diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/MessageOfTheDayBar.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/MessageOfTheDayBar.java
index b6ea6367c2..054cdb3219 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/MessageOfTheDayBar.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/MessageOfTheDayBar.java
@@ -67,7 +67,7 @@ class MessageOfTheDayBar extends Composite {
   }
 
   @UiHandler("dismiss")
-  void onDismiss(ClickEvent e) {
+  void onDismiss(@SuppressWarnings("unused") ClickEvent e) {
     removeFromParent();
 
     for (HostPageData.Message m : motd) {
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AccessSectionEditor.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AccessSectionEditor.java
index 3a0d2f7b4a..e25e2a8bcf 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AccessSectionEditor.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AccessSectionEditor.java
@@ -109,17 +109,17 @@ public class AccessSectionEditor extends Composite implements
   }
 
   @UiHandler("deleteSection")
-  void onDeleteHover(MouseOverEvent event) {
+  void onDeleteHover(@SuppressWarnings("unused") MouseOverEvent event) {
     normal.addClassName(AdminResources.I.css().deleteSectionHover());
   }
 
   @UiHandler("deleteSection")
-  void onDeleteNonHover(MouseOutEvent event) {
+  void onDeleteNonHover(@SuppressWarnings("unused") MouseOutEvent event) {
     normal.removeClassName(AdminResources.I.css().deleteSectionHover());
   }
 
   @UiHandler("deleteSection")
-  void onDeleteSection(ClickEvent event) {
+  void onDeleteSection(@SuppressWarnings("unused") ClickEvent event) {
     isDeleted = true;
 
     if (name.isVisible()
@@ -139,7 +139,7 @@ public class AccessSectionEditor extends Composite implements
   }
 
   @UiHandler("undoDelete")
-  void onUndoDelete(ClickEvent event) {
+  void onUndoDelete(@SuppressWarnings("unused") ClickEvent event) {
     isDeleted = false;
     deleted.getStyle().setDisplay(Display.NONE);
     normal.getStyle().setDisplay(Display.BLOCK);
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/PermissionEditor.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/PermissionEditor.java
index b3d856458f..b9baccc76c 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/PermissionEditor.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/PermissionEditor.java
@@ -145,31 +145,31 @@ public class PermissionEditor extends Composite implements Editor<Permission>,
   }
 
   @UiHandler("deletePermission")
-  void onDeleteHover(MouseOverEvent event) {
+  void onDeleteHover(@SuppressWarnings("unused") MouseOverEvent event) {
     addStyleName(AdminResources.I.css().deleteSectionHover());
   }
 
   @UiHandler("deletePermission")
-  void onDeleteNonHover(MouseOutEvent event) {
+  void onDeleteNonHover(@SuppressWarnings("unused") MouseOutEvent event) {
     removeStyleName(AdminResources.I.css().deleteSectionHover());
   }
 
   @UiHandler("deletePermission")
-  void onDeletePermission(ClickEvent event) {
+  void onDeletePermission(@SuppressWarnings("unused") ClickEvent event) {
     isDeleted = