Use enhanced for loop instead of Iterator. (#10100)

49 files changed, 212 insertions, 395 deletions

diff --git a/client/src/main/java/com/vaadin/client/componentlocator/LegacyLocatorStrategy.java b/client/src/main/java/com/vaadin/client/componentlocator/LegacyLocatorStrategy.java
index 76360eb40d..d2c818f2f5 100644
--- a/client/src/main/java/com/vaadin/client/componentlocator/LegacyLocatorStrategy.java
+++ b/client/src/main/java/com/vaadin/client/componentlocator/LegacyLocatorStrategy.java
@@ -16,7 +16,6 @@
 package com.vaadin.client.componentlocator;
 
 import java.util.ArrayList;
-import java.util.Iterator;
 import java.util.List;
 
 import com.google.gwt.core.client.JavaScriptObject;
@@ -470,10 +469,8 @@ public class LegacyLocatorStrategy implements LocatorStrategy {
             return null;
         }
 
-        Iterator<?> i = ((Iterable<?>) parent).iterator();
         int pos = 0;
-        while (i.hasNext()) {
-            Object child = i.next();
+        for (Object child : (Iterable<?>) parent) {
             if (child == w) {
                 return basePath + PARENTCHILD_SEPARATOR + simpleName + "[" + pos
                         + "]";
@@ -638,7 +635,7 @@ public class LegacyLocatorStrategy implements LocatorStrategy {
                 }
 
                 // Locate the child
-                Iterator<? extends Widget> iterator;
+                Iterable<? extends Widget> iterable;
 
                 /*
                  * VWindow and VContextMenu workarounds for backwards
@@ -652,19 +649,18 @@ public class LegacyLocatorStrategy implements LocatorStrategy {
                     for (WindowConnector wc : windows) {
                         windowWidgets.add(wc.getWidget());
                     }
-                    iterator = windowWidgets.iterator();
+                    iterable = windowWidgets;
                 } else if (widgetClassName.equals("VContextMenu")) {
                     return client.getContextMenu();
                 } else {
-                    iterator = (Iterator<? extends Widget>) parent.iterator();
+                    iterable = (Iterable<? extends Widget>) parent;
                 }
 
                 boolean ok = false;
 
                 // Find the widgetPosition:th child of type "widgetClassName"
-                while (iterator.hasNext()) {
+                for (Widget child : iterable) {
 
-                    Widget child = iterator.next();
                     String simpleName2 = Util.getSimpleName(child);
 
                     if (!widgetClassName.equals(simpleName2)
diff --git a/client/src/main/java/com/vaadin/client/debug/internal/HierarchyPanel.java b/client/src/main/java/com/vaadin/client/debug/internal/HierarchyPanel.java
index e70da1188c..1172704ba0 100644
--- a/client/src/main/java/com/vaadin/client/debug/internal/HierarchyPanel.java
+++ b/client/src/main/java/com/vaadin/client/debug/internal/HierarchyPanel.java
@@ -16,7 +16,6 @@
 package com.vaadin.client.debug.internal;
 
 import java.util.ArrayList;
-import java.util.Iterator;
 import java.util.List;
 
 import com.google.gwt.event.dom.client.ClickEvent;
@@ -50,9 +49,8 @@ public class HierarchyPanel extends FlowPanel {
     public void update() {
         // Try to keep track of currently open nodes and reopen them
         FastStringSet openNodes = FastStringSet.create();
-        Iterator<Widget> it = iterator();
-        while (it.hasNext()) {
-            collectOpenNodes(it.next(), openNodes);
+        for (Widget widget : this) {
+            collectOpenNodes(widget, openNodes);
         }
 
         clear();
@@ -90,9 +88,8 @@ public class HierarchyPanel extends FlowPanel {
             }
         }
         if (widget instanceof HasWidgets) {
-            Iterator<Widget> it = ((HasWidgets) widget).iterator();
-            while (it.hasNext()) {
-                collectOpenNodes(it.next(), openNodes);
+            for (Widget child : (HasWidgets) widget) {
+                collectOpenNodes(child, openNodes);
             }
         }
     }
diff --git a/client/src/main/java/com/vaadin/client/ui/ShortcutActionHandler.java b/client/src/main/java/com/vaadin/client/ui/ShortcutActionHandler.java
index d85643099c..26d3fd7be0 100644
--- a/client/src/main/java/com/vaadin/client/ui/ShortcutActionHandler.java
+++ b/client/src/main/java/com/vaadin/client/ui/ShortcutActionHandler.java
@@ -18,7 +18,6 @@ package com.vaadin.client.ui;
 
 import java.util.ArrayList;
 import java.util.Iterator;
-import java.util.List;
 
 import com.google.gwt.core.client.Scheduler;
 import com.google.gwt.dom.client.Element;
@@ -59,7 +58,7 @@ public class ShortcutActionHandler {
         ShortcutActionHandler getShortcutActionHandler();
     }
 
-    private final List<ShortcutAction> actions = new ArrayList<>();
+    private final ArrayList<ShortcutAction> actions = new ArrayList<>();
     private ApplicationConnection client;
     private String paintableId;
 
@@ -101,17 +100,15 @@ public class ShortcutActionHandler {
 
     public void handleKeyboardEvent(final Event event,
             ComponentConnector target) {
-        final int modifiers = KeyboardListenerCollection
-                .getKeyboardModifiers(event);
         final char keyCode = (char) DOM.eventGetKeyCode(event);
         if (keyCode == 0) {
             return;
         }
+        final int modifiers = KeyboardListenerCollection
+                .getKeyboardModifiers(event);
         final ShortcutKeyCombination kc = new ShortcutKeyCombination(keyCode,
                 modifiers);
-        final Iterator<ShortcutAction> it = actions.iterator();
-        while (it.hasNext()) {
-            final ShortcutAction a = it.next();
+        for (final ShortcutAction a : actions) {
             if (a.getShortcutCombination().equals(kc)) {
                 fireAction(event, a, target);
                 break;
diff --git a/client/src/main/java/com/vaadin/client/ui/VAbstractCalendarPanel.java b/client/src/main/java/com/vaadin/client/ui/VAbstractCalendarPanel.java
index b1e5843125..da5d320c8d 100644
--- a/client/src/main/java/com/vaadin/client/ui/VAbstractCalendarPanel.java
+++ b/client/src/main/java/com/vaadin/client/ui/VAbstractCalendarPanel.java
@@ -17,7 +17,6 @@
 package com.vaadin.client.ui;
 
 import java.util.Date;
-import java.util.Iterator;
 import java.util.List;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
@@ -530,7 +529,8 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
         updateControlButtonRangeStyles(needsMonth);
 
         final String monthName = needsMonth
-                ? getDateTimeService().getMonth(displayedMonth.getMonth()) : "";
+                ? getDateTimeService().getMonth(displayedMonth.getMonth())
+                : "";
         final int year = displayedMonth.getYear() + 1900;
 
         getFlexCellFormatter().setStyleName(0, 2,
@@ -1485,8 +1485,8 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
 
     /**
      * Returns the reset key which will reset the calendar to the previous
-     * selection. By default this is backspace but it can be overridden to change
-     * the key to whatever you want.
+     * selection. By default this is backspace but it can be overridden to
+     * change the key to whatever you want.
      *
      * @return
      */
@@ -1926,9 +1926,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
                     .parseInt(subPart.substring(SUBPART_DAY.length()));
             Date date = new Date(displayedMonth.getYear(),
                     displayedMonth.getMonth(), dayOfMonth);
-            Iterator<Widget> iter = days.iterator();
-            while (iter.hasNext()) {
-                Widget w = iter.next();
+            for (Widget w : days) {
                 if (w instanceof VAbstractCalendarPanel.Day) {
                     Day day = (Day) w;
                     if (day.getDate().equals(date)) {
@@ -1994,7 +1992,8 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
 
         private void setLabel() {
             if (getDateField() instanceof VAbstractPopupCalendar) {
-                ((VAbstractPopupCalendar<?, ?>) getDateField()).setFocusedDate(this);
+                ((VAbstractPopupCalendar<?, ?>) getDateField())
+                        .setFocusedDate(this);
             }
         }
     }
diff --git a/client/src/main/java/com/vaadin/client/ui/VComboBox.java b/client/src/main/java/com/vaadin/client/ui/VComboBox.java
index 9ae8115d8b..69d9e39529 100644
--- a/client/src/main/java/com/vaadin/client/ui/VComboBox.java
+++ b/client/src/main/java/com/vaadin/client/ui/VComboBox.java
@@ -20,7 +20,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Date;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 
@@ -1089,10 +1088,8 @@ public class VComboBox extends Composite implements Field, KeyDownHandler,
             }
 
             clearItems();
-            final Iterator<ComboBoxSuggestion> it = suggestions.iterator();
             boolean isFirstIteration = true;
-            while (it.hasNext()) {
-                final ComboBoxSuggestion suggestion = it.next();
+            for (final ComboBoxSuggestion suggestion : suggestions) {
                 final MenuItem mi = new MenuItem(suggestion.getDisplayString(),
                         true, suggestion);
                 String style = suggestion.getStyle();
diff --git a/client/src/main/java/com/vaadin/client/widgets/ChildFocusAwareFlowPanel.java b/client/src/main/java/com/vaadin/client/widgets/ChildFocusAwareFlowPanel.java
index 19ee7b8a21..0d430f8c7f 100644
--- a/client/src/main/java/com/vaadin/client/widgets/ChildFocusAwareFlowPanel.java
+++ b/client/src/main/java/com/vaadin/client/widgets/ChildFocusAwareFlowPanel.java
@@ -144,11 +144,11 @@ public class ChildFocusAwareFlowPanel extends FocusableFlowPanel
 
     @Override
     public void focus() {
-        Iterator<Widget> iterator = iterator();
-        if (iterator.hasNext()) {
-            Widget widget = iterator.next();
-            if (widget instanceof Focusable) {
-                ((Focusable) widget).setFocus(true);
+        Iterator<Widget> it = iterator();
+        if (it.hasNext()) {
+            Widget child = it.next();
+            if (child instanceof Focusable) {
+                ((Focusable) child).setFocus(true);
             }
         }
     }
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VCalendarPanel.java b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VCalendarPanel.java
index 2c2841042d..bb4acd257b 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VCalendarPanel.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VCalendarPanel.java
@@ -17,7 +17,6 @@
 package com.vaadin.v7.client.ui;
 
 import java.util.Date;
-import java.util.Iterator;
 
 import com.google.gwt.aria.client.Roles;
 import com.google.gwt.aria.client.SelectedValue;
@@ -450,7 +449,8 @@ public class VCalendarPanel extends FocusableFlexTable implements
         updateControlButtonRangeStyles(needsMonth);
 
         final String monthName = needsMonth
-                ? getDateTimeService().getMonth(displayedMonth.getMonth()) : "";
+                ? getDateTimeService().getMonth(displayedMonth.getMonth())
+                : "";
         final int year = displayedMonth.getYear() + 1900;
 
         getFlexCellFormatter().setStyleName(0, 2,
@@ -1404,8 +1404,8 @@ public class VCalendarPanel extends FocusableFlexTable implements
 
     /**
      * Returns the reset key which will reset the calendar to the previous
-     * selection. By default this is backspace but it can be overridden to change
-     * the key to whatever you want.
+     * selection. By default this is backspace but it can be overridden to
+     * change the key to whatever you want.
      *
      * @return
      */
@@ -2138,9 +2138,7 @@ public class VCalendarPanel extends FocusableFlexTable implements
                     .parseInt(subPart.substring(SUBPART_DAY.length()));
             Date date = new Date(displayedMonth.getYear(),
                     displayedMonth.getMonth(), dayOfMonth);
-            Iterator<Widget> iter = days.iterator();
-            while (iter.hasNext()) {
-                Widget w = iter.next();
+            for (Widget w : days) {
                 if (w instanceof Day) {
                     Day day = (Day) w;
                     if (day.getDate().equals(date)) {
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VFilterSelect.java b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VFilterSelect.java
index 3bc66e8390..0abee9b3b3 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VFilterSelect.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VFilterSelect.java
@@ -20,7 +20,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Date;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 
@@ -1092,10 +1091,8 @@ public class VFilterSelect extends Composite
             }
 
             clearItems();
-            final Iterator<FilterSelectSuggestion> it = suggestions.iterator();
             boolean isFirstIteration = true;
-            while (it.hasNext()) {
-                final FilterSelectSuggestion s = it.next();
+            for (final FilterSelectSuggestion s : suggestions) {
                 final MenuItem mi = new MenuItem(s.getDisplayString(), true, s);
                 String style = s.getStyle();
                 if (style != null) {
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VOptionGroup.java b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VOptionGroup.java
index 6150625547..4abcc75f4d 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VOptionGroup.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VOptionGroup.java
@@ -237,10 +237,8 @@ public class VOptionGroup extends VOptionGroupBase
 
     @Override
     public void setTabIndex(int tabIndex) {
-        for (Iterator<Widget> iterator = panel.iterator(); iterator
-                .hasNext();) {
-            FocusWidget widget = (FocusWidget) iterator.next();
-            widget.setTabIndex(tabIndex);
+        for (Widget widget : panel) {
+            ((FocusWidget) widget).setTabIndex(tabIndex);
         }
     }
 
@@ -269,9 +267,10 @@ public class VOptionGroup extends VOptionGroupBase
 
     @Override
     public void focus() {
-        Iterator<Widget> iterator = panel.iterator();
-        if (iterator.hasNext()) {
-            ((Focusable) iterator.next()).setFocus(true);
+        Iterator<Widget> it = panel.iterator();
+        if (it.hasNext()) {
+            ((Focusable) it.next()).setFocus(true);
+
         }
     }
 
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VScrollTable.java b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VScrollTable.java
index 364afb0592..9894264126 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VScrollTable.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VScrollTable.java
@@ -1315,13 +1315,12 @@ public class VScrollTable extends FlowPanel
             boolean updateFocus = rowsUnSelected || selectedRowKeys.size() == 0
                     || focusedRow == null;
             if (scrollBody != null) {
-                Iterator<Widget> iterator = scrollBody.iterator();
-                while (iterator.hasNext()) {
+                for (Widget w : scrollBody) {
                     /*
                      * Make the focus reflect to the server side state unless we
                      * are currently selecting multiple rows with keyboard.
                      */
-                    VScrollTableRow row = (VScrollTableRow) iterator.next();
+                    VScrollTableRow row = (VScrollTableRow) w;
                     boolean selected = selectedKeys.contains(row.getKey());
                     if (!selected && unSyncedselectionsBeforeRowFetch != null
                             && unSyncedselectionsBeforeRowFetch
@@ -2034,10 +2033,8 @@ public class VScrollTable extends FlowPanel
      */
     public VScrollTableRow getRenderedRowByKey(String key) {
         if (scrollBody != null) {
-            final Iterator<Widget> it = scrollBody.iterator();
-            VScrollTableRow r = null;
-            while (it.hasNext()) {
-                r = (VScrollTableRow) it.next();
+            for (Widget w : scrollBody) {
+                VScrollTableRow r = (VScrollTableRow) w;
                 if (r.getKey().equals(key)) {
                     return r;
                 }
@@ -2056,9 +2053,8 @@ public class VScrollTable extends FlowPanel
      */
     private VScrollTableRow getNextRow(VScrollTableRow row, int offset) {
         final Iterator<Widget> it = scrollBody.iterator();
-        VScrollTableRow r = null;
         while (it.hasNext()) {
-            r = (VScrollTableRow) it.next();
+            VScrollTableRow r = (VScrollTableRow) it.next();
             if (r == row) {
                 r = null;
                 while (offset >= 0 && it.hasNext()) {
@@ -2082,10 +2078,9 @@ public class VScrollTable extends FlowPanel
     private VScrollTableRow getPreviousRow(VScrollTableRow row, int offset) {
         final Iterator<Widget> it = scrollBody.iterator();
         final Iterator<Widget> offsetIt = scrollBody.iterator();
-        VScrollTableRow r = null;
         VScrollTableRow prev = null;
         while (it.hasNext()) {
-            r = (VScrollTableRow) it.next();
+            VScrollTableRow r = (VScrollTableRow) it.next();
             if (offset < 0) {
                 prev = (VScrollTableRow) offsetIt.next();
             }
@@ -3452,11 +3447,11 @@ public class VScrollTable extends FlowPanel
                 }
                 if (columnIndex < 0) {
                     columnIndex = 0;
-                    for (Iterator<Widget> it = tHead.iterator(); it
-                            .hasNext(); columnIndex++) {
-                        if (it.next() == this) {
+                    for (Widget w : tHead) {
+                        if (w == this) {
                             break;
                         }
+                        columnIndex++;
                     }
                 }
                 final int cw = scrollBody.getColWidth(columnIndex);
@@ -4079,11 +4074,10 @@ public class VScrollTable extends FlowPanel
          * Returns column alignments for visible columns
          */
         public char[] getColumnAlignments() {
-            final Iterator<Widget> it = visibleCells.iterator();
             final char[] aligns = new char[visibleCells.size()];
             int colIndex = 0;
-            while (it.hasNext()) {
-                aligns[colIndex++] = ((HeaderCell) it.next()).getAlign();
+            for (Widget w : visibleCells) {
+                aligns[colIndex++] = ((HeaderCell) w).getAlign();
             }
             return aligns;
         }
@@ -5439,9 +5433,8 @@ public class VScrollTable extends FlowPanel
         public void moveCol(int oldIndex, int newIndex) {
 
             // loop all rows and move given index to its new place
-            final Iterator<?> rows = iterator();
-            while (rows.hasNext()) {
-                final VScrollTableRow row = (VScrollTableRow) rows.next();
+            for (Widget w : this) {
+                final VScrollTableRow row = (VScrollTableRow) w;
 
                 final Element td = DOM.getChild(row.getElement(), oldIndex);
                 if (td != null) {
@@ -6921,7 +6914,6 @@ public class VScrollTable extends FlowPanel
                 return;
             }
 
-            Iterator<Widget> headCells = tHead.iterator();
             int usedMinimumWidth = 0;
             int totalExplicitColumnsWidths = 0;
             float expandRatioDivider = 0;
@@ -6931,8 +6923,8 @@ public class VScrollTable extends FlowPanel
             int hierarchyColumnIndex = getHierarchyColumnIndex();
             HeaderCell hierarchyHeaderInNeedOfFurtherHandling = null;
 
-            while (headCells.hasNext()) {
-                final HeaderCell hCell = (HeaderCell) headCells.next();
+            for (Widget widget : tHead) {
+                final HeaderCell hCell = (HeaderCell) widget;
                 boolean hasIndent = hierarchyColumnIndent > 0
                         && hCell.isHierarchyColumn();
                 if (hCell.isDefinedWidth()) {
@@ -7049,12 +7041,10 @@ public class VScrollTable extends FlowPanel
             }
 
             // we have some space that can be divided optimally
-            HeaderCell hCell;
             colIndex = 0;
-            headCells = tHead.iterator();
             int checksum = 0;
-            while (headCells.hasNext()) {
-                hCell = (HeaderCell) headCells.next();
+            for (Widget widget : tHead) {
+                HeaderCell hCell = (HeaderCell) widget;
                 if (hCell.isResizing) {
                     continue;
                 }
@@ -7107,10 +7097,9 @@ public class VScrollTable extends FlowPanel
                  * extra space is divided so if there is one then we give the
                  * first undefined column 1 more pixel
                  */
-                headCells = tHead.iterator();
                 colIndex = 0;
-                while (headCells.hasNext()) {
-                    HeaderCell hc = (HeaderCell) headCells.next();
+                for (Widget widget : tHead) {
+                    HeaderCell hc = (HeaderCell) widget;
                     if (!hc.isResizing && !hc.isDefinedWidth()) {
                         setColWidth(colIndex,
                                 hc.getWidthWithIndent() + availW - checksum,
@@ -7554,12 +7543,11 @@ public class VScrollTable extends FlowPanel
         private Class<? extends Widget> getRowClass() {
             // get the row type this way to make dd work in derived
             // implementations
-            Iterator<Widget> iterator = scrollBody.iterator();
-            if (iterator.hasNext()) {
-                return iterator.next().getClass();
-            } else {
-                return null;
+            Iterator<Widget> it = scrollBody.iterator();
+            if (it.hasNext()) {
+                return it.next().getClass();
             }
+            return null;
         }
 
         @Override
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VTree.java b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VTree.java
index acfbb02d70..2dce082305 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VTree.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VTree.java
@@ -19,7 +19,6 @@ package com.vaadin.v7.client.ui;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -1016,9 +1015,8 @@ public class VTree extends FocusElementPanel
             List<TreeNode> nodes = new LinkedList<TreeNode>();
 
             if (!isLeaf() && isChildrenLoaded()) {
-                Iterator<Widget> iter = childNodeContainer.iterator();
-                while (iter.hasNext()) {
-                    TreeNode node = (TreeNode) iter.next();
+                for (Widget w : childNodeContainer) {
+                    TreeNode node = (TreeNode) w;
                     nodes.add(node);
                 }
             }
@@ -1489,10 +1487,8 @@ public class VTree extends FocusElementPanel
             endNode = temp;
         }
 
-        Iterator<TreeNode> childIter = children.iterator();
         boolean startFound = false;
-        while (childIter.hasNext()) {
-            TreeNode node = childIter.next();
+        for (TreeNode node : children) {
             if (node == startNode) {
                 startFound = true;
             }
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VTreeTable.java b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VTreeTable.java
index dc76d6cd2d..99caa8bf44 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VTreeTable.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/VTreeTable.java
@@ -428,9 +428,8 @@ public class VTreeTable extends VScrollTable {
         @Override
         protected void calculateMaxIndent() {
             int maxIndent = 0;
-            Iterator<Widget> iterator = iterator();
-            while (iterator.hasNext()) {
-                VTreeTableRow next = (VTreeTableRow) iterator.next();
+            for (Widget w : this) {
+                VTreeTableRow next = (VTreeTableRow) w;
                 maxIndent = Math.max(maxIndent, next.getIndent());
             }
             this.maxIndent = maxIndent;
@@ -442,10 +441,8 @@ public class VTreeTable extends VScrollTable {
                 indentWidth = -1;
                 return;
             }
-            Iterator<Widget> iterator = iterator();
-            while (iterator.hasNext()) {
-                VTreeTableRow next = (VTreeTableRow) iterator.next();
-                next.setIndent();
+            for (Widget w : this) {
+                ((VTreeTableRow) w).setIndent();
             }
             calculateMaxIndent();
         }
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/calendar/schedule/DayToolbar.java b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/calendar/schedule/DayToolbar.java
index 4d7d1631c2..b7e152c010 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/calendar/schedule/DayToolbar.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/calendar/schedule/DayToolbar.java
@@ -15,8 +15,6 @@
  */
 package com.vaadin.v7.client.ui.calendar.schedule;
 
-import java.util.Iterator;
-
 import com.google.gwt.dom.client.Style.Unit;
 import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
@@ -158,9 +156,8 @@ public class DayToolbar extends HorizontalPanel implements ClickHandler {
     }
 
     private void updateDayLabelSizedStyleNames() {
-        Iterator<Widget> it = iterator();
-        while (it.hasNext()) {
-            updateWidgetSizedStyleName(it.next());
+        for (Widget w : this) {
+            updateWidgetSizedStyleName(w);
         }
     }
 
diff --git a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/table/TableConnector.java b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/table/TableConnector.java
index 091951bc8b..b4a00559b1 100644
--- a/compatibility-client/src/main/java/com/vaadin/v7/client/ui/table/TableConnector.java
+++ b/compatibility-client/src/main/java/com/vaadin/v7/client/ui/table/TableConnector.java
@@ -16,7 +16,6 @@
 package com.vaadin.v7.client.ui.table;
 
 import java.util.Collections;
-import java.util.Iterator;
 import java.util.List;
 
 import com.google.gwt.core.client.Scheduler;
@@ -190,7 +189,8 @@ public class TableConnector extends AbstractFieldConnector
 
         // Update child measure hint
         int childMeasureHint = uidl.hasAttribute("measurehint")
-                ? uidl.getIntAttribute("measurehint") : 0;
+                ? uidl.getIntAttribute("measurehint")
+                : 0;
         getWidget().setChildMeasurementHint(
                 ChildMeasurementHint.values()[childMeasureHint]);
 
@@ -451,9 +451,7 @@ public class TableConnector extends AbstractFieldConnector
      */
     public void showSavedContextMenu(ContextMenuDetails savedContextMenu) {
         if (isEnabled() && savedContextMenu != null) {
-            Iterator<Widget> iterator = getWidget().scrollBody.iterator();
-            while (iterator.hasNext()) {
-                Widget w = iterator.next();
+            for (Widget w : getWidget().scrollBody) {
                 VScrollTableRow row = (VScrollTableRow) w;
                 if (row.getKey().equals(savedContextMenu.rowKey)) {
                     row.showContextMenu(savedContextMenu.left,
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/data/util/AbstractBeanContainer.java b/compatibility-server/src/main/java/com/vaadin/v7/data/util/AbstractBeanContainer.java
index 2e93c2249f..7bb965846b 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/data/util/AbstractBeanContainer.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/data/util/AbstractBeanContainer.java
@@ -18,7 +18,6 @@ package com.vaadin.v7.data.util;
 import java.io.Serializable;
 import java.util.Collection;
 import java.util.HashMap;
-import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -846,9 +845,8 @@ public abstract class AbstractBeanContainer<IDTYPE, BEANTYPE>
         model.remove(propertyId);
 
         // If remove the Property from all Items
-        for (final Iterator<IDTYPE> i = getAllItemIds().iterator(); i
-                .hasNext();) {
-            getUnfilteredItem(i.next()).removeItemProperty(propertyId);
+        for (final IDTYPE id : getAllItemIds()) {
+            getUnfilteredItem(id).removeItemProperty(propertyId);
         }
 
         // Sends a change event
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/data/util/AbstractInMemoryContainer.java b/compatibility-server/src/main/java/com/vaadin/v7/data/util/AbstractInMemoryContainer.java
index 61d9d4f55f..3a1c179c34 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/data/util/AbstractInMemoryContainer.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/data/util/AbstractInMemoryContainer.java
@@ -525,9 +525,7 @@ public abstract class AbstractInMemoryContainer<ITEMIDTYPE, PROPERTYIDCLASS, ITE
         // Filter
         boolean equal = true;
         Iterator<ITEMIDTYPE> origIt = originalFilteredItemIds.iterator();
-        for (final Iterator<ITEMIDTYPE> i = getAllItemIds().iterator(); i
-                .hasNext();) {
-            final ITEMIDTYPE id = i.next();
+        for (final ITEMIDTYPE id : getAllItemIds()) {
             if (passesFilters(id)) {
                 // filtered list comes from the full list, can use ==
                 equal = equal && origIt.hasNext() && origIt.next() == id;
@@ -554,9 +552,7 @@ public abstract class AbstractInMemoryContainer<ITEMIDTYPE, PROPERTYIDCLASS, ITE
         if (getFilters().isEmpty()) {
             return true;
         }
-        final Iterator<Filter> i = getFilters().iterator();
-        while (i.hasNext()) {
-            final Filter f = i.next();
+        for (final Filter f : getFilters()) {
             if (!f.passesFilter(itemId, item)) {
                 return false;
             }
@@ -644,9 +640,7 @@ public abstract class AbstractInMemoryContainer<ITEMIDTYPE, PROPERTYIDCLASS, ITE
         if (getFilters().isEmpty() || propertyId == null) {
             return false;
         }
-        final Iterator<Filter> i = getFilters().iterator();
-        while (i.hasNext()) {
-            final Filter f = i.next();
+        for (final Filter f : getFilters()) {
             if (f.appliesToProperty(propertyId)) {
                 return true;
             }
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/data/util/ContainerHierarchicalWrapper.java b/compatibility-server/src/main/java/com/vaadin/v7/data/util/ContainerHierarchicalWrapper.java
index a4e9d74c53..e9f160dedd 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/data/util/ContainerHierarchicalWrapper.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/data/util/ContainerHierarchicalWrapper.java
@@ -23,7 +23,6 @@ import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashSet;
 import java.util.Hashtable;
-import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.Map;
@@ -167,8 +166,7 @@ public class ContainerHierarchicalWrapper implements Container.Hierarchical,
                 s.addAll(roots);
 
                 // Remove unnecessary items
-                for (final Iterator<Object> i = s.iterator(); i.hasNext();) {
-                    final Object id = i.next();
+                for (final Object id : s) {
                     if (!container.containsId(id)) {
                         removeFromHierarchyWrapper(id);
                     }
@@ -176,8 +174,7 @@ public class ContainerHierarchicalWrapper implements Container.Hierarchical,
 
                 // Add all the missing items
                 final Collection<?> ids = container.getItemIds();
-                for (final Iterator<?> i = ids.iterator(); i.hasNext();) {
-                    final Object id = i.next();
+                for (final Object id : ids) {
                     if (!s.contains(id)) {
                         addToHierarchyWrapper(id);
                         s.add(id);
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/data/util/ContainerOrderedWrapper.java b/compatibility-server/src/main/java/com/vaadin/v7/data/util/ContainerOrderedWrapper.java
index f7da00acd9..8979e7a5d6 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/data/util/ContainerOrderedWrapper.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/data/util/ContainerOrderedWrapper.java
@@ -19,7 +19,6 @@ package com.vaadin.v7.data.util;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Hashtable;
-import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -226,16 +225,14 @@ public class ContainerOrderedWrapper implements Container.Ordered,
 
             // Filter out all the missing items
             final LinkedList<?> l = new LinkedList<Object>(next.keySet());
-            for (final Iterator<?> i = l.iterator(); i.hasNext();) {
-                final Object id = i.next();
+            for (final Object id : l) {
                 if (!container.containsId(id)) {
                     removeFromOrderWrapper(id);
                 }
             }
 
             // Adds missing items
-            for (final Iterator<?> i = ids.iterator(); i.hasNext();) {
-                final Object id = i.next();
+            for (final Object id : ids) {
                 if (!next.containsKey(id) && last != id) {
                     addToOrderWrapper(id);
                 }
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/data/util/FilesystemContainer.java b/compatibility-server/src/main/java/com/vaadin/v7/data/util/FilesystemContainer.java
index 1799bdc72e..9fca1061fd 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/data/util/FilesystemContainer.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/data/util/FilesystemContainer.java
@@ -26,7 +26,6 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Date;
-import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 
@@ -428,8 +427,7 @@ public class FilesystemContainer implements Container.Hierarchical {
         final List<File> ll = Arrays.asList(l);
         Collections.sort(ll);
 
-        for (final Iterator<File> i = ll.iterator(); i.hasNext();) {
-            final File lf = i.next();
+        for (final File lf : ll) {
             col.add(lf);
             if (lf.isDirectory()) {
                 addItemIds(col, lf);
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/data/util/ListSet.java b/compatibility-server/src/main/java/com/vaadin/v7/data/util/ListSet.java
index 4c40c8c81a..291397cd63 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/data/util/ListSet.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/data/util/ListSet.java
@@ -20,7 +20,6 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.Map;
 
 /**
@@ -106,9 +105,7 @@ public class ListSet<E> extends ArrayList<E> {
     @Override
     public boolean addAll(Collection<? extends E> c) {
         boolean modified = false;
-        Iterator<? extends E> i = c.iterator();
-        while (i.hasNext()) {
-            E e = i.next();
+        for (E e : c) {
             if (contains(e)) {
                 continue;
             }
@@ -126,9 +123,7 @@ public class ListSet<E> extends ArrayList<E> {
         ensureCapacity(size() + c.size());
 
         boolean modified = false;
-        Iterator<? extends E> i = c.iterator();
-        while (i.hasNext()) {
-            E e = i.next();
+        for (E e : c) {
             if (contains(e)) {
                 continue;
             }
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/data/util/converter/StringToCollectionConverter.java b/compatibility-server/src/main/java/com/vaadin/v7/data/util/converter/StringToCollectionConverter.java
index ed65e621ec..da1122a3d9 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/data/util/converter/StringToCollectionConverter.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/data/util/converter/StringToCollectionConverter.java
@@ -15,14 +15,11 @@
  */
 package com.vaadin.v7.data.util.converter;
 
-import com.vaadin.data.Binder;
-
 import java.io.Serializable;
 import java.lang.reflect.Modifier;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.Locale;
 
 /**
@@ -41,7 +38,8 @@ import java.util.Locale;
  * @author Vaadin Ltd
  *
  * @deprecated As of 8.0, a lightweight lambda-based converter can be build with
- *  {@link Binder}{@code .forField(...).withConverter(...)} methods.
+ *             {@link com.vaadin.data.Binder
+ *             Binder}{@code .forField(...).withConverter(...)} methods.
  */
 @Deprecated
 public class StringToCollectionConverter
@@ -178,12 +176,12 @@ public class StringToCollectionConverter
         }
         StringBuilder builder = new StringBuilder();
         Converter converter = tokenConverter;
-        for (Iterator<?> iterator = value.iterator(); iterator.hasNext();) {
+        for (Object o : value) {
             if (converter == null) {
-                builder.append(iterator.next());
+                builder.append(o);
             } else {
-                builder.append(converter.convertToPresentation(iterator.next(),
-                        targetType, locale));
+                builder.append(
+                        converter.convertToPresentation(o, targetType, locale));
             }
             builder.append(delimiter);
         }
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/ui/AbstractField.java b/compatibility-server/src/main/java/com/vaadin/v7/ui/AbstractField.java
index 653ad3f6bf..066dd78c11 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/ui/AbstractField.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/ui/AbstractField.java
@@ -21,11 +21,9 @@ import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Locale;
-import java.util.logging.Logger;
 
 import org.jsoup.nodes.Attributes;
 import org.jsoup.nodes.Element;
@@ -652,9 +650,8 @@ public abstract class AbstractField<T> extends AbstractLegacyComponent
             final Collection<Validator> validators = ((Validatable) dataSource)
                     .getValidators();
             if (validators != null) {
-                for (final Iterator<Validator> i = validators.iterator(); i
-                        .hasNext();) {
-                    addValidator(i.next());
+                for (final Validator v : validators) {
+                    addValidator(v);
                 }
             }
         }
@@ -1766,8 +1763,7 @@ public abstract class AbstractField<T> extends AbstractLegacyComponent
     @Override
     public void writeDesign(Element design, DesignContext designContext) {
         super.writeDesign(design, designContext);
-        AbstractField<?> def = designContext
-                .getDefaultInstance(this);
+        AbstractField<?> def = designContext.getDefaultInstance(this);
         Attributes attr = design.attributes();
         // handle readonly
         DesignAttributeHandler.writeAttribute("readonly", attr,
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/ui/AbstractSelect.java b/compatibility-server/src/main/java/com/vaadin/v7/ui/AbstractSelect.java
index 894936e1cd..a6472c61db 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/ui/AbstractSelect.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/ui/AbstractSelect.java
@@ -22,7 +22,6 @@ import java.util.Collections;
 import java.util.EventObject;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.LinkedList;
 import java.util.List;
@@ -404,11 +403,9 @@ public abstract class AbstractSelect extends AbstractField<Object> implements
             target.endTag("so");
         }
 
-        final Iterator<?> i = getItemIds().iterator();
         // Paints the available selection options from data source
-        while (i.hasNext()) {
+        for (final Object id : getItemIds()) {
             // Gets the option attribute values
-            final Object id = i.next();
             if (!isNullSelectionAllowed() && id != null
                     && id.equals(getNullSelectionItemId())) {
                 // Remove item if it's the null selection item but null
@@ -1941,8 +1938,8 @@ public abstract class AbstractSelect extends AbstractField<Object> implements
                 }
                 Collection<?> pids = i.getItemPropertyIds();
                 if (pids != null) {
-                    for (Iterator<?> it = pids.iterator(); it.hasNext();) {
-                        Property<?> p = i.getItemProperty(it.next());
+                    for (Object id : pids) {
+                        Property<?> p = i.getItemProperty(id);
                         if (p != null
                                 && p instanceof Property.ValueChangeNotifier) {
                             ((Property.ValueChangeNotifier) p)
@@ -1977,9 +1974,7 @@ public abstract class AbstractSelect extends AbstractField<Object> implements
         }
 
         public void clear() {
-            for (Iterator<Object> it = captionChangeNotifiers.iterator(); it
-                    .hasNext();) {
-                Object notifier = it.next();
+            for (Object notifier : captionChangeNotifiers) {
                 if (notifier instanceof Item.PropertySetChangeNotifier) {
                     ((Item.PropertySetChangeNotifier) notifier)
                             .removePropertySetChangeListener(
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/ui/ComboBox.java b/compatibility-server/src/main/java/com/vaadin/v7/ui/ComboBox.java
index b9960bba4f..d180aa34b9 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/ui/ComboBox.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/ui/ComboBox.java
@@ -19,7 +19,6 @@ package com.vaadin.v7.ui;
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -286,12 +285,9 @@ public class ComboBox extends AbstractSelect
                 target.endTag("so");
             }
 
-            final Iterator<?> i = options.iterator();
             // Paints the available selection options from data source
 
-            while (i.hasNext()) {
-
-                final Object id = i.next();
+            for (final Object id : options) {
 
                 if (!isNullSelectionAllowed() && id != null
                         && id.equals(getNullSelectionItemId())
@@ -690,8 +686,7 @@ public class ComboBox extends AbstractSelect
         prevfilterstring = filterstring;
 
         filteredOptions = new LinkedList<Object>();
-        for (final Iterator<?> it = items.iterator(); it.hasNext();) {
-            final Object itemId = it.next();
+        for (final Object itemId : items) {
             String caption = getItemCaption(itemId);
             if (caption == null || caption.equals("")) {
                 continue;
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/ui/Form.java b/compatibility-server/src/main/java/com/vaadin/v7/ui/Form.java
index 63a6118c58..b37bcd933b 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/ui/Form.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/ui/Form.java
@@ -245,9 +245,8 @@ public class Form extends AbstractField<Object>
         // getErrorMessage() recursively instead of validate().
         ErrorMessage validationError = null;
         if (isValidationVisible()) {
-            for (final Iterator<Object> i = propertyIds.iterator(); i
-                    .hasNext();) {
-                Object f = fields.get(i.next());
+            for (final Object id : propertyIds) {
+                Object f = fields.get(id);
                 if (f instanceof AbstractComponent) {
                     AbstractComponent field = (AbstractComponent) f;
 
@@ -337,9 +336,9 @@ public class Form extends AbstractField<Object>
         }
 
         // Try to commit all
-        for (final Iterator<Object> i = propertyIds.iterator(); i.hasNext();) {
+        for (final Object id : propertyIds) {
             try {
-                final Field<?> f = fields.get(i.next());
+                final Field<?> f = fields.get(id);
                 // Commit only non-readonly fields.
                 if (!f.isReadOnly()) {
                     f.commit();
@@ -362,12 +361,9 @@ public class Form extends AbstractField<Object>
         }
 
