop received something else than card");
+                    }
+                }));
 
         targets.add(dropTarget);
     }

uitest/src/main/java/com/vaadin/tests/dnd/Html5FileDragAndDropUpload.java

@@ -39,69 +39,74 @@ public class Html5FileDragAndDropUpload extends AbstractTestUIWithLog {
     @Override
     protected void setup(VaadinRequest request) {
 
-        Grid<FileParameters> grid = new Grid<>("Drop files or text on the Grid");
+        Grid<FileParameters> grid = new Grid<>(
+                "Drop files or text on the Grid");
         grid.addColumn(FileParameters::getName).setCaption("File name");
         grid.addColumn(FileParameters::getSize).setCaption("File size");
         grid.addColumn(FileParameters::getMime).setCaption("Mime type");
 
         List<FileParameters> gridItems = new ArrayList<>();
 
-        new FileDropTarget<Grid<FileParameters>>(grid, event -> {
-            event.getFiles().forEach(html5File -> {
-                if (html5File.getFileSize() > FILE_SIZE_LIMIT) {
-                    Notification.show(html5File.getFileName()
-                            + " is too large (max 5 MB)");
-                    return;
-                }
-
-                html5File.setStreamVariable(new StreamVariable() {
-                    @Override
-                    public OutputStream getOutputStream() {
-                        return new OutputStream() {
-                            @Override
-                            public void write(int b) throws IOException {
-                                // NOP
-                            }
-                        };
+        new FileDropTarget<Grid<FileParameters>>(grid,
+                event -> event.getFiles().forEach(html5File -> {
+                    if (html5File.getFileSize() > FILE_SIZE_LIMIT) {
+                        Notification.show(html5File.getFileName()
+                                + " is too large (max 5 MB)");
+                        return;
                     }
 
-                    @Override
-                    public boolean listenProgress() {
-                        return true;
-                    }
-
-                    @Override
-                    public void onProgress(StreamingProgressEvent event) {
-                        log("Progress, bytesReceived=" + event
-                                .getBytesReceived());
-                    }
-
-                    @Override
-                    public void streamingStarted(StreamingStartEvent event) {
-                        log("Stream started, fileName=" + event.getFileName());
-                    }
-
-                    @Override
-                    public void streamingFinished(StreamingEndEvent event) {
-                        gridItems.add(new FileParameters(event.getFileName(),
-                                event.getContentLength(), event.getMimeType()));
-                        grid.setItems(gridItems);
-
-                        log("Stream finished, fileName=" + event.getFileName());
-                    }
-
-                    @Override
-                    public void streamingFailed(StreamingErrorEvent event) {
-                        log("Stream failed, fileName=" + event.getFileName());
-                    }
-
-                    @Override
-                    public boolean isInterrupted() {
-                        return false;
-                    }
-                });
-            });
-        });
+                    html5File.setStreamVariable(new StreamVariable() {
+                        @Override
+                        public OutputStream getOutputStream() {
+                            return new OutputStream() {
+                                @Override
+                                public void write(int b) throws IOException {
+                                    // NOP
+                                }
+                            };
+                        }
+
+                        @Override
+                        public boolean listenProgress() {
+                            return true;
+                        }
+
+                        @Override
+                        public void onProgress(StreamingProgressEvent event) {
+                            log("Progress, bytesReceived="
+                                    + event.getBytesReceived());
+                        }
+
+                        @Override
+                        public void streamingStarted(
+                                StreamingStartEvent event) {
+                            log("Stream started, fileName="
+                                    + event.getFileName());
+                        }
+
+                        @Override
+                        public void streamingFinished(StreamingEndEvent event) {
+                            gridItems.add(new FileParameters(event.getFileName(),
+                                            event.getContentLength(),
+                                            event.getMimeType()));
+                            grid.setItems(gridItems);
+
+                            log("Stream finished, fileName="
+                                    + event.getFileName());
+                        }
+
+                        @Override
+                        public void streamingFailed(StreamingErrorEvent event) {
+                            log("Stream failed, fileName="
+                                    + event.getFileName());
+                        }
+
+                        @Override
+                        public boolean isInterrupted() {
+                            return false;
+                        }
+                    });
+                }));
 
