Use .toLowerCase and .toUpperCase(Locale.ROOT) (#10182)

* Use .toLowerCase and .toUpperCase(Locale.ROOT)

* Spaces

* add spaces after if(

39 files changed, 223 insertions, 162 deletions

diff --git a/uitest/src/main/java/com/vaadin/launcher/util/BrowserLauncher.java b/uitest/src/main/java/com/vaadin/launcher/util/BrowserLauncher.java
index cf26d4a891..5abc77e3ff 100644
--- a/uitest/src/main/java/com/vaadin/launcher/util/BrowserLauncher.java
+++ b/uitest/src/main/java/com/vaadin/launcher/util/BrowserLauncher.java
@@ -21,6 +21,7 @@ import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.util.Locale;
 
 /**
  * This class opens default browser for DemoLauncher class. Default browser is
@@ -40,7 +41,7 @@ public class BrowserLauncher {
         boolean started = false;
 
         final String os = System.getProperty("os.name", "windows")
-                .toLowerCase();
+                .toLowerCase(Locale.ROOT);
 
         // Linux
         if (os.indexOf("linux") >= 0) {
diff --git a/uitest/src/main/java/com/vaadin/tests/TestBench.java b/uitest/src/main/java/com/vaadin/tests/TestBench.java
index b7b8c93177..208f583dc3 100644
--- a/uitest/src/main/java/com/vaadin/tests/TestBench.java
+++ b/uitest/src/main/java/com/vaadin/tests/TestBench.java
@@ -22,6 +22,7 @@ import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Set;
 
 import com.vaadin.server.ExternalResource;
@@ -180,8 +181,9 @@ public class TestBench extends com.vaadin.server.LegacyApplication
                                 if (next instanceof Class) {
                                     Class<?> c = (Class<?>) next;
                                     String string = c.getSimpleName();
-                                    if (string.toLowerCase()
-                                            .contains(fragment.toLowerCase())) {
+                                    if (string.toLowerCase(Locale.ROOT)
+                                            .contains(fragment.toLowerCase(
+                                                    Locale.ROOT))) {
                                         menu.setValue(c);
                                         mainLayout.setSplitPosition(0);
                                         return;
diff --git a/uitest/src/main/java/com/vaadin/tests/components/combobox/ComboBoxItemIcon.java b/uitest/src/main/java/com/vaadin/tests/components/combobox/ComboBoxItemIcon.java
index a479922b4d..ad27e2b6ab 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/combobox/ComboBoxItemIcon.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/combobox/ComboBoxItemIcon.java
@@ -1,5 +1,7 @@
 package com.vaadin.tests.components.combobox;
 
+import java.util.Locale;
+
 import com.vaadin.server.ThemeResource;
 import com.vaadin.tests.components.TestBase;
 import com.vaadin.ui.ComboBox;
@@ -21,8 +23,9 @@ public class ComboBoxItemIcon extends TestBase {
         {
             ComboBox<String> cb = new ComboBox<>();
             cb.setItems("FI", "SE");
-            cb.setItemIconGenerator(item -> new ThemeResource(
-                    "../tests-tickets/icons/" + item.toLowerCase() + ".gif"));
+            cb.setItemIconGenerator(
+                    item -> new ThemeResource("../tests-tickets/icons/"
+                            + item.toLowerCase(Locale.ROOT) + ".gif"));
 
             addComponent(cb);
         }
@@ -31,7 +34,8 @@ public class ComboBoxItemIcon extends TestBase {
             cb.setItems("Finland", "Australia", "Hungary");
             cb.setItemIconGenerator(
                     item -> new ThemeResource("../tests-tickets/icons/"
-                            + item.substring(0, 2).toLowerCase() + ".gif"));
+                            + item.substring(0, 2).toLowerCase(Locale.ROOT)
+                            + ".gif"));
 
             cb.setValue("Hungary");
             addComponent(cb);
diff --git a/uitest/src/main/java/com/vaadin/tests/components/datefield/DateFieldChangeResolution.java b/uitest/src/main/java/com/vaadin/tests/components/datefield/DateFieldChangeResolution.java
index 3e04594de3..f03c6cb54f 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/datefield/DateFieldChangeResolution.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/datefield/DateFieldChangeResolution.java
@@ -15,6 +15,8 @@
  */
 package com.vaadin.tests.components.datefield;
 
+import java.util.Locale;
+
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.shared.ui.datefield.DateResolution;
 import com.vaadin.tests.components.AbstractReindeerTestUI;
@@ -42,13 +44,12 @@ public class DateFieldChangeResolution extends AbstractReindeerTestUI {
         HorizontalLayout hlayout = new HorizontalLayout();
         addComponent(hlayout);
         for (final DateResolution value : DateResolution.values()) {
-            String resolutionString = value.toString().toLowerCase();
+            String resolutionString = value.toString().toLowerCase(Locale.ROOT);
             Button button = new Button(resolutionString);
             button.addClickListener(event -> dateField.setResolution(value));
             button.setId(BUTTON_BASE_ID + resolutionString);
             hlayout.addComponent(button);
         }
-
     }
 
     @Override
diff --git a/uitest/src/main/java/com/vaadin/tests/components/datefield/DateTimeFieldChangeResolution.java b/uitest/src/main/java/com/vaadin/tests/components/datefield/DateTimeFieldChangeResolution.java
index 2bf161daf4..2a14e20467 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/datefield/DateTimeFieldChangeResolution.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/datefield/DateTimeFieldChangeResolution.java
@@ -15,6 +15,8 @@
  */
 package com.vaadin.tests.components.datefield;
 
+import java.util.Locale;
+
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.shared.ui.datefield.DateTimeResolution;
 import com.vaadin.tests.components.AbstractReindeerTestUI;
@@ -41,13 +43,12 @@ public class DateTimeFieldChangeResolution extends AbstractReindeerTestUI {
         HorizontalLayout hlayout = new HorizontalLayout();
         addComponent(hlayout);
         for (final DateTimeResolution value : DateTimeResolution.values()) {
-            String resolutionString = value.toString().toLowerCase();
+            String resolutionString = value.toString().toLowerCase(Locale.ROOT);
             Button button = new Button(resolutionString);
             button.addClickListener(event -> dateField.setResolution(value));
             button.setId(BUTTON_BASE_ID + resolutionString);
             hlayout.addComponent(button);
         }
-
     }
 
     @Override
diff --git a/uitest/src/main/java/com/vaadin/tests/components/grid/GridComponents.java b/uitest/src/main/java/com/vaadin/tests/components/grid/GridComponents.java
index 92ba75869c..c8f7127f76 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/grid/GridComponents.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/grid/GridComponents.java
@@ -1,6 +1,7 @@
 package com.vaadin.tests.components.grid;
 
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 import java.util.stream.IntStream;
 
@@ -54,7 +55,7 @@ public class GridComponents extends AbstractTestUIWithLog {
                     e -> Notification.show(
                             "Clicked button on row for: " + string,
                             Type.WARNING_MESSAGE));
-            button.setId(string.replace(' ', '_').toLowerCase());
+            button.setId(string.replace(' ', '_').toLowerCase(Locale.ROOT));
             return button;
         }, new ComponentRenderer()).setId("button").setCaption("Button");
         // make sure the buttons and focus outlines fit completely in a row
diff --git a/uitest/src/main/java/com/vaadin/tests/components/grid/GridEditorUI.java b/uitest/src/main/java/com/vaadin/tests/components/grid/GridEditorUI.java
index 400ff5266c..6da0a3757f 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/grid/GridEditorUI.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/grid/GridEditorUI.java
@@ -18,6 +18,7 @@ package com.vaadin.tests.components.grid;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Locale;
 import java.util.Random;
 
 import com.vaadin.server.VaadinRequest;
@@ -51,8 +52,9 @@ public class GridEditorUI extends AbstractReindeerTestUIWithLog {
             person.setFirstName(TestDataGenerator.getFirstName(r));
             person.setLastName(TestDataGenerator.getLastName(r));
             person.getAddress().setCity(TestDataGenerator.getCity(r));
-            person.setEmail(person.getFirstName().toLowerCase() + "."
-                    + person.getLastName().toLowerCase() + "@vaadin.com");
+            person.setEmail(person.getFirstName().toLowerCase(Locale.ROOT) + "."
+                    + person.getLastName().toLowerCase(Locale.ROOT)
+                    + "@vaadin.com");
             person.setPhoneNumber(TestDataGenerator.getPhoneNumber(r));
 
             person.getAddress()
diff --git a/uitest/src/main/java/com/vaadin/tests/components/table/HeaderRightClickAfterDrag.java b/uitest/src/main/java/com/vaadin/tests/components/table/HeaderRightClickAfterDrag.java
index b4bc32ab7b..84c676b878 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/table/HeaderRightClickAfterDrag.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/table/HeaderRightClickAfterDrag.java
@@ -1,5 +1,7 @@
 package com.vaadin.tests.components.table;
 