         // Commit problems
-        final Throwable[] causes = new Throwable[problems.size()];
-        int index = 0;
-        for (final Iterator<SourceException> i = problems.iterator(); i
-                .hasNext();) {
-            causes[index++] = i.next();
-        }
+        final Throwable[] causes = problems
+                .toArray(new Throwable[problems.size()]);
+
         final Buffered.SourceException e = new Buffered.SourceException(this,
                 causes);
         currentBufferedSourceException = e;
@@ -385,9 +381,9 @@ public class Form extends AbstractField<Object>
         LinkedList<SourceException> problems = null;
 
         // Try to discard all changes
-        for (final Iterator<Object> i = propertyIds.iterator(); i.hasNext();) {
+        for (final Object id : propertyIds) {
             try {
-                fields.get(i.next()).discard();
+                fields.get(id).discard();
             } catch (final Buffered.SourceException e) {
                 if (problems == null) {
                     problems = new LinkedList<SourceException>();
@@ -406,12 +402,9 @@ public class Form extends AbstractField<Object>
         }
 
         // Discards problems occurred
-        final Throwable[] causes = new Throwable[problems.size()];
-        int index = 0;
-        for (final Iterator<SourceException> i = problems.iterator(); i
-                .hasNext();) {
-            causes[index++] = i.next();
-        }
+        final Throwable[] causes = problems
+                .toArray(new Throwable[problems.size()]);
+
         final Buffered.SourceException e = new Buffered.SourceException(this,
                 causes);
         currentBufferedSourceException = e;
@@ -425,8 +418,8 @@ public class Form extends AbstractField<Object>
      */
     @Override
     public boolean isModified() {
-        for (final Iterator<Object> i = propertyIds.iterator(); i.hasNext();) {
-            final Field<?> f = fields.get(i.next());
+        for (final Object id : propertyIds) {
+            final Field<?> f = fields.get(id);
             if (f != null && f.isModified()) {
                 return true;
             }
@@ -443,9 +436,8 @@ public class Form extends AbstractField<Object>
     public void setBuffered(boolean buffered) {
         if (buffered != this.buffered) {
             this.buffered = buffered;
-            for (final Iterator<Object> i = propertyIds.iterator(); i
-                    .hasNext();) {
-                fields.get(i.next()).setBuffered(buffered);
+            for (final Object id : propertyIds) {
+                fields.get(id).setBuffered(buffered);
             }
         }
     }
@@ -741,8 +733,7 @@ public class Form extends AbstractField<Object>
         }
 
         // Adds all the properties to this form
-        for (final Iterator<?> i = propertyIds.iterator(); i.hasNext();) {
-            final Object id = i.next();
+        for (final Object id : propertyIds) {
             final Property<?> property = itemDatasource.getItemProperty(id);
             if (id != null && property != null) {
                 final Field<?> f = fieldFactory.createField(itemDatasource, id,
@@ -890,9 +881,7 @@ public class Form extends AbstractField<Object>
         }
         if (value != null && !found) {
             if (value instanceof Collection) {
-                for (final Iterator<?> it = ((Collection<?>) value)
-                        .iterator(); it.hasNext();) {
-                    final Object val = it.next();
+                for (final Object val : ((Collection<?>) value)) {
                     found = false;
                     for (int i = 0; i < values.length && !found; i++) {
                         if (values[i] == val
@@ -965,8 +954,8 @@ public class Form extends AbstractField<Object>
     @Override
     public void validate() throws InvalidValueException {
         super.validate();
-        for (final Iterator<Object> i = propertyIds.iterator(); i.hasNext();) {
-            fields.get(i.next()).validate();
+        for (final Object id : propertyIds) {
+            fields.get(id).validate();
         }
     }
 
@@ -999,8 +988,8 @@ public class Form extends AbstractField<Object>
     @Override
     public void setReadOnly(boolean readOnly) {
         super.setReadOnly(readOnly);
-        for (final Iterator<?> i = propertyIds.iterator(); i.hasNext();) {
-            fields.get(i.next()).setReadOnly(readOnly);
+        for (final Object id : propertyIds) {
+            fields.get(id).setReadOnly(readOnly);
         }
     }
 
@@ -1179,9 +1168,8 @@ public class Form extends AbstractField<Object>
     @Override
     public void setTabIndex(int tabIndex) {
         super.setTabIndex(tabIndex);
-        for (final Iterator<?> i = getItemPropertyIds().iterator(); i
-                .hasNext();) {
-            getField(i.next()).setTabIndex(tabIndex);
+        for (final Object id : getItemPropertyIds()) {
+            getField(id).setTabIndex(tabIndex);
         }
     }
 
@@ -1192,8 +1180,7 @@ public class Form extends AbstractField<Object>
     @Override
     public void setImmediate(boolean immediate) {
         super.setImmediate(immediate);
-        for (Iterator<Field<?>> i = fields.values().iterator(); i.hasNext();) {
-            Field<?> f = i.next();
+        for (Field<?> f : fields.values()) {
             if (f instanceof AbstractLegacyComponent) {
                 ((AbstractLegacyComponent) f).setImmediate(immediate);
             }
@@ -1208,9 +1195,7 @@ public class Form extends AbstractField<Object>
      */
     @Override
     public boolean isEmpty() {
-
-        for (Iterator<Field<?>> i = fields.values().iterator(); i.hasNext();) {
-            Field<?> f = i.next();
+        for (Field<?> f : fields.values()) {
             if (f instanceof AbstractField) {
                 if (!((AbstractField<?>) f).isEmpty()) {
                     return false;
@@ -1223,8 +1208,7 @@ public class Form extends AbstractField<Object>
 
     @Override
     public void clear() {
-        for (Iterator<Field<?>> i = fields.values().iterator(); i.hasNext();) {
-            Field<?> f = i.next();
+        for (Field<?> f : fields.values()) {
             if (f instanceof AbstractField) {
                 ((AbstractField<?>) f).clear();
             }
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/ui/Grid.java b/compatibility-server/src/main/java/com/vaadin/v7/ui/Grid.java
index 387c4eebf4..4349ad49b4 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/ui/Grid.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/ui/Grid.java
@@ -1792,10 +1792,11 @@ public class Grid extends AbstractComponent
                         selection);
                 if (selection.size() + itemIds.size() >= selectionLimit) {
                     // Add one at a time if there's a risk of overflow
-                    Iterator<?> iterator = itemIds.iterator();
-                    while (iterator.hasNext()
-                            && selection.size() < selectionLimit) {
-                        selection.add(iterator.next());
+                    for (Object id : itemIds) {
+                        if (selection.size() >= selectionLimit) {
+                            break;
+                        }
+                        selection.add(id);
                     }
                 } else {
                     selection.addAll(itemIds);
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/ui/Table.java b/compatibility-server/src/main/java/com/vaadin/v7/ui/Table.java
index c99757ee04..9002f11c77 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/ui/Table.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/ui/Table.java
@@ -738,9 +738,8 @@ public class Table extends AbstractSelect implements Action.Container,
         }
         final String[] headers = new String[visibleColumns.size()];
         int i = 0;
-        for (final Iterator<Object> it = visibleColumns.iterator(); it
-                .hasNext(); i++) {
-            headers[i] = getColumnHeader(it.next());
+        for (final Object column : visibleColumns) {
+            headers[i++] = getColumnHeader(column);
         }
         return headers;
     }
@@ -770,9 +769,11 @@ public class Table extends AbstractSelect implements Action.Container,
 
         this.columnHeaders.clear();
         int i = 0;
-        for (final Iterator<Object> it = visibleColumns.iterator(); it.hasNext()
-                && i < columnHeaders.length; i++) {
-            this.columnHeaders.put(it.next(), columnHeaders[i]);
+        for (final Object column : visibleColumns) {
+            if (i >= columnHeaders.length) {
+                break;
+            }
+            this.columnHeaders.put(column, columnHeaders[i++]);
         }
 
         markAsDirty();
@@ -797,9 +798,8 @@ public class Table extends AbstractSelect implements Action.Container,
         }
         final Resource[] icons = new Resource[visibleColumns.size()];
         int i = 0;
-        for (final Iterator<Object> it = visibleColumns.iterator(); it
-                .hasNext(); i++) {
-            icons[i] = columnIcons.get(it.next());
+        for (final Object column : visibleColumns) {
+            icons[i++] = columnIcons.get(column);
         }
 
         return icons;
@@ -829,9 +829,11 @@ public class Table extends AbstractSelect implements Action.Container,
 
         this.columnIcons.clear();
         int i = 0;
-        for (final Iterator<Object> it = visibleColumns.iterator(); it.hasNext()
-                && i < columnIcons.length; i++) {
-            this.columnIcons.put(it.next(), columnIcons[i]);
+        for (final Object column : visibleColumns) {
+            if (i >= columnIcons.length) {
+                break;
+            }
+            this.columnIcons.put(column, columnIcons[i++]);
         }
 
         markAsDirty();
@@ -861,9 +863,8 @@ public class Table extends AbstractSelect implements Action.Container,
         }
         final Align[] alignments = new Align[visibleColumns.size()];
         int i = 0;
-        for (final Iterator<Object> it = visibleColumns.iterator(); it
-                .hasNext(); i++) {
-            alignments[i] = getColumnAlignment(it.next());
+        for (final Object column : visibleColumns) {
+            alignments[i++] = getColumnAlignment(column);
         }
 
         return alignments;
@@ -897,9 +898,11 @@ public class Table extends AbstractSelect implements Action.Container,
         // Resets the alignments
         final Map<Object, Align> newCA = new HashMap<Object, Align>();
         int i = 0;
-        for (final Iterator<Object> it = visibleColumns.iterator(); it.hasNext()
-                && i < columnAlignments.length; i++) {
-            newCA.put(it.next(), columnAlignments[i]);
+        for (final Object column : visibleColumns) {
+            if (i >= columnAlignments.length) {
+                break;
+            }
+            newCA.put(column, columnAlignments[i++]);
         }
         this.columnAlignments = newCA;
 