         GridDropTarget<FileParameters> dropTarget = new GridDropTarget<>(grid,
                 DropMode.ON_TOP);

uitest/src/main/java/com/vaadin/tests/elements/ComponentElementGetValue.java

@@ -99,9 +99,8 @@ public class ComponentElementGetValue extends AbstractTestUI {
         components.add(new TwinColSelect<>("", createData()));
         components.forEach(c -> {
             c.select(TEST_STRING_VALUE);
-            c.addValueChangeListener(event -> {
-                valueChangeLabel.setValue(MULTI_SELECT_VALUE_CHANGE);
-            });
+            c.addValueChangeListener(event -> valueChangeLabel
+                    .setValue(MULTI_SELECT_VALUE_CHANGE));
             addComponent((Component) c);
         });
     }
@@ -118,9 +117,8 @@ public class ComponentElementGetValue extends AbstractTestUI {
             AbstractTextField field = fieldComponents[i];
             field.setValue(TEST_STRING_VALUE);
             String value = FIELD_VALUES[i];
-            field.addValueChangeListener(event -> {
-                valueChangeLabel.setValue(value);
-            });
+            field.addValueChangeListener(
+                    event -> valueChangeLabel.setValue(value));
             addComponent(field);
         }
 
@@ -135,9 +133,8 @@ public class ComponentElementGetValue extends AbstractTestUI {
         DateField df = new DateField();
         df.setDateFormat("yyyy-MM-dd");
         df.setValue(TEST_DATE_VALUE);
-        df.addValueChangeListener(event -> {
-            valueChangeLabel.setValue(DATEFIELD_VALUE_CHANGE);
-        });
+        df.addValueChangeListener(
+                event -> valueChangeLabel.setValue(DATEFIELD_VALUE_CHANGE));
         return df;
     }
 
@@ -151,9 +148,8 @@ public class ComponentElementGetValue extends AbstractTestUI {
     private CheckBox createCheckBox() {
         CheckBox cb = new CheckBox();
         cb.setValue(true);
-        cb.addValueChangeListener(event -> {
-            valueChangeLabel.setValue(CHECKBOX_VALUE_CHANGE);
-        });
+        cb.addValueChangeListener(
+                event -> valueChangeLabel.setValue(CHECKBOX_VALUE_CHANGE));
         return cb;
     }
 

uitest/src/main/java/com/vaadin/tests/elements/combobox/ComboBoxInputNotAllowed.java

@@ -27,9 +27,8 @@ public class ComboBoxInputNotAllowed extends AbstractTestUI {
     protected void setup(VaadinRequest request) {
         ComboBox<String> comboBox = new ComboBox<>("", ITEMS);
         comboBox.setTextInputAllowed(false);
-        comboBox.addValueChangeListener(e -> {
-            addComponent(new Label("Value is now: " + e.getValue()));
-        });
+        comboBox.addValueChangeListener(
+                e -> addComponent(new Label("Value is now: " + e.getValue())));
 
         addComponent(comboBox);
     }

uitest/src/main/java/com/vaadin/tests/elements/combobox/ComboBoxUI.java

@@ -49,9 +49,8 @@ public class ComboBoxUI extends AbstractTestUI {
         comboBox.setItemIconGenerator(item -> {
             if (item.equals("EUR")) {
                 return new ThemeResource("shared/img/spinner.gif");
-            } else {
-                return new ThemeResource("notfound.png");
             }
+            return new ThemeResource("notfound.png");
         });
         addComponent(comboBox);
     }

uitest/src/main/java/com/vaadin/tests/elements/combobox/SelectByText.java

@@ -53,11 +53,8 @@ public class SelectByText extends AbstractTestUI {
         combobox.setItems(options);
 
         layout.addComponent(combobox);
-        combobox.addValueChangeListener(e -> {
-            layout.addComponent(
-                    new Label("Value is now '" + e.getValue() + "'"));
-        });
-
+        combobox.addValueChangeListener(e -> layout.addComponent(
+                new Label("Value is now '" + e.getValue() + "'")));
     }
 
     @Override

uitest/src/main/java/com/vaadin/tests/elements/grid/GridUI.java

@@ -26,10 +26,8 @@ public class GridUI extends AbstractTestUI {
         row.getCell(column).setText("extra row");
         grid.addColumn(Item::getBar).setCaption("bar");
 
-        grid.setDetailsGenerator(item -> {
-            return new Label(
-                    "Foo = " + item.getFoo() + " Bar = " + item.getBar());
-        });
+        grid.setDetailsGenerator(item -> new Label(
+                "Foo = " + item.getFoo() + " Bar = " + item.getBar()));
         grid.addItemClickListener(event -> {
             if (event.getMouseEventDetails().isDoubleClick()) {
                 grid.setDetailsVisible(event.getItem(),

uitest/src/main/java/com/vaadin/tests/layouts/gridlayout/GridLayoutCaptionOnBottomAlignedComponent.java