+import java.util.Locale;
+
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.shared.MouseEventDetails;
 import com.vaadin.shared.ui.ContentMode;
@@ -26,10 +28,11 @@ public class HeaderRightClickAfterDrag extends AbstractReindeerTestUI {
             public void headerClick(Table.HeaderClickEvent event) {
                 if (MouseEventDetails.MouseButton.RIGHT
                         .equals(event.getButton())) {
-                    Window window = new Window("Right-clicked:", new Label(
-                            "<center>" + event.getPropertyId().toString()
-                                    .toUpperCase() + "</center>",
-                            ContentMode.HTML));
+                    Window window = new Window("Right-clicked:",
+                            new Label("<center>"
+                                    + event.getPropertyId().toString()
+                                            .toUpperCase(Locale.ROOT)
+                                    + "</center>", ContentMode.HTML));
                     window.setPositionX(event.getClientX());
                     window.setPositionY(event.getClientY());
                     window.setResizable(false);
diff --git a/uitest/src/main/java/com/vaadin/tests/components/textfield/TextFieldsValueChangeMode.java b/uitest/src/main/java/com/vaadin/tests/components/textfield/TextFieldsValueChangeMode.java
index 71b0a801b6..8445d8e5c9 100644
--- a/uitest/src/main/java/com/vaadin/tests/components/textfield/TextFieldsValueChangeMode.java
+++ b/uitest/src/main/java/com/vaadin/tests/components/textfield/TextFieldsValueChangeMode.java
@@ -1,5 +1,7 @@
 package com.vaadin.tests.components.textfield;
 
+import java.util.Locale;
+
 import com.vaadin.data.HasValue.ValueChangeEvent;
 import com.vaadin.server.VaadinRequest;
 import com.vaadin.shared.ui.ValueChangeMode;
@@ -29,7 +31,7 @@ public class TextFieldsValueChangeMode extends AbstractTestUIWithLog {
 
     private Component createFields(Class<?> fieldClass) {
         VerticalLayout vl = new VerticalLayout();
-        String id = fieldClass.getSimpleName().toLowerCase();
+        String id = fieldClass.getSimpleName().toLowerCase(Locale.ROOT);
         try {
             AbstractField<String> f = (AbstractField<String>) fieldClass
                     .newInstance();
diff --git a/uitest/src/main/java/com/vaadin/tests/containers/TestItemSorter.java b/uitest/src/main/java/com/vaadin/tests/containers/TestItemSorter.java
index 4af48db20a..0c6da38a1e 100644
--- a/uitest/src/main/java/com/vaadin/tests/containers/TestItemSorter.java
+++ b/uitest/src/main/java/com/vaadin/tests/containers/TestItemSorter.java
@@ -2,6 +2,7 @@ package com.vaadin.tests.containers;
 
 import java.util.Collection;
 import java.util.Comparator;
+import java.util.Locale;
 
 import com.vaadin.tests.components.TestBase;
 import com.vaadin.ui.Button;
@@ -33,13 +34,15 @@ public class TestItemSorter extends TestBase {
                     Boolean b1 = ((CheckBox) o1).getValue();
                     return b1.compareTo(((CheckBox) o2).getValue());
                 } else if (o1 instanceof Button && o2 instanceof Button) {
-                    String caption1 = ((Button) o1).getCaption().toLowerCase();
-                    String caption2 = ((Button) o2).getCaption().toLowerCase();
+                    String caption1 = ((Button) o1).getCaption()
+                            .toLowerCase(Locale.ROOT);
+                    String caption2 = ((Button) o2).getCaption()
+                            .toLowerCase(Locale.ROOT);
                     return caption1.compareTo(caption2);
 
                 } else if (o1 instanceof String && o2 instanceof String) {
-                    return ((String) o1).toLowerCase()
-                            .compareTo(((String) o2).toLowerCase());
+                    return ((String) o1).toLowerCase(Locale.ROOT)
+                            .compareTo(((String) o2).toLowerCase(Locale.ROOT));
                 }
 
                 return 0;
@@ -54,8 +57,8 @@ public class TestItemSorter extends TestBase {
 
     private static void populateContainer(IndexedContainer container) {
         container.removeAllItems();
-        String[] strings = { "Text 1", "Text 2", "true", "false",
-                "Caption 1", "Caption 2" };
+        String[] strings = { "Text 1", "Text 2", "true", "false", "Caption 1",
+                "Caption 2" };
         for (String s : strings) {
             Object id = container.addItem();
             Item item = container.getItem(id);
diff --git a/uitest/src/main/java/com/vaadin/tests/themes/ButtonsTest.java b/uitest/src/main/java/com/vaadin/tests/themes/ButtonsTest.java
index 76bdb6cd13..5c42c445c0 100644
--- a/uitest/src/main/java/com/vaadin/tests/themes/ButtonsTest.java
+++ b/uitest/src/main/java/com/vaadin/tests/themes/ButtonsTest.java
@@ -1,5 +1,7 @@
 package com.vaadin.tests.themes;
 
+import java.util.Locale;
+
 import com.vaadin.server.ThemeResource;
 import com.vaadin.server.UserError;
 import com.vaadin.ui.Button;
@@ -125,7 +127,7 @@ public class ButtonsTest extends com.vaadin.server.LegacyApplication {
             } else {
                 b = new Button(style + " style");
             }
-            b.setStyleName(style.toLowerCase());
+            b.setStyleName(style.toLowerCase(Locale.ROOT));
             if (icon) {
                 b.setIcon(new ThemeResource("../runo/icons/"
                         + (largeIcons ? "64" : "16") + "/document.png"));
diff --git a/uitest/src/main/java/com/vaadin/tests/themes/valo/CommonParts.java b/uitest/src/main/java/com/vaadin/tests/themes/valo/CommonParts.java
index 4c83430832..b5cb23a867 100644
--- a/uitest/src/main/java/com/vaadin/tests/themes/valo/CommonParts.java
+++ b/uitest/src/main/java/com/vaadin/tests/themes/valo/CommonParts.java
@@ -15,6 +15,8 @@
  */
 package com.vaadin.tests.themes.valo;
 
+import java.util.Locale;
+
 import com.vaadin.event.ShortcutAction.KeyCode;
 import com.vaadin.icons.VaadinIcons;
 import com.vaadin.navigator.View;
@@ -185,7 +187,8 @@ public class CommonParts extends VerticalLayout implements View {
                             typeString = "";
                             notification.setStyleName(styleString.trim());
                         } else {
-                            typeString = selectedItem.getText().toLowerCase();
+                            typeString = selectedItem.getText()
+                                    .toLowerCase(Locale.ROOT);
                             notification.setStyleName(
                                     (typeString + " " + styleString.trim())
                                             .trim());
@@ -214,8 +217,8 @@ public class CommonParts extends VerticalLayout implements View {
                         styleString = "";
                         for (MenuItem item : style.getItems()) {
                             if (item.isChecked()) {
-                                styleString += " "
-                                        + item.getText().toLowerCase();
+                                styleString += " " + item.getText()
+                                        .toLowerCase(Locale.ROOT);
                             }
                         }
                         if (!styleString.trim().isEmpty()) {
@@ -603,7 +606,8 @@ public class CommonParts extends VerticalLayout implements View {
                         if (selectedItem.getText()
                                 .equals("Borderless Toolbars")) {
                             toolbarStyle = selectedItem.isChecked()
-                                    ? ValoTheme.MENUBAR_BORDERLESS : null;
+                                    ? ValoTheme.MENUBAR_BORDERLESS
+                                    : null;
                         }
 
                         win.setContent(windowContent());
@@ -638,8 +642,9 @@ public class CommonParts extends VerticalLayout implements View {
                     @Override
                     public void menuSelected(MenuItem selectedItem) {
                         if (selectedItem.getText().equals("Caption")) {
-                            win.setCaption(selectedItem.isChecked()
-                                    ? "Window Caption" : null);
+                            win.setCaption(
+                                    selectedItem.isChecked() ? "Window Caption"
+                                            : null);
                         } else if (selectedItem.getText().equals("Closable")) {
                             win.setClosable(selectedItem.isChecked());
                         } else if (selectedItem.getText().equals("Resizable")) {
diff --git a/uitest/src/main/java/com/vaadin/tests/util/PersonContainer.java b/uitest/src/main/java/com/vaadin/tests/util/PersonContainer.java
index bdb73234ba..2ac37a07f7 100644
--- a/uitest/src/main/java/com/vaadin/tests/util/PersonContainer.java
+++ b/uitest/src/main/java/com/vaadin/tests/util/PersonContainer.java
@@ -4,6 +4,7 @@ import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Locale;
 import java.util.Random;
 
 import com.vaadin.v7.data.util.BeanItemContainer;
@@ -56,8 +57,8 @@ public class PersonContainer extends BeanItemContainer<Person>
             p.setFirstName(TestDataGenerator.getFirstName(r));
             p.setLastName(TestDataGenerator.getLastName(r));
             p.getAddress().setCity(TestDataGenerator.getCity(r));
-            p.setEmail(p.getFirstName().toLowerCase() + "."
-                    + p.getLastName().toLowerCase() + "@vaadin.com");
+            p.setEmail(p.getFirstName().toLowerCase(Locale.ROOT) + "."
+                    + p.getLastName().toLowerCase(Locale.ROOT) + "@vaadin.com");
             p.setPhoneNumber(TestDataGenerator.getPhoneNumber(r));
 
             p.getAddress().setPostalCode(TestDataGenerator.getPostalCode(r));
diff --git a/uitest/src/main/java/com/vaadin/tests/widgetset/client/SerializerTestConnector.java b/uitest/src/main/java/com/vaadin/tests/widgetset/client/SerializerTestConnector.java
index 797aed66cb..037fc049a8 100644
--- a/uitest/src/main/java/com/vaadin/tests/widgetset/client/SerializerTestConnector.java
+++ b/uitest/src/main/java/com/vaadin/tests/widgetset/client/SerializerTestConnector.java
@@ -23,6 +23,7 @@ import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
@@ -169,8 +170,8 @@ public class SerializerTestConnector extends AbstractExtensionConnector {
             public void sendChar(char value, Character boxedValue,
                     char[] array) {
                 rpc.sendChar(Character.toUpperCase(boxedValue.charValue()),
-                        Character.valueOf(value),
-                        new String(array).toLowerCase().toCharArray());
+                        Character.valueOf(value), new String(array)
+                                .toLowerCase(Locale.ROOT).toCharArray());
             }
 
             @Override
diff --git a/uitest/src/main/java/com/vaadin/v7/tests/components/textfield/TextChangeEvents2.java b/uitest/src/main/java/com/vaadin/v7/tests/components/textfield/TextChangeEvents2.java
index 4dd7dfd527..7e32692e58 100644
--- a/uitest/src/main/java/com/vaadin/v7/tests/components/textfield/TextChangeEvents2.java
+++ b/uitest/src/main/java/com/vaadin/v7/tests/components/textfield/TextChangeEvents2.java
@@ -1,5 +1,7 @@
 package com.vaadin.v7.tests.components.textfield;
 
+import java.util.Locale;
+
 import com.vaadin.event.FieldEvents.BlurEvent;
 import com.vaadin.event.FieldEvents.BlurListener;
 import com.vaadin.event.FieldEvents.FocusEvent;
@@ -108,7 +110,7 @@ public class TextChangeEvents2 extends TestBase {
 
                 @Override
                 public void textChange(TextChangeEvent event) {
-                    tf.setValue(event.getText().toUpperCase());
+                    tf.setValue(event.getText().toUpperCase(Locale.ROOT));
                 }
             });
 
@@ -122,8 +124,8 @@ public class TextChangeEvents2 extends TestBase {
         }
 
         {
-            final TextField[] tfs = { new TextField(),
-                    new TextField(), new TextField(), new TextField() };
+            final TextField[] tfs = { new TextField(), new TextField(),
+                    new TextField(), new TextField() };
             HorizontalLayout hl = new HorizontalLayout();
             hl.setCaption("Blää");
             getLayout().addComponent(hl);
diff --git a/uitest/src/test/java/com/vaadin/tests/binder/BinderValidatorErrorLevelTest.java b/uitest/src/test/java/com/vaadin/tests/binder/BinderValidatorErrorLevelTest.java
index 4be9f9a49e..20b788a125 100644
--- a/uitest/src/test/java/com/vaadin/tests/binder/BinderValidatorErrorLevelTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/binder/BinderValidatorErrorLevelTest.java
@@ -1,6 +1,7 @@
 package com.vaadin.tests.binder;
 
 import java.io.IOException;
+import java.util.Locale;
 
 import org.junit.Assert;
 import org.junit.Test;
@@ -22,20 +23,23 @@ public class BinderValidatorErrorLevelTest extends SingleBrowserTest {
 
             // Screenshot the whole slot
             compareScreen(textField.findElement(By.xpath("..")),
-                    l.name().toLowerCase());
+                    l.name().toLowerCase(Locale.ROOT));
 
             Assert.assertTrue("Error style for " + l.name() + " not present",
-                    textField.getAttribute("class").contains(
-                            "v-textfield-error-" + l.name().toLowerCase()));
+                    textField.getAttribute("class")
+                            .contains("v-textfield-error-"
+                                    + l.name().toLowerCase(Locale.ROOT)));
             textField.setValue("long enough text");
             Assert.assertFalse("Error style for " + l.name() + " still present",
-                    textField.getAttribute("class").contains(
-                            "v-textfield-error-" + l.name().toLowerCase()));
+                    textField.getAttribute("class")
+                            .contains("v-textfield-error-"
+                                    + l.name().toLowerCase(Locale.ROOT)));
             textField.setValue("foo");
             Assert.assertTrue(
                     "Error style for " + l.name() + " should be present again.",
-                    textField.getAttribute("class").contains(
-                            "v-textfield-error-" + l.name().toLowerCase()));
+                    textField.getAttribute("class")
+                            .contains("v-textfield-error-"
+                                    + l.name().toLowerCase(Locale.ROOT)));
         }
     }
 }
diff --git a/uitest/src/test/java/com/vaadin/tests/components/ErrorLevelsTest.java b/uitest/src/test/java/com/vaadin/tests/components/ErrorLevelsTest.java
index 2dc9e02914..647c9601e4 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/ErrorLevelsTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/ErrorLevelsTest.java
@@ -6,6 +6,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
+import java.util.Locale;
 
 import org.junit.Test;
 import org.openqa.selenium.Keys;
@@ -133,7 +134,7 @@ public class ErrorLevelsTest extends SingleBrowserTest {
 
     private String getErrorLevelClassName(String prefix,
             ErrorLevel errorLevel) {
-        return prefix + "-" + errorLevel.toString().toLowerCase();
+        return prefix + "-" + errorLevel.toString().toLowerCase(Locale.ROOT);
     }
 
     private List<String> getErrorLevelClassNames(String prefix,
@@ -147,7 +148,8 @@ public class ErrorLevelsTest extends SingleBrowserTest {
 
     private void selectErrorLevel(ErrorLevel errorLevel) {
         errorLevelSelector.clear();
-        errorLevelSelector.sendKeys(errorLevel.toString().toLowerCase());
+        errorLevelSelector
+                .sendKeys(errorLevel.toString().toLowerCase(Locale.ROOT));
         errorLevelSelector.sendKeys(getReturn());
     }
 
diff --git a/uitest/src/test/java/com/vaadin/tests/components/checkboxgroup/CheckBoxGroupTest.java b/uitest/src/test/java/com/vaadin/tests/components/checkboxgroup/CheckBoxGroupTest.java
index 36367e4b66..b5883d43b9 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/checkboxgroup/CheckBoxGroupTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/checkboxgroup/CheckBoxGroupTest.java
@@ -24,6 +24,7 @@ import static org.junit.Assert.assertTrue;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Locale;
 import java.util.stream.Collectors;
 
 import org.junit.Before;
@@ -260,11 +261,11 @@ public class CheckBoxGroupTest extends MultiBrowserTest {
         for (int i = 0; i < optionsCssClasses.size(); i++) {
             String cssClassList = optionsCssClasses.get(i);
             if (i == 10) {
-                assertTrue("10th item should be disabled",
-                        cssClassList.toLowerCase().contains("disabled"));
+                assertTrue("10th item should be disabled", cssClassList
+                        .toLowerCase(Locale.ROOT).contains("disabled"));
             } else {
-                assertFalse("Only 10th item should be disabled",
-                        cssClassList.toLowerCase().contains("disabled"));
+                assertFalse("Only 10th item should be disabled", cssClassList
+                        .toLowerCase(Locale.ROOT).contains("disabled"));
             }
         }
     }
diff --git a/uitest/src/test/java/com/vaadin/tests/components/grid/GridColspansTest.java b/uitest/src/test/java/com/vaadin/tests/components/grid/GridColspansTest.java
index 27b9e805bd..306e0cbe3f 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/grid/GridColspansTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/grid/GridColspansTest.java
@@ -57,14 +57,14 @@ public class GridColspansTest extends MultiBrowserTest {
 
         GridElement grid = $(GridElement.class).first();
         assertEquals("Failed initial condition.", "all the stuff",
-                grid.getHeaderCell(0, 1).getText().toLowerCase(Locale.ENGLISH));
+                grid.getHeaderCell(0, 1).getText().toLowerCase(Locale.ROOT));
         assertEquals("Failed initial condition.", "first name",
-                grid.getHeaderCell(2, 1).getText().toLowerCase(Locale.ENGLISH));
+                grid.getHeaderCell(2, 1).getText().toLowerCase(Locale.ROOT));
         $(ButtonElement.class).caption("Show/Hide firstName").first().click();
         assertEquals("Header text changed on column hide.", "all the stuff",
-                grid.getHeaderCell(0, 1).getText().toLowerCase(Locale.ENGLISH));
+                grid.getHeaderCell(0, 1).getText().toLowerCase(Locale.ROOT));
         assertEquals("Failed initial condition.", "last name",
-                grid.getHeaderCell(2, 1).getText().toLowerCase(Locale.ENGLISH));
+                grid.getHeaderCell(2, 1).getText().toLowerCase(Locale.ROOT));
     }
 
     @Test
@@ -74,17 +74,17 @@ public class GridColspansTest extends MultiBrowserTest {
         GridElement grid = $(GridElement.class).first();
 
         assertEquals("Failed initial condition.", "first name",
-                grid.getHeaderCell(2, 1).getText().toLowerCase(Locale.ENGLISH));
+                grid.getHeaderCell(2, 1).getText().toLowerCase(Locale.ROOT));
 
         $(ButtonElement.class).caption("Show/Hide firstName").first().click();
 
         assertEquals("Failed initial condition.", "last name",
-                grid.getHeaderCell(2, 1).getText().toLowerCase(Locale.ENGLISH));
+                grid.getHeaderCell(2, 1).getText().toLowerCase(Locale.ROOT));
 
         $(ButtonElement.class).caption("Show/Hide firstName").first().click();
 
         assertEquals("Failed to find first name in last column", "first name",
-                grid.getHeaderCell(2, 5).getText().toLowerCase(Locale.ENGLISH));
+                grid.getHeaderCell(2, 5).getText().toLowerCase(Locale.ROOT));
 
     }
 
@@ -95,18 +95,18 @@ public class GridColspansTest extends MultiBrowserTest {
         GridElement grid = $(GridElement.class).first();
         GridCellElement headerCell = grid.getHeaderCell(1, 1);
         assertEquals("Failed initial condition.", "full name",
-                headerCell.getText().toLowerCase(Locale.ENGLISH));
+                headerCell.getText().toLowerCase(Locale.ROOT));
         assertEquals("Failed initial condition.", "first name",
-                grid.getHeaderCell(2, 1).getText().toLowerCase(Locale.ENGLISH));
+                grid.getHeaderCell(2, 1).getText().toLowerCase(Locale.ROOT));
         $(ButtonElement.class).get(1).click();
         headerCell = grid.getHeaderCell(1, 1);
         assertEquals("Joined Header text not changed on column reorder.",
-                "misc", headerCell.getText().toLowerCase(Locale.ENGLISH));
+                "misc", headerCell.getText().toLowerCase(Locale.ROOT));
         assertEquals("Unexpected colspan", "1",
                 headerCell.getAttribute("colspan"));
         headerCell = grid.getHeaderCell(1, 2);
         assertEquals("Header text not changed on column reorder", "full name",
-                headerCell.getText().toLowerCase(Locale.ENGLISH));
+                headerCell.getText().toLowerCase(Locale.ROOT));
         assertEquals("Unexpected colspan", "2",
                 headerCell.getAttribute("colspan"));
 
diff --git a/uitest/src/test/java/com/vaadin/tests/components/grid/GridComponentsTest.java b/uitest/src/test/java/com/vaadin/tests/components/grid/GridComponentsTest.java
index 88b218e6bf..4a303ddfb5 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/grid/GridComponentsTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/grid/GridComponentsTest.java
@@ -4,6 +4,7 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
+import java.util.Locale;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
 
@@ -142,7 +143,9 @@ public class GridComponentsTest extends MultiBrowserTest {
         GridRowElement row = $(GridElement.class).first().getRow(i);
         assertEquals("Label text did not match", string,
                 row.getCell(0).getText());
-        row.findElement(By.id(string.replace(' ', '_').toLowerCase())).click();
+        row.findElement(
+                By.id(string.replace(' ', '_').toLowerCase(Locale.ROOT)))
+                .click();
         // IE 11 is slow, need to wait for the notification.
         waitUntil(driver -> isElementPresent(NotificationElement.class), 10);
         assertTrue("Notification should contain given text",
diff --git a/uitest/src/test/java/com/vaadin/tests/components/grid/GridGeneratedPropertiesTest.java b/uitest/src/test/java/com/vaadin/tests/components/grid/GridGeneratedPropertiesTest.java
index df89f217f3..c2c28c75df 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/grid/GridGeneratedPropertiesTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/grid/GridGeneratedPropertiesTest.java
@@ -19,6 +19,8 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
+import java.util.Locale;
+
 import org.junit.Test;
 
 import com.vaadin.testbench.elements.GridElement;
@@ -35,7 +37,7 @@ public class GridGeneratedPropertiesTest extends MultiBrowserTest {
         openTestURL();
         GridElement grid = $(GridElement.class).first();
         assertEquals("Miles header wasn't present.", "miles",
-                grid.getHeaderCell(0, 2).getText().toLowerCase());
+                grid.getHeaderCell(0, 2).getText().toLowerCase(Locale.ROOT));
     }
 
     @Test
diff --git a/uitest/src/test/java/com/vaadin/tests/components/grid/GridMultiSelectionScrollBarTest.java b/uitest/src/test/java/com/vaadin/tests/components/grid/GridMultiSelectionScrollBarTest.java
index 93935f7524..4c4f4595c4 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/grid/GridMultiSelectionScrollBarTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/grid/GridMultiSelectionScrollBarTest.java
@@ -18,6 +18,7 @@ package com.vaadin.tests.components.grid;
 import static org.junit.Assert.assertTrue;
 
 import java.io.IOException;
+import java.util.Locale;
 
 import org.junit.Test;
 
@@ -33,7 +34,7 @@ public class GridMultiSelectionScrollBarTest extends MultiBrowserTest {
 
         assertTrue("Horizontal scrollbar should not be visible.",
                 $(GridElement.class).first().getHorizontalScroller()
-                        .getAttribute("style").toLowerCase()
+                        .getAttribute("style").toLowerCase(Locale.ROOT)
                         .contains("display: none;"));
 
         // Just to make sure nothing odd happened.
diff --git a/uitest/src/test/java/com/vaadin/tests/components/grid/basics/GridBasicsTest.java b/uitest/src/test/java/com/vaadin/tests/components/grid/basics/GridBasicsTest.java
index caec06b3f5..67c196a4e9 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/grid/basics/GridBasicsTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/grid/basics/GridBasicsTest.java
@@ -5,6 +5,7 @@ import static org.junit.Assert.assertTrue;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.stream.Stream;
 
 import org.junit.Before;
@@ -150,8 +151,8 @@ public abstract class GridBasicsTest extends MultiBrowserTest {
 
     protected void assertColumnHeader(String expectedHeaderCaption,
             TestBenchElement testBenchElement) {
-        assertEquals(expectedHeaderCaption.toLowerCase(),
-                testBenchElement.getText().toLowerCase());
+        assertEquals(expectedHeaderCaption.toLowerCase(Locale.ROOT),
+                testBenchElement.getText().toLowerCase(Locale.ROOT));
     }
 
     protected void assertColumnIsSorted(int index) {
@@ -199,7 +200,8 @@ public abstract class GridBasicsTest extends MultiBrowserTest {
         List<WebElement> elements = sidebar
                 .findElements(By.className("column-hiding-toggle"));
         for (WebElement e : elements) {
-            if (e.getText().toLowerCase().startsWith("column " + columnIndex)) {
+            if (e.getText().toLowerCase(Locale.ROOT)
+                    .startsWith("column " + columnIndex)) {
                 return e;
             }
         }
diff --git a/uitest/src/test/java/com/vaadin/tests/components/grid/basics/GridHeaderFooterTest.java b/uitest/src/test/java/com/vaadin/tests/components/grid/basics/GridHeaderFooterTest.java
index b7ba76ea73..322524fc76 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/grid/basics/GridHeaderFooterTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/grid/basics/GridHeaderFooterTest.java
@@ -20,6 +20,7 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 import java.util.List;
+import java.util.Locale;
 import java.util.stream.IntStream;
 
 import org.junit.Test;
@@ -157,7 +158,8 @@ public class GridHeaderFooterTest extends GridBasicsTest {
                 "Text Header");
         GridCellElement textCell = getGridElement().getHeaderCell(0, 2);
 
-        assertEquals("text header", textCell.getText().toLowerCase());
+        assertEquals("text header",
+                textCell.getText().toLowerCase(Locale.ROOT));
     }
 
     @Test
@@ -180,16 +182,16 @@ public class GridHeaderFooterTest extends GridBasicsTest {
         assertTrue("No notifications should've been shown",
                 !$(NotificationElement.class).exists());
         assertEquals("Header should've been reverted back to text header",
-                "text header",
-                getGridElement().getHeaderCell(0, 1).getText().toLowerCase());
+                "text header", getGridElement().getHeaderCell(0, 1).getText()
+                        .toLowerCase(Locale.ROOT));
     }
 
     @Test
     public void testColumnHidingToggleCaption_settingWidgetToHeader_toggleCaptionStays() {
         toggleColumnHidable(1);
         getSidebarOpenButton().click();
-        assertEquals("column 1",
-                getGridElement().getHeaderCell(0, 1).getText().toLowerCase());
+        assertEquals("column 1", getGridElement().getHeaderCell(0, 1).getText()
+                .toLowerCase(Locale.ROOT));
         assertEquals("Column 1", getColumnHidingToggle(1).getText());
 
         selectMenuPath("Component", "Columns", "Column 1", "Header Type",
@@ -218,7 +220,8 @@ public class GridHeaderFooterTest extends GridBasicsTest {
                 "Text Footer");
         GridCellElement textCell = getGridElement().getFooterCell(0, 2);
 
-        assertEquals("text footer", textCell.getText().toLowerCase());
+        assertEquals("text footer",
+                textCell.getText().toLowerCase(Locale.ROOT));
     }
 
     @Test
@@ -241,16 +244,16 @@ public class GridHeaderFooterTest extends GridBasicsTest {
         assertTrue("No notifications should've been shown",
                 !$(NotificationElement.class).exists());
         assertEquals("Footer should've been reverted back to text footer",
-                "text footer",
-                getGridElement().getFooterCell(0, 1).getText().toLowerCase());
+                "text footer", getGridElement().getFooterCell(0, 1).getText()
+                        .toLowerCase(Locale.ROOT));
     }
 
     @Test
     public void testColumnHidingToggleCaption_settingWidgetToFooter_toggleCaptionStays() {
         toggleColumnHidable(1);
         getSidebarOpenButton().click();
-        assertEquals("column 1",
-                getGridElement().getHeaderCell(0, 1).getText().toLowerCase());
+        assertEquals("column 1", getGridElement().getHeaderCell(0, 1).getText()
+                .toLowerCase(Locale.ROOT));
         assertEquals("Column 1", getColumnHidingToggle(1).getText());
 
         selectMenuPath("Component", "Columns", "Column 1", "Footer Type",
diff --git a/uitest/src/test/java/com/vaadin/tests/components/table/ColumnReorderingWithManyColumnsTest.java b/uitest/src/test/java/com/vaadin/tests/components/table/ColumnReorderingWithManyColumnsTest.java
index 98b10b9ce0..5e5773fc3f 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/table/ColumnReorderingWithManyColumnsTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/table/ColumnReorderingWithManyColumnsTest.java
@@ -3,6 +3,7 @@ package com.vaadin.tests.components.table;
 import static org.junit.Assert.assertEquals;
 
 import java.io.IOException;
+import java.util.Locale;
 
 import org.junit.Test;
 import org.openqa.selenium.By;
@@ -25,7 +26,7 @@ public class ColumnReorderingWithManyColumnsTest extends MultiBrowserTest {
                 .findElement(By.className("v-table-focus-slot-right"));
         String markedColumnName = markedElement.findElement(By.xpath(".."))
                 .getText();
-        assertEquals("col-9", markedColumnName.toLowerCase());
+        assertEquals("col-9", markedColumnName.toLowerCase(Locale.ROOT));
     }
 
     private void drag(WebElement source, WebElement target) {
diff --git a/uitest/src/test/java/com/vaadin/tests/components/ui/UIAutoGeneratedStyleNameTest.java b/uitest/src/test/java/com/vaadin/tests/components/ui/UIAutoGeneratedStyleNameTest.java
index 73dfc8f77e..3f7ab9c098 100644
--- a/uitest/src/test/java/com/vaadin/tests/components/ui/UIAutoGeneratedStyleNameTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/components/ui/UIAutoGeneratedStyleNameTest.java
@@ -39,7 +39,7 @@ public class UIAutoGeneratedStyleNameTest extends MultiBrowserTest {
         assertTrue("UI div element doesn't contain autogenerated style name",
                 containsStyle(getDriver().findElement(By.className("v-app")),
                         UIAutoGeneratedStyleName.class.getSimpleName()
-                                .toLowerCase(Locale.ENGLISH)));
+                                .toLowerCase(Locale.ROOT)));
 
         assertTrue(
                 "Overlays div element doesn't contain autogenerated style name",
@@ -47,7 +47,7 @@ public class UIAutoGeneratedStyleNameTest extends MultiBrowserTest {
                         getDriver().findElement(
                                 By.className("v-overlay-container")),
                         UIAutoGeneratedStyleName.class.getSimpleName()
-                                .toLowerCase(Locale.ENGLISH)));
+                                .toLowerCase(Locale.ROOT)));
     }
 
     private boolean containsStyle(WebElement element, String style) {
diff --git a/uitest/src/test/java/com/vaadin/tests/fieldgroup/BasicCrudGridEditorRowTest.java b/uitest/src/test/java/com/vaadin/tests/fieldgroup/BasicCrudGridEditorRowTest.java
index f23f087b40..655d046166 100644
--- a/uitest/src/test/java/com/vaadin/tests/fieldgroup/BasicCrudGridEditorRowTest.java
+++ b/uitest/src/test/java/com/vaadin/tests/fieldgroup/BasicCrudGridEditorRowTest.java
@@ -19,6 +19,8 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;
 
+import java.util.Locale;
+
 import org.junit.Before;
 import org.junit.Test;
 import org.openqa.selenium.By;
@@ -105,7 +107,8 @@ public class BasicCrudGridEditorRowTest extends MultiBrowserTest {
         // Open editor row
         new Actions(getDriver()).doubleClick(cell).perform();
 