@@ -1480,9 +1483,7 @@ public class Table extends AbstractSelect implements Action.Container,
                 newOrder.add(columnOrder[i]);
             }
         }
-        for (final Iterator<Object> it = visibleColumns.iterator(); it
-                .hasNext();) {
-            final Object columnId = it.next();
+        for (final Object columnId : visibleColumns) {
             if (!newOrder.contains(columnId)) {
                 newOrder.add(columnId);
             }
@@ -2476,9 +2477,7 @@ public class Table extends AbstractSelect implements Action.Container,
             HashSet<Property<?>> oldListenedProperties,
             HashSet<Component> oldVisibleComponents) {
         if (oldVisibleComponents != null) {
-            for (final Iterator<Component> i = oldVisibleComponents
-                    .iterator(); i.hasNext();) {
-                Component c = i.next();
+            for (final Component c : oldVisibleComponents) {
                 if (!visibleComponents.contains(c)) {
                     unregisterComponent(c);
                 }
@@ -2486,9 +2485,8 @@ public class Table extends AbstractSelect implements Action.Container,
         }
 
         if (oldListenedProperties != null) {
-            for (final Iterator<Property<?>> i = oldListenedProperties
-                    .iterator(); i.hasNext();) {
-                Property.ValueChangeNotifier o = (ValueChangeNotifier) i.next();
+            for (final Property<?> p : oldListenedProperties) {
+                Property.ValueChangeNotifier o = (ValueChangeNotifier) p;
                 if (!listenedProperties.contains(o)) {
                     o.removeListener(this);
                 }
@@ -2601,8 +2599,7 @@ public class Table extends AbstractSelect implements Action.Container,
 
         // remove generated columns from the list of columns being assigned
         final LinkedList<Object> availableCols = new LinkedList<Object>();
-        for (Iterator<Object> it = visibleColumns.iterator(); it.hasNext();) {
-            Object id = it.next();
+        for (Object id : visibleColumns) {
             if (!columnGenerators.containsKey(id)) {
                 availableCols.add(id);
             }
@@ -2776,8 +2773,7 @@ public class Table extends AbstractSelect implements Action.Container,
 
         // don't add the same id twice
         Collection<Object> col = new LinkedList<Object>();
-        for (Iterator<?> it = visibleIds.iterator(); it.hasNext();) {
-            Object id = it.next();
+        for (Object id : visibleIds) {
             if (!col.contains(id)) {
                 col.add(id);
             }
@@ -3040,9 +3036,7 @@ public class Table extends AbstractSelect implements Action.Container,
                     for (Object id : ids) {
                         idSet.add(columnIdMap.get(id.toString()));
                     }
-                    for (final Iterator<Object> it = visibleColumns
-                            .iterator(); it.hasNext();) {
-                        Object propertyId = it.next();
+                    for (final Object propertyId : visibleColumns) {
                         if (isColumnCollapsed(propertyId)) {
                             if (!idSet.contains(propertyId)) {
                                 setColumnCollapsed(propertyId, false);
@@ -3803,8 +3797,7 @@ public class Table extends AbstractSelect implements Action.Container,
         if (isMultiSelect()) {
             HashSet<?> sel = new HashSet<Object>((Set<?>) getValue());
             Collection<?> vids = getVisibleItemIds();
-            for (Iterator<?> it = vids.iterator(); it.hasNext();) {
-                Object id = it.next();
+            for (Object id : vids) {
                 if (sel.contains(id)) {
                     selectedKeys.add(itemIdMapper.key(id));
                 }
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/ui/Tree.java b/compatibility-server/src/main/java/com/vaadin/v7/ui/Tree.java
index 6b3a4497c8..6a2da71bb7 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/ui/Tree.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/ui/Tree.java
@@ -780,10 +780,8 @@ public class Tree extends AbstractSelect implements Container.Hierarchical,
                 // Actions
                 if (actionHandlers != null) {
                     final List<String> keys = new ArrayList<String>();
-                    final Iterator<Action.Handler> ahi = actionHandlers
-                            .iterator();
-                    while (ahi.hasNext()) {
-                        final Action[] aa = ahi.next().getActions(itemId, this);
+                    for (Action.Handler ah : actionHandlers) {
+                        final Action[] aa = ah.getActions(itemId, this);
                         if (aa != null) {
                             for (int ai = 0; ai < aa.length; ai++) {
                                 final String akey = actionMapper.key(aa[ai]);
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/ui/Upload.java b/compatibility-server/src/main/java/com/vaadin/v7/ui/Upload.java
index 6ded53b3a1..a9a09ae49b 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/ui/Upload.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/ui/Upload.java
@@ -20,7 +20,6 @@ import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Collection;
 import java.util.Collections;
-import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.Map;
 
@@ -926,9 +925,7 @@ public class Upload extends AbstractLegacyComponent
         // this is implemented differently than other listeners to maintain
         // backwards compatibility
         if (progressListeners != null) {
-            for (Iterator<ProgressListener> it = progressListeners
-                    .iterator(); it.hasNext();) {
-                ProgressListener l = it.next();
+            for (ProgressListener l : progressListeners) {
                 l.updateProgress(totalBytes, contentLength);
             }
         }
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/ui/components/colorpicker/ColorPickerHistory.java b/compatibility-server/src/main/java/com/vaadin/v7/ui/components/colorpicker/ColorPickerHistory.java
index 09a7de6aff..0cab53c13e 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/ui/components/colorpicker/ColorPickerHistory.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/ui/components/colorpicker/ColorPickerHistory.java
@@ -118,14 +118,7 @@ public class ColorPickerHistory extends CustomComponent
         ArrayBlockingQueue<Color> colorHistory = getColorHistory();
 
         // Check that the color does not already exist
-        boolean exists = false;
-        Iterator<Color> iter = colorHistory.iterator();
-        while (iter.hasNext()) {
-            if (color.equals(iter.next())) {
-                exists = true;
-                break;
-            }
-        }
+        boolean exists = colorHistory.contains(color);
 
         // If the color does not exist then add it
         if (!exists) {
@@ -145,7 +138,7 @@ public class ColorPickerHistory extends CustomComponent
 
         // Create 2d color map
         Color[][] colors = new Color[rows][columns];
-        iter = colorList.iterator();
+        Iterator<Color> iter = colorList.iterator();
 
         for (int row = 0; row < rows; row++) {
             for (int col = 0; col < columns; col++) {
diff --git a/compatibility-server/src/main/java/com/vaadin/v7/ui/components/colorpicker/ColorPickerPopup.java b/compatibility-server/src/main/java/com/vaadin/v7/ui/components/colorpicker/ColorPickerPopup.java
index 306c4e78aa..71d8ef7a2c 100644
--- a/compatibility-server/src/main/java/com/vaadin/v7/ui/components/colorpicker/ColorPickerPopup.java
+++ b/compatibility-server/src/main/java/com/vaadin/v7/ui/components/colorpicker/ColorPickerPopup.java
@@ -19,7 +19,6 @@ import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 import java.util.logging.Level;
@@ -479,7 +478,7 @@ public class ColorPickerPopup extends Window
             }
 
             resize.setData(new Boolean(!state));
-        }  else if (event.getButton() == ok) {
+        } else if (event.getButton() == ok) {
             // Ok button was clicked
             history.setColor(getColor());
             fireColorChanged();
@@ -599,9 +598,8 @@ public class ColorPickerPopup extends Window
      * @return true if tab is visible, false otherwise
      */
     private boolean tabIsVisible(Component tab) {
-        Iterator<Component> tabIterator = tabs.getComponentIterator();
-        while (tabIterator.hasNext()) {
-            if (tabIterator.next() == tab) {
+        for (Component comp : tabs) {
+            if (comp == tab) {
                 return true;
             }
         }
@@ -614,10 +612,8 @@ public class ColorPickerPopup extends Window
      * @return The number of tabs visible
      */
     private int tabsNumVisible() {
-        Iterator<Component> tabIterator = tabs.getComponentIterator();
         int tabCounter = 0;
-        while (tabIterator.hasNext()) {
-            tabIterator.next();
+        for (Component comp : tabs) {
             tabCounter++;
         }
         return tabCounter;
diff --git a/compatibility-server/src/test/java/com/vaadin/v7/data/util/BeanItemContainerTest.java b/compatibility-server/src/test/java/com/vaadin/v7/data/util/BeanItemContainerTest.java
index 31d96fb47e..dee7c3fee3 100644
--- a/compatibility-server/src/test/java/com/vaadin/v7/data/util/BeanItemContainerTest.java
+++ b/compatibility-server/src/test/java/com/vaadin/v7/data/util/BeanItemContainerTest.java
@@ -9,7 +9,6 @@ import static org.junit.Assert.assertTrue;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -60,9 +59,8 @@ public class BeanItemContainerTest extends AbstractBeanContainerTestBase {
 
         beanItemContainer.removeAllItems();
 
-        Iterator<ClassName> it = nameToBean.values().iterator();
-        while (it.hasNext()) {
-            beanItemContainer.addBean(it.next());
+        for (ClassName name : nameToBean.values()) {
+            beanItemContainer.addBean(name);
         }
     }
 
diff --git a/compatibility-server/src/test/java/com/vaadin/v7/data/util/ContainerSortingTest.java b/compatibility-server/src/test/java/com/vaadin/v7/data/util/ContainerSortingTest.java
index 860f3b7b15..539835f1c5 100644
--- a/compatibility-server/src/test/java/com/vaadin/v7/data/util/ContainerSortingTest.java
+++ b/compatibility-server/src/test/java/com/vaadin/v7/data/util/ContainerSortingTest.java
@@ -1,7 +1,6 @@
 package com.vaadin.v7.data.util;
 
 import java.util.HashMap;
-import java.util.Iterator;
 import java.util.Map;
 
 import org.junit.Test;
@@ -154,10 +153,8 @@ public class ContainerSortingTest {
     private void verifyOrder(Container.Sortable ic, Object[] idOrder) {
         int size = ic.size();
         Object[] actual = new Object[size];
-        Iterator<?> i = ic.getItemIds().iterator();
         int index = 0;
-        while (i.hasNext()) {
-            Object o = i.next();
+        for (Object o : ic.getItemIds()) {
             if (o.getClass() == Integer.class
                     && idOrder[index].getClass() == String.class) {
                 o = idToName.get(o);
diff --git a/server/src/main/java/com/vaadin/server/widgetsetutils/ClassPathExplorer.java b/server/src/main/java/com/vaadin/server/widgetsetutils/ClassPathExplorer.java
index 65e3413122..66ba4d0d9f 100644
--- a/server/src/main/java/com/vaadin/server/widgetsetutils/ClassPathExplorer.java
+++ b/server/src/main/java/com/vaadin/server/widgetsetutils/ClassPathExplorer.java
@@ -24,7 +24,6 @@ import java.net.URL;
 import java.net.URLConnection;
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -533,9 +532,7 @@ public class ClassPathExplorer {
         }
 
         URL firstDirectory = null;
-        Iterator<String> it = rawClasspathEntries.iterator();
-        while (it.hasNext()) {
-            String entry = it.next();
+        for (String entry : rawClasspathEntries) {
 
             File directory = new File(entry);
             if (directory.exists() && !directory.isHidden()
diff --git a/server/src/main/java/com/vaadin/server/widgetsetutils/WidgetSetBuilder.java b/server/src/main/java/com/vaadin/server/widgetsetutils/WidgetSetBuilder.java
index fc01891b2e..608f84782c 100644
--- a/server/src/main/java/com/vaadin/server/widgetsetutils/WidgetSetBuilder.java
+++ b/server/src/main/java/com/vaadin/server/widgetsetutils/WidgetSetBuilder.java
@@ -29,7 +29,6 @@ import java.net.URISyntaxException;
 import java.net.URL;
 import java.util.Collection;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -116,9 +115,7 @@ public class WidgetSetBuilder {
                     content);
 
             // add widgetsets that do not exist
-            Iterator<String> i = availableWidgetSets.keySet().iterator();
-            while (i.hasNext()) {
-                String ws = i.next();
+            for (String ws : availableWidgetSets.keySet()) {
                 if (ws.equals(widgetset)) {
                     // do not inherit the module itself
                     continue;
diff --git a/server/src/main/java/com/vaadin/ui/ConnectorTracker.java b/server/src/main/java/com/vaadin/ui/ConnectorTracker.java
index a128e24e95..2ac5e33f34 100644
--- a/server/src/main/java/com/vaadin/ui/ConnectorTracker.java
+++ b/server/src/main/java/com/vaadin/ui/ConnectorTracker.java
@@ -399,10 +399,9 @@ public class ConnectorTracker implements Serializable {
     }
 
     private static boolean hasVisibleChild(ClientConnector parent) {
-        Iterator<? extends ClientConnector> iterator = AbstractClientConnector
-                .getAllChildrenIterable(parent).iterator();
-        while (iterator.hasNext()) {
-            ClientConnector child = iterator.next();
+        Iterable<? extends ClientConnector> iterable = AbstractClientConnector
+                .getAllChildrenIterable(parent);
+        for (ClientConnector child : iterable) {
             if (LegacyCommunicationManager.isConnectorVisibleToClient(child)) {
                 return true;
             }
diff --git a/server/src/main/java/com/vaadin/ui/GridLayout.java b/server/src/main/java/com/vaadin/ui/GridLayout.java
index b4d97018ce..b7bbcd061b 100644
--- a/server/src/main/java/com/vaadin/ui/GridLayout.java
+++ b/server/src/main/java/com/vaadin/ui/GridLayout.java
@@ -217,16 +217,16 @@ public class GridLayout extends AbstractLayout
         // Inserts the component to right place at the list
         // Respect top-down, left-right ordering
         // component.setParent(this);
-        final Iterator<Component> i = components.iterator();
         final Map<Connector, ChildComponentData> childDataMap = getState().childData;
         int index = 0;
         boolean done = false;
-        while (!done && i.hasNext()) {
-            final ChildComponentData existingArea = childDataMap.get(i.next());
+        for (Component c : components) {
+            final ChildComponentData existingArea = childDataMap.get(c);
             if ((existingArea.row1 >= row1 && existingArea.column1 > column1)
                     || existingArea.row1 > row1) {
                 components.add(index, component);
                 done = true;
+                break;
             }
             index++;
         }
diff --git a/server/src/main/java/com/vaadin/ui/MenuBar.java b/server/src/main/java/com/vaadin/ui/MenuBar.java
index 35988bb84d..f7682408d4 100644
--- a/server/src/main/java/com/vaadin/ui/MenuBar.java
+++ b/server/src/main/java/com/vaadin/ui/MenuBar.java
@@ -20,7 +20,6 @@ import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Deque;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
@@ -169,9 +168,8 @@ public class MenuBar extends AbstractComponent
         if (variables.containsKey("clickedId")) {
 
             Integer clickedId = (Integer) variables.get("clickedId");
-            Iterator<MenuItem> itr = getItems().iterator();
-            while (itr.hasNext()) {
-                items.push(itr.next());
+            for (MenuItem i : getItems()) {
+                items.push(i);
             }
 
             MenuItem tmpItem = null;
@@ -182,9 +180,8 @@ public class MenuBar extends AbstractComponent
                 found = (clickedId == tmpItem.getId());
 
                 if (tmpItem.hasChildren()) {
-                    itr = tmpItem.getChildren().iterator();
-                    while (itr.hasNext()) {
-                        items.push(itr.next());
+                    for (MenuItem i : tmpItem.getChildren()) {
+                        items.push(i);
                     }
                 }
 
diff --git a/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerHistory.java b/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerHistory.java
index 41606737d5..33ca7267ec 100644
--- a/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerHistory.java
+++ b/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerHistory.java
@@ -109,14 +109,7 @@ public class ColorPickerHistory extends CustomField<Color> {
         ArrayBlockingQueue<Color> colorHistory = getColorHistory();
 
         // Check that the color does not already exist
-        boolean exists = false;
-        Iterator<Color> iter = colorHistory.iterator();
-        while (iter.hasNext()) {
-            if (color.equals(iter.next())) {
-                exists = true;
-                break;
-            }
-        }
+        boolean exists = colorHistory.contains(color);
 
         // If the color does not exist then add it
         if (!exists) {
@@ -136,7 +129,7 @@ public class ColorPickerHistory extends CustomField<Color> {
 
         // Create 2d color map
         Color[][] colors = new Color[ROWS][COLUMNS];
-        iter = colorList.iterator();
+        Iterator<Color> iter = colorList.iterator();
 
         for (int row = 0; row < ROWS; row++) {
             for (int col = 0; col < COLUMNS; col++) {
diff --git a/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerPopup.java b/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerPopup.java
index 8d945e9e9c..435f20d64f 100644
--- a/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerPopup.java
+++ b/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerPopup.java
@@ -18,7 +18,6 @@ package com.vaadin.ui.components.colorpicker;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Objects;
 import java.util.Set;
@@ -761,10 +760,8 @@ public class ColorPickerPopup extends Window implements HasValue<Color> {
                     .setRequiredIndicatorVisible(isRequiredIndicatorVisible());
         }
         if (component instanceof HasComponents) {
-            Iterator<Component> iterator = ((HasComponents) component)
-                    .iterator();
-            while (iterator.hasNext()) {
-                updateColorComponents(iterator.next());
+            for (Component c : (HasComponents) component) {
+                updateColorComponents(c);
             }
         }
     }
diff --git a/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerPreview.java b/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerPreview.java
index 6953d980f4..485fdcc721 100644
--- a/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerPreview.java
+++ b/server/src/main/java/com/vaadin/ui/components/colorpicker/ColorPickerPreview.java
@@ -15,7 +15,6 @@
  */
 package com.vaadin.ui.components.colorpicker;
 
-import java.util.Iterator;
 import java.util.Objects;
 
 import com.vaadin.data.HasValue;
@@ -220,10 +219,8 @@ public class ColorPickerPreview extends CssLayout implements HasValue<Color> {
             ((HasValue<?>) component).setReadOnly(isReadOnly());
         }
         if (component instanceof HasComponents) {
-            Iterator<Component> iterator = ((HasComponents) component)
-                    .iterator();
-            while (iterator.hasNext()) {
-                updateColorComponents(iterator.next());
+            for (Component c : (HasComponents) component) {
+                updateColorComponents(c);
             }
         }
     }
diff --git a/server/src/test/java/com/vaadin/tests/server/ClassesSerializableTest.java b/server/src/test/java/com/vaadin/tests/server/ClassesSerializableTest.java
index c42a11e31d..aa37e860d7 100644
--- a/server/src/test/java/com/vaadin/tests/server/ClassesSerializableTest.java
+++ b/server/src/test/java/com/vaadin/tests/server/ClassesSerializableTest.java
@@ -19,7 +19,6 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Enumeration;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Optional;
 import java.util.jar.JarEntry;
@@ -119,7 +118,7 @@ public class ClassesSerializableTest {
             classes.addAll(findServerClasses(location));
         }
 
-        List<Field> nonSerializableFunctionFields = new ArrayList<>();
+        ArrayList<Field> nonSerializableFunctionFields = new ArrayList<>();
 