@@ -21,9 +21,8 @@ public class GridLayoutCaptionOnBottomAlignedComponent extends AbstractTestUI {
 
         addComponent(layout);
 
-        Button realign = new Button("Realign", evt -> {
-            layout.setComponentAlignment(component, Alignment.TOP_LEFT);
-        });
+        Button realign = new Button("Realign", evt -> layout
+                .setComponentAlignment(component, Alignment.TOP_LEFT));
         addComponent(realign);
     }
 }

uitest/src/main/java/com/vaadin/tests/navigator/DelayedViewLeaveConfirmation.java

@@ -52,16 +52,13 @@ public class DelayedViewLeaveConfirmation extends AbstractTestUI {
             input = new TextField("Enter a value");
             input.setId("input");
             Button navigateAway = new Button("Navigate to the other view",
-                    e -> {
-                        getUI().getNavigator().navigateTo("other");
-                    });
-            Button logout = new Button("Simulate logout", e -> {
-                getUI().getNavigator().runAfterLeaveConfirmation(() -> {
-                    removeAllComponents();
-                    addComponent(new Label("You have been logged out"));
-                    getUI().getPage().setUriFragment("", false);
-                });
-            });
+                    e -> getUI().getNavigator().navigateTo("other"));
+            Button logout = new Button("Simulate logout", e -> getUI()
+                    .getNavigator().runAfterLeaveConfirmation(() -> {
+                        removeAllComponents();
+                        addComponent(new Label("You have been logged out"));
+                        getUI().getPage().setUriFragment("", false);
+                    }));
             navigateAway.setId("navigateAway");
             logout.setId("logout");
             addComponents(saved, input, navigateAway, logout);
@@ -95,9 +92,7 @@ public class DelayedViewLeaveConfirmation extends AbstractTestUI {
                 action.run();
             });
             leave.setId("leave");
-            Button stay = new Button("NO, STAY!", e -> {
-                close();
-            });
+            Button stay = new Button("NO, STAY!", e -> close());
             stay.setId("stay");
             layout.addComponents(new HorizontalLayout(leave, stay));
             setContent(layout);

uitest/src/main/java/com/vaadin/tests/resources/FrontendLaterLoadedResourceUI.java

@@ -32,10 +32,8 @@ public class FrontendLaterLoadedResourceUI extends AbstractTestUIWithLog {
     @Override
     protected void setup(VaadinRequest request) {
         Button b = new MyButton();
-        b.addClickListener(e -> {
-            getPage().getJavaScript()
-                    .execute("document.body.innerHTML=window.jsFile;\n");
-        });
+        b.addClickListener(e -> getPage().getJavaScript()
+                .execute("document.body.innerHTML=window.jsFile;\n"));
         addComponent(b);
     }
 

uitest/src/test/java/com/vaadin/tests/components/tree/TreeBasicFeaturesTest.java

@@ -21,21 +21,18 @@ import com.vaadin.tests.tb3.MultiBrowserTest;
 
 public class TreeBasicFeaturesTest extends MultiBrowserTest {
 
-    private static final Predicate<TestBenchElement> THEME_RESOURCE = e -> {
-        return e.isElementPresent(By.tagName("img"))
-                && e.findElement(By.tagName("img")).getAttribute("src")
-                        .contains("bullet.png");
-    };
-    private static final Predicate<TestBenchElement> VAADIN_ICON = e -> {
-        return e.isElementPresent(By.className("v-icon"))
-                && e.findElement(By.className("v-icon")).getAttribute("class")
-                        .contains("Vaadin-Icons");
-    };
-    private static final Predicate<TestBenchElement> CLASS_RESOURCE = e -> {
-        return e.isElementPresent(By.tagName("img"))
-                && e.findElement(By.tagName("img")).getAttribute("src")
-                        .contains("m.gif");
-    };
+    private static final Predicate<TestBenchElement> THEME_RESOURCE =
+            e -> e.isElementPresent(By.tagName("img"))
+            && e.findElement(By.tagName("img")).getAttribute("src")
+                    .contains("bullet.png");
+    private static final Predicate<TestBenchElement> VAADIN_ICON =
+            e -> e.isElementPresent(By.className("v-icon"))
+            && e.findElement(By.className("v-icon")).getAttribute("class")
+                    .contains("Vaadin-Icons");
+    private static final Predicate<TestBenchElement> CLASS_RESOURCE =
+            e -> e.isElementPresent(By.tagName("img"))
+            && e.findElement(By.tagName("img")).getAttribute("src")
+                    .contains("m.gif");
 
     @Before
     public void before() {