-        String attribute = grid.getEditor().getAttribute("style").toLowerCase();
+        String attribute = grid.getEditor().getAttribute("style")
+                .toLowerCase(Locale.ROOT);
         assertFalse("Style should not contain top.",
                 attribute.contains("top:"));
     }
diff --git a/uitest/src/test/java/com/vaadin/tests/tb3/AffectedTB3TestLocator.java b/uitest/src/test/java/com/vaadin/tests/tb3/AffectedTB3TestLocator.java
index 9f8a79859d..016a246d40 100644
--- a/uitest/src/test/java/com/vaadin/tests/tb3/AffectedTB3TestLocator.java
+++ b/uitest/src/test/java/com/vaadin/tests/tb3/AffectedTB3TestLocator.java
@@ -19,6 +19,7 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Set;
 
 public class AffectedTB3TestLocator extends TB3TestLocator {
@@ -65,7 +66,8 @@ public class AffectedTB3TestLocator extends TB3TestLocator {
             String lastPart = packageParts[packageParts.length - 2];
 
             for (String f : affectedFiles) {
-                if (f.toLowerCase().contains(lastPart.toLowerCase())) {
+                if (f.toLowerCase(Locale.ROOT)
+                        .contains(lastPart.toLowerCase(Locale.ROOT))) {
                     affectedTestClasses.add(c);
 
                     // Break here not to accidentally add the same test class
@@ -82,7 +84,7 @@ public class AffectedTB3TestLocator extends TB3TestLocator {
         List<String> affectedFilePaths = new ArrayList<>();
 
         for (String path : changedTB3TestLocator.getChangedFilePaths()) {
-            if (!path.toLowerCase().contains("test")) {
+            if (!path.toLowerCase(Locale.ROOT).contains("test")) {
                 affectedFilePaths.add(path);
             }
         }
diff --git a/uitest/src/test/java/com/vaadin/tests/tb3/ChangedTB3TestLocator.java b/uitest/src/test/java/com/vaadin/tests/tb3/ChangedTB3TestLocator.java
index 98a98ffae0..8b3967f087 100644
--- a/uitest/src/test/java/com/vaadin/tests/tb3/ChangedTB3TestLocator.java
+++ b/uitest/src/test/java/com/vaadin/tests/tb3/ChangedTB3TestLocator.java
@@ -19,6 +19,7 @@ import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 
 import org.eclipse.jgit.api.DiffCommand;
 import org.eclipse.jgit.api.Git;
@@ -153,8 +154,8 @@ public class ChangedTB3TestLocator extends TB3TestLocator {
         List<String> changedTestFilePaths = new ArrayList<>();
 
         for (String filePath : getChangedFilePaths()) {
-            if (filePath.toLowerCase().startsWith("uitest")
-                    && filePath.toLowerCase().endsWith(".java")) {
+            if (filePath.toLowerCase(Locale.ROOT).startsWith("uitest")
+                    && filePath.toLowerCase(Locale.ROOT).endsWith(".java")) {
                 changedTestFilePaths.add(filePath);
             }
         }
diff --git a/uitest/src/test/java/com/vaadin/tests/tb3/ParameterizedTB3Runner.java b/uitest/src/test/java/com/vaadin/tests/tb3/ParameterizedTB3Runner.java
index 20107f8058..9cadcece10 100644
--- a/uitest/src/test/java/com/vaadin/tests/tb3/ParameterizedTB3Runner.java
+++ b/uitest/src/test/java/com/vaadin/tests/tb3/ParameterizedTB3Runner.java
@@ -77,7 +77,7 @@ public class ParameterizedTB3Runner extends TB3Runner {
             // getThemes -> setTheme
             String setter = "set" + m.getName().substring("get".length());
             setter = setter.substring(0, setter.length() - 1);
-            // property = property.substring(0, 1).toLowerCase()
+            // property = property.substring(0, 1).toLowerCase(Locale.ROOT)
             // + property.substring(1);
 
             Method setterMethod;
diff --git a/uitest/src/test/java/com/vaadin/tests/tb3/PrivateTB3Configuration.java b/uitest/src/test/java/com/vaadin/tests/tb3/PrivateTB3Configuration.java
index 4a34c355ad..8e55e9140a 100644
--- a/uitest/src/test/java/com/vaadin/tests/tb3/PrivateTB3Configuration.java
+++ b/uitest/src/test/java/com/vaadin/tests/tb3/PrivateTB3Configuration.java
@@ -26,6 +26,7 @@ import java.net.NetworkInterface;
 import java.net.SocketException;
 import java.util.Calendar;
 import java.util.Enumeration;
+import java.util.Locale;
 import java.util.Properties;
 
 import org.openqa.selenium.ie.InternetExplorerDriver;
@@ -131,8 +132,9 @@ public abstract class PrivateTB3Configuration extends ScreenshotTB3Test {
     protected static DesiredCapabilities getRunLocallyCapabilities() {
         VaadinBrowserFactory factory = new VaadinBrowserFactory();
         try {
-            return factory.create(Browser.valueOf(properties
-                    .getProperty(RUN_LOCALLY_PROPERTY).toUpperCase()));
+            return factory.create(
+                    Browser.valueOf(properties.getProperty(RUN_LOCALLY_PROPERTY)
+                            .toUpperCase(Locale.ROOT)));
         } catch (Exception e) {
             System.err.println(e.getMessage());
             System.err.println("Falling back to FireFox");
diff --git a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/GridBasicFeaturesTest.java b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/GridBasicFeaturesTest.java
index 7c4a5962f2..073670f75b 100644
--- a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/GridBasicFeaturesTest.java
+++ b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/GridBasicFeaturesTest.java
@@ -20,6 +20,7 @@ import static org.junit.Assert.assertTrue;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 
 import org.openqa.selenium.By;
 import org.openqa.selenium.JavascriptExecutor;
@@ -146,8 +147,8 @@ public abstract class GridBasicFeaturesTest extends MultiBrowserTest {
 
     protected void assertColumnHeader(String expectedHeaderCaption,
             TestBenchElement testBenchElement) {
-        assertEquals(expectedHeaderCaption.toLowerCase(),
-                testBenchElement.getText().toLowerCase());
+        assertEquals(expectedHeaderCaption.toLowerCase(Locale.ROOT),
+                testBenchElement.getText().toLowerCase(Locale.ROOT));
     }
 
     protected GridCellElement getDefaultColumnHeader(int index) {
@@ -244,7 +245,7 @@ public abstract class GridBasicFeaturesTest extends MultiBrowserTest {
         List<WebElement> elements = sidebar
                 .findElements(By.className("column-hiding-toggle"));
         for (WebElement e : elements) {
-            if ((e.getText().toLowerCase())
+            if ((e.getText().toLowerCase(Locale.ROOT))
                     .startsWith("column " + columnIndex)) {
                 return e;
             }
diff --git a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/GridColumnHidingTest.java b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/GridColumnHidingTest.java
index 6531acb993..c81c024453 100644
--- a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/GridColumnHidingTest.java
+++ b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/GridColumnHidingTest.java
@@ -22,8 +22,8 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
 import java.util.List;
+import java.util.Locale;
 
-import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;
@@ -827,20 +827,17 @@ public class GridColumnHidingTest extends GridBasicClientFeaturesTest {
         selectMenuPath("Component", "Row details", "Toggle details for...",
                 "Row 1");
         assertColumnHeaderOrder(0, 1, 2, 3, 4);
-        assertNotNull("Details not found",
-                getGridElement().getDetails(1));
+        assertNotNull("Details not found", getGridElement().getDetails(1));
 
         toggleHideColumnAPI(0);
 
         assertColumnHeaderOrder(1, 2, 3, 4);
-        assertNotNull("Details not found",
-                getGridElement().getDetails(1));
+        assertNotNull("Details not found", getGridElement().getDetails(1));
 
         toggleHideColumnAPI(0);
 
         assertColumnHeaderOrder(0, 1, 2, 3, 4);
-        assertNotNull("Details not found",
-                getGridElement().getDetails(1));
+        assertNotNull("Details not found", getGridElement().getDetails(1));
     }
 
     @Test
@@ -884,17 +881,13 @@ public class GridColumnHidingTest extends GridBasicClientFeaturesTest {
         toggleHideColumnAPI(1);
 
         getGridElement().scrollToRow(500);
-        assertEquals("(500, 0)",
-                getGridElement().getCell(500, 0).getText());
-        assertEquals("(500, 2)",
-                getGridElement().getCell(500, 1).getText());
+        assertEquals("(500, 0)", getGridElement().getCell(500, 0).getText());
+        assertEquals("(500, 2)", getGridElement().getCell(500, 1).getText());
 
         toggleHideColumnAPI(1);
 