         List<Class<?>> nonSerializableClasses = new ArrayList<>();
         for (String className : classes) {
@@ -221,9 +220,7 @@ public class ClassesSerializableTest {
     private void failSerializableClasses(
             List<Class<?>> nonSerializableClasses) {
         String nonSerializableString = "";
-        Iterator<Class<?>> it = nonSerializableClasses.iterator();
-        while (it.hasNext()) {
-            Class<?> c = it.next();
+        for (Class<?> c : nonSerializableClasses) {
             nonSerializableString += ", " + c.getName();
             if (c.isAnonymousClass()) {
                 nonSerializableString += "(super: ";
diff --git a/server/src/test/java/com/vaadin/tests/server/component/grid/GridDetailsTest.java b/server/src/test/java/com/vaadin/tests/server/component/grid/GridDetailsTest.java
index c7f1fbd778..454b5d3b3d 100644
--- a/server/src/test/java/com/vaadin/tests/server/component/grid/GridDetailsTest.java
+++ b/server/src/test/java/com/vaadin/tests/server/component/grid/GridDetailsTest.java
@@ -54,10 +54,7 @@ public class GridDetailsTest {
 
     @Test
     public void testGridComponentIteratorContainsDetailsComponents() {
-        Iterator<Component> i = grid.iterator();
-
-        while (i.hasNext()) {
-            Component c = i.next();
+        for (Component c : grid) {
             if (c instanceof Label) {
                 String value = ((Label) c).getValue();
                 Assert.assertTrue(
diff --git a/server/src/test/java/com/vaadin/tests/server/components/ComponentAttachDetachListenerTest.java b/server/src/test/java/com/vaadin/tests/server/components/ComponentAttachDetachListenerTest.java
index b13a379b05..5f4f3cea65 100644
--- a/server/src/test/java/com/vaadin/tests/server/components/ComponentAttachDetachListenerTest.java
+++ b/server/src/test/java/com/vaadin/tests/server/components/ComponentAttachDetachListenerTest.java
@@ -7,8 +7,6 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 
-import java.util.Iterator;
-
 import org.junit.Before;
 import org.junit.Test;
 
@@ -63,9 +61,8 @@ public class ComponentAttachDetachListenerTest {
             attachTarget = event.getContainer();
 
             // Search for component in container (should be found)
-            Iterator<Component> iter = attachTarget.iterator();
-            while (iter.hasNext()) {
-                if (iter.next() == attachedComponent) {
+            for (Component c : attachTarget) {
+                if (c == attachedComponent) {
                     foundInContainer = true;
                     break;
                 }
@@ -93,9 +90,8 @@ public class ComponentAttachDetachListenerTest {
             detachedTarget = event.getContainer();
 
             // Search for component in container (should NOT be found)
-            Iterator<Component> iter = detachedTarget.iterator();
-            while (iter.hasNext()) {
-                if (iter.next() == detachedComponent) {
+            for (Component c : detachedTarget) {
+                if (c == detachedComponent) {
                     foundInContainer = true;
                     break;
                 }
diff --git a/uitest/src/main/java/com/vaadin/tests/TestBench.java b/uitest/src/main/java/com/vaadin/tests/TestBench.java
index 388a113768..2c5634ab32 100644
--- a/uitest/src/main/java/com/vaadin/tests/TestBench.java
+++ b/uitest/src/main/java/com/vaadin/tests/TestBench.java
@@ -21,7 +21,6 @@ import java.net.URL;
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Set;
 
@@ -138,9 +137,7 @@ public class TestBench extends com.vaadin.server.LegacyApplication
                             // try to find a proper test class
 
                             // exact match
-                            Iterator<?> iterator = menu.getItemIds().iterator();
-                            while (iterator.hasNext()) {
-                                Object next = iterator.next();
+                            for (Object next : menu.getItemIds()) {
                                 if (next instanceof Class) {
                                     Class<?> c = (Class<?>) next;
                                     String string = c.getName();
@@ -153,9 +150,7 @@ public class TestBench extends com.vaadin.server.LegacyApplication
                             }
 
                             // simple name match
-                            iterator = menu.getItemIds().iterator();
-                            while (iterator.hasNext()) {
-                                Object next = iterator.next();
+                            for (Object next : menu.getItemIds()) {
                                 if (next instanceof Class) {
                                     Class<?> c = (Class<?>) next;
                                     String string = c.getSimpleName();
@@ -167,9 +162,7 @@ public class TestBench extends com.vaadin.server.LegacyApplication
                                 }
                             }
                             // ticket match
-                            iterator = menu.getItemIds().iterator();
-                            while (iterator.hasNext()) {
-                                Object next = iterator.next();
+                            for (Object next : menu.getItemIds()) {
                                 if (next instanceof Class) {
                                     Class<?> c = (Class<?>) next;
                                     String string = c.getSimpleName();
@@ -183,9 +176,7 @@ public class TestBench extends com.vaadin.server.LegacyApplication
                             }
 
                             // just partly mach lowercase
-                            iterator = menu.getItemIds().iterator();
-                            while (iterator.hasNext()) {
-                                Object next = iterator.next();
+                            for (Object next : menu.getItemIds()) {
                                 if (next instanceof Class) {
                                     Class<?> c = (Class<?>) next;
                                     String string = c.getSimpleName();
@@ -200,9 +191,7 @@ public class TestBench extends com.vaadin.server.LegacyApplication
 
                             getMainWindow().showNotification(
                                     "No potential matc for #" + fragment);
-
                         }
-
                     }
                 });
 
diff --git a/uitest/src/main/java/com/vaadin/tests/components/accordion/RemoveTabs.java b/uitest/src/main/java/com/vaadin/tests/components/accordion/RemoveTabs.java
index 7ca7185500..c86d1b2682 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/accordion/RemoveTabs.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/accordion/RemoveTabs.java
@@ -1,7 +1,6 @@
 package com.vaadin.tests.components.accordion;
 
 import java.util.ArrayList;
-import java.util.Iterator;
 import java.util.List;
 
 import com.vaadin.tests.components.TestBase;
@@ -96,11 +95,9 @@ public class RemoveTabs extends TestBase {
     }
 
     private void closeLastTab() {
-        Iterator<Component> i = accordion.iterator();
         Component last = null;
-        while (i.hasNext()) {
-            last = i.next();
-
+        for (Component c : accordion) {
+            last = c;
         }
         accordion.removeComponent(last);
     }
@@ -110,9 +107,7 @@ public class RemoveTabs extends TestBase {
 
         if (container != null) {
             List<Component> c = new ArrayList<>();
-            Iterator<Component> i = container.iterator();
-            while (i.hasNext()) {
-                Component comp = i.next();
+            for (Component comp : container) {
                 c.add(comp);
             }
             container.removeAllComponents();
diff --git a/uitest/src/main/java/com/vaadin/tests/components/composite/CompositeChainUI.java b/uitest/src/main/java/com/vaadin/tests/components/composite/CompositeChainUI.java
index 481f7c958f..bfb3bf0bfc 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/composite/CompositeChainUI.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/composite/CompositeChainUI.java
@@ -82,10 +82,9 @@ public class CompositeChainUI extends AbstractTestUIWithLog {
         String msg = component.getClass().getSimpleName();
         if (component instanceof HasComponents) {
 
-            Iterator<Component> iterator = ((HasComponents) component)
-                    .iterator();
-            if (iterator.hasNext()) {
-                Component content = iterator.next();
+            Iterator<Component> it = ((HasComponents) component).iterator();
+            if (it.hasNext()) {
+                Component content = it.next();
                 if (content != null) {
                     msg += " -> " + getHierarchy(content);
                 }
diff --git a/uitest/src/main/java/com/vaadin/tests/components/tabsheet/RemoveTabs.java b/uitest/src/main/java/com/vaadin/tests/components/tabsheet/RemoveTabs.java
index 3dd2d0cd0a..4a04ff669c 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/tabsheet/RemoveTabs.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/tabsheet/RemoveTabs.java
@@ -1,7 +1,6 @@
 package com.vaadin.tests.components.tabsheet;
 
 import java.util.ArrayList;
-import java.util.Iterator;
 import java.util.List;
 
 import com.vaadin.tests.components.TestBase;
@@ -120,11 +119,9 @@ public class RemoveTabs extends TestBase {
     }
 
     private void closeLastTab() {
-        Iterator<Component> i = tabsheet.getComponentIterator();
         Component last = null;
-        while (i.hasNext()) {
-            last = i.next();
-
+        for (Component c : tabsheet) {
+            last = c;
         }
         tabsheet.removeComponent(last);
     }
@@ -134,9 +131,7 @@ public class RemoveTabs extends TestBase {
 
         if (container != null) {
             List<Component> c = new ArrayList<>();
-            Iterator<Component> i = container.getComponentIterator();
-            while (i.hasNext()) {
-                Component comp = i.next();
+            for (Component comp : container) {
                 c.add(comp);
             }
             container.removeAllComponents();
diff --git a/uitest/src/main/java/com/vaadin/tests/urifragments/FragmentHandlingAndAsynchUIUpdate.java b/uitest/src/main/java/com/vaadin/tests/urifragments/FragmentHandlingAndAsynchUIUpdate.java
index b808a3d973..bdc021868d 100644
--- a/uitest/src/main/java/com/vaadin/tests/urifragments/FragmentHandlingAndAsynchUIUpdate.java
+++ b/uitest/src/main/java/com/vaadin/tests/urifragments/FragmentHandlingAndAsynchUIUpdate.java
@@ -1,7 +1,5 @@
 package com.vaadin.tests.urifragments;
 
-import java.util.Iterator;
-
 import com.vaadin.server.Page;
 import com.vaadin.server.Page.UriFragmentChangedEvent;
 import com.vaadin.server.Page.UriFragmentChangedListener;
@@ -62,12 +60,10 @@ public class FragmentHandlingAndAsynchUIUpdate extends AbstractTestUIWithLog {
                     return;
                 }
 
-                Iterator<Component> it = getLayout().iterator();
                 final String frag = event.getUriFragment().substring(4);
 
                 Component fragComp = null;
-                while (it.hasNext()) {
-                    Component comp = it.next();
+                for (Component comp : getLayout()) {
                     if (comp.getId() != null && comp instanceof Label
                             && comp.getId().equals(frag)) {
                         fragComp = comp;