-        assertEquals("(500, 0)",
-                getGridElement().getCell(500, 0).getText());
-        assertEquals("(500, 1)",
-                getGridElement().getCell(500, 1).getText());
+        assertEquals("(500, 0)", getGridElement().getCell(500, 0).getText());
+        assertEquals("(500, 1)", getGridElement().getCell(500, 1).getText());
     }
 
     @Test
@@ -902,26 +895,20 @@ public class GridColumnHidingTest extends GridBasicClientFeaturesTest {
         toggleHidableColumnAPI(0);
         toggleHidableColumnAPI(1);
 
-        assertEquals("(500, 0)",
-                getGridElement().getCell(500, 0).getText());
-        assertEquals("(500, 1)",
-                getGridElement().getCell(500, 1).getText());
+        assertEquals("(500, 0)", getGridElement().getCell(500, 0).getText());
+        assertEquals("(500, 1)", getGridElement().getCell(500, 1).getText());
 
         toggleHideColumnAPI(0);
         toggleHideColumnAPI(1);
 
-        assertEquals("(500, 2)",
-                getGridElement().getCell(500, 0).getText());
-        assertEquals("(500, 3)",
-                getGridElement().getCell(500, 1).getText());
+        assertEquals("(500, 2)", getGridElement().getCell(500, 0).getText());
+        assertEquals("(500, 3)", getGridElement().getCell(500, 1).getText());
 
         toggleHideColumnAPI(0);
         toggleHideColumnAPI(1);
 
-        assertEquals("(500, 0)",
-                getGridElement().getCell(500, 0).getText());
-        assertEquals("(500, 1)",
-                getGridElement().getCell(500, 1).getText());
+        assertEquals("(500, 0)", getGridElement().getCell(500, 0).getText());
+        assertEquals("(500, 1)", getGridElement().getCell(500, 1).getText());
     }
 
     private void loadSpannedCellsFixture() {
@@ -987,7 +974,8 @@ public class GridColumnHidingTest extends GridBasicClientFeaturesTest {
     private void verifyHeaderCellContent(int row, int column, String content) {
         GridCellElement headerCell = getGridElement().getHeaderCell(row,
                 column);
-        assertEquals(content.toLowerCase(), headerCell.getText().toLowerCase());
+        assertEquals(content.toLowerCase(Locale.ROOT),
+                headerCell.getText().toLowerCase(Locale.ROOT));
         assertTrue(headerCell.isDisplayed());
     }
 
diff --git a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridFooterTest.java b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridFooterTest.java
index 906f1fedba..cea86af619 100644
--- a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridFooterTest.java
+++ b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridFooterTest.java
@@ -19,6 +19,8 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;
 
+import java.util.Locale;
+
 import org.junit.Test;
 import org.openqa.selenium.By;
 import org.openqa.selenium.WebElement;
@@ -160,7 +162,8 @@ public class GridFooterTest extends GridStaticSectionTest {
          * Reindeer has a CSS text transformation that changes the casing so
          * that we can't rely on it being what we set
          */
-        assertEquals("footer (0,0)", textCell.getText().toLowerCase());
+        assertEquals("footer (0,0)",
+                textCell.getText().toLowerCase(Locale.ROOT));
 
         GridCellElement widgetCell = getGridElement().getFooterCell(0, 1);
         assertTrue(widgetCell.isElementPresent(By.className("gwt-HTML")));
@@ -193,7 +196,8 @@ public class GridFooterTest extends GridStaticSectionTest {
          * Reindeer has a CSS text transformation that changes the casing so
          * that we can't rely on it being what we set
          */
-        assertEquals("text footer", textCell.getText().toLowerCase());
+        assertEquals("text footer",
+                textCell.getText().toLowerCase(Locale.ROOT));
     }
 
     @Test
@@ -207,11 +211,11 @@ public class GridFooterTest extends GridStaticSectionTest {
         GridCellElement widgetCell = getGridElement().getFooterCell(0, 0);
         WebElement button = widgetCell.findElement(By.className("gwt-Button"));
 
-        assertNotEquals("clicked", button.getText().toLowerCase());
+        assertNotEquals("clicked", button.getText().toLowerCase(Locale.ROOT));
 
         new Actions(getDriver()).moveToElement(button, 5, 5).click().perform();
 
-        assertEquals("clicked", button.getText().toLowerCase());
+        assertEquals("clicked", button.getText().toLowerCase(Locale.ROOT));
     }
 
     private void assertFooterCount(int count) {
diff --git a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridHeaderTest.java b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridHeaderTest.java
index 0f4a10a1af..7ece0ed729 100644
--- a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridHeaderTest.java
+++ b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridHeaderTest.java
@@ -21,6 +21,7 @@ import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;
 
 import java.util.Arrays;
+import java.util.Locale;
 
 import org.junit.Test;
 import org.openqa.selenium.By;
@@ -204,7 +205,8 @@ public class GridHeaderTest extends GridStaticSectionTest {
          * Reindeer has a CSS text transformation that changes the casing so
          * that we can't rely on it being what we set
          */
-        assertEquals("header (0,0)", textCell.getText().toLowerCase());
+        assertEquals("header (0,0)",
+                textCell.getText().toLowerCase(Locale.ROOT));
 
         GridCellElement widgetCell = getGridElement().getHeaderCell(0, 1);
         assertTrue(widgetCell.isElementPresent(By.className("gwt-HTML")));
@@ -235,7 +237,8 @@ public class GridHeaderTest extends GridStaticSectionTest {
          * Reindeer has a CSS text transformation that changes the casing so
          * that we can't rely on it being what we set
          */
-        assertEquals("text header", textCell.getText().toLowerCase());
+        assertEquals("text header",
+                textCell.getText().toLowerCase(Locale.ROOT));
     }
 
     @Test
@@ -249,7 +252,7 @@ public class GridHeaderTest extends GridStaticSectionTest {
 
         new Actions(getDriver()).moveToElement(button, 5, 5).click().perform();
 
-        assertEquals("clicked", button.getText().toLowerCase());
+        assertEquals("clicked", button.getText().toLowerCase(Locale.ROOT));
     }
 
     @Test
@@ -264,11 +267,11 @@ public class GridHeaderTest extends GridStaticSectionTest {
         GridCellElement widgetCell = getGridElement().getHeaderCell(0, 0);
         WebElement button = widgetCell.findElement(By.className("gwt-Button"));
 
-        assertNotEquals("clicked", button.getText().toLowerCase());
+        assertNotEquals("clicked", button.getText().toLowerCase(Locale.ROOT));
 
         new Actions(getDriver()).moveToElement(button, 5, 5).click().perform();
 
-        assertEquals("clicked", button.getText().toLowerCase());
+        assertEquals("clicked", button.getText().toLowerCase(Locale.ROOT));
     }
 
     private void assertHeaderCount(int count) {
diff --git a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridStaticSectionTest.java b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridStaticSectionTest.java
index 835e9d576c..6b9aa813de 100644
--- a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridStaticSectionTest.java
+++ b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/client/GridStaticSectionTest.java
@@ -17,6 +17,8 @@ package com.vaadin.v7.tests.components.grid.basicfeatures.client;
 
 import static org.junit.Assert.assertEquals;
 
+import java.util.Locale;
+
 import org.openqa.selenium.By;
 import org.openqa.selenium.WebElement;
 
@@ -88,8 +90,8 @@ public abstract class GridStaticSectionTest
 
         // IE 8 returns tags as upper case while other browsers do not, make the
         // comparison non-casesensive
-        html = html.toLowerCase();
-        text = text.toLowerCase();
+        html = html.toLowerCase(Locale.ROOT);
+        text = text.toLowerCase(Locale.ROOT);
 
         // IE 8 returns attributes without quotes, make the comparison without
         // quotes
diff --git a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridColumnVisibilityTest.java b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridColumnVisibilityTest.java
index c27afc4fd0..d3f3f74f38 100644
--- a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridColumnVisibilityTest.java
+++ b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridColumnVisibilityTest.java
@@ -21,7 +21,8 @@ import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
-import org.junit.Assert;
+import java.util.Locale;
+
 import org.junit.Before;
 import org.junit.Test;
 
@@ -32,10 +33,10 @@ import com.vaadin.v7.tests.components.grid.basicfeatures.GridBasicFeaturesTest;
 @TestCategory("grid")
 public class GridColumnVisibilityTest extends GridBasicFeaturesTest {
 
-    private static final String[] TOGGLE_LISTENER = { "Component",
-            "State", "ColumnVisibilityChangeListener" };
-    private static final String[] TOGGLE_HIDE_COLUMN_0 = {
-            "Component", "Columns", "Column 0", "Hidden" };
+    private static final String[] TOGGLE_LISTENER = { "Component", "State",
+            "ColumnVisibilityChangeListener" };
+    private static final String[] TOGGLE_HIDE_COLUMN_0 = { "Component",
+            "Columns", "Column 0", "Hidden" };
 
     private static final String COLUMN_0_BECAME_HIDDEN_MSG = "Visibility "
             + "changed: propertyId: Column 0, isHidden: true";
@@ -51,20 +52,20 @@ public class GridColumnVisibilityTest extends GridBasicFeaturesTest {
 
     @Test
     public void columnIsNotShownWhenHidden() {
-        assertEquals("column 0",
-                getGridElement().getHeaderCell(0, 0).getText().toLowerCase());
+        assertEquals("column 0", getGridElement().getHeaderCell(0, 0).getText()
+                .toLowerCase(Locale.ROOT));
 
         selectMenuPath(TOGGLE_HIDE_COLUMN_0);
-        assertEquals("column 1",
-                getGridElement().getHeaderCell(0, 0).getText().toLowerCase());
+        assertEquals("column 1", getGridElement().getHeaderCell(0, 0).getText()
+                .toLowerCase(Locale.ROOT));
     }
 
     @Test
     public void columnIsShownWhenUnhidden() {
         selectMenuPath(TOGGLE_HIDE_COLUMN_0);
         selectMenuPath(TOGGLE_HIDE_COLUMN_0);
-        assertEquals("column 0",
-                getGridElement().getHeaderCell(0, 0).getText().toLowerCase());
+        assertEquals("column 0", getGridElement().getHeaderCell(0, 0).getText()
+                .toLowerCase(Locale.ROOT));
     }
 
     @Test
@@ -170,15 +171,15 @@ public class GridColumnVisibilityTest extends GridBasicFeaturesTest {
     public void testColumnHidingToggleCaption_settingToggleCaption_updatesToggle() {
         toggleColumnHidable(1);
         getSidebarOpenButton().click();
-        assertEquals("column 1",
-                getGridElement().getHeaderCell(0, 1).getText().toLowerCase());
+        assertEquals("column 1", getGridElement().getHeaderCell(0, 1).getText()
+                .toLowerCase(Locale.ROOT));
         assertEquals("Column 1", getColumnHidingToggle(1).getText());
 
         toggleColumnHidingToggleCaptionChange(1);
 
         getSidebarOpenButton().click();
-        assertEquals("column 1",
-                getGridElement().getHeaderCell(0, 1).getText().toLowerCase());
+        assertEquals("column 1", getGridElement().getHeaderCell(0, 1).getText()
+                .toLowerCase(Locale.ROOT));
         assertEquals("Column 1 caption 0", getColumnHidingToggle(1).getText());
 
         toggleColumnHidingToggleCaptionChange(1);
@@ -190,8 +191,8 @@ public class GridColumnVisibilityTest extends GridBasicFeaturesTest {
     public void testColumnHidingToggleCaption_settingWidgetToHeader_toggleCaptionStays() {
         toggleColumnHidable(1);
         getSidebarOpenButton().click();
-        assertEquals("column 1",
-                getGridElement().getHeaderCell(0, 1).getText().toLowerCase());
+        assertEquals("column 1", getGridElement().getHeaderCell(0, 1).getText()
+                .toLowerCase(Locale.ROOT));
         assertEquals("Column 1", getColumnHidingToggle(1).getText());
 
         selectMenuPath("Component", "Columns", "Column 1", "Header Type",
@@ -209,8 +210,8 @@ public class GridColumnVisibilityTest extends GridBasicFeaturesTest {
                 "Change header caption");
 
         getSidebarOpenButton().click();
-        assertEquals("column 1 header 0",
-                getGridElement().getHeaderCell(0, 1).getText().toLowerCase());
+        assertEquals("column 1 header 0", getGridElement().getHeaderCell(0, 1)
+                .getText().toLowerCase(Locale.ROOT));
         assertEquals("Column 1 header 0", getColumnHidingToggle(1).getText());
     }
 
@@ -224,8 +225,8 @@ public class GridColumnVisibilityTest extends GridBasicFeaturesTest {
                 "Change header caption");
 
         getSidebarOpenButton().click();
-        assertEquals("column 1 header 0",
-                getGridElement().getHeaderCell(0, 1).getText().toLowerCase());
+        assertEquals("column 1 header 0", getGridElement().getHeaderCell(0, 1)
+                .getText().toLowerCase(Locale.ROOT));
         assertEquals("Column 1 caption 0", getColumnHidingToggle(1).getText());
     }
 
@@ -322,8 +323,7 @@ public class GridColumnVisibilityTest extends GridBasicFeaturesTest {
         getColumnHidingToggle(3).click();
 
         // Make sure that the new column contains the data it should
-        assertEquals("(999, 3)",
-                getGridElement().getCell(999, 3).getText());
+        assertEquals("(999, 3)", getGridElement().getCell(999, 3).getText());
     }
 
     private void verifyColumnFrozen(int index) {
diff --git a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridStaticSectionComponentTest.java b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridStaticSectionComponentTest.java
index ed0b4a7186..10f9173300 100644
--- a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridStaticSectionComponentTest.java
+++ b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridStaticSectionComponentTest.java
@@ -18,6 +18,8 @@ package com.vaadin.v7.tests.components.grid.basicfeatures.server;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
+import java.util.Locale;
+
 import org.junit.Test;
 
 import com.vaadin.testbench.elements.ButtonElement;
@@ -64,8 +66,8 @@ public class GridStaticSectionComponentTest extends GridBasicFeaturesTest {
         assertTrue("No notifications should've been shown",
                 !$(NotificationElement.class).exists());
         assertEquals("Header should've been reverted back to text header",
-                "text header",
-                getGridElement().getHeaderCell(0, 1).getText().toLowerCase());
+                "text header", getGridElement().getHeaderCell(0, 1).getText()
+                        .toLowerCase(Locale.ROOT));
     }
 
 }
diff --git a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridStructureTest.java b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridStructureTest.java
index 53a229a4c0..1d139b67a9 100644
--- a/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridStructureTest.java
+++ b/uitest/src/test/java/com/vaadin/v7/tests/components/grid/basicfeatures/server/GridStructureTest.java
@@ -24,6 +24,7 @@ import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.util.List;
+import java.util.Locale;
 
 import org.junit.Test;
 import org.openqa.selenium.NoSuchElementException;
@@ -58,11 +59,11 @@ public class GridStructureTest extends GridBasicFeaturesTest {
         setDebug(true);
         openTestURL();
 
-        assertEquals("column 0",
-                getGridElement().getHeaderCell(0, 0).getText().toLowerCase());
+        assertEquals("column 0", getGridElement().getHeaderCell(0, 0).getText()
+                .toLowerCase(Locale.ROOT));
         selectMenuPath("Component", "Columns", "Column 0", "Add / Remove");
-        assertEquals("column 1",
-                getGridElement().getHeaderCell(0, 0).getText().toLowerCase());
+        assertEquals("column 1", getGridElement().getHeaderCell(0, 0).getText()
+                .toLowerCase(Locale.ROOT));
         selectMenuPath("Component", "Columns", "Column 0", "Add / Remove");
 
         // Column 0 is now the last column in Grid.
@@ -76,14 +77,16 @@ public class GridStructureTest extends GridBasicFeaturesTest {
 
         // Column 0 should be visible
         List<TestBenchElement> cells = getGridHeaderRowCells();
-        assertEquals("column 0", cells.get(0).getText().toLowerCase());
+        assertEquals("column 0",
+                cells.get(0).getText().toLowerCase(Locale.ROOT));
 
         // Hide column 0
         selectMenuPath("Component", "Columns", "Column 0", "Add / Remove");
 
         // Column 1 should now be the first cell
         cells = getGridHeaderRowCells();
-        assertEquals("column 1", cells.get(0).getText().toLowerCase());
+        assertEquals("column 1",
+                cells.get(0).getText().toLowerCase(Locale.ROOT));
     }
 
     @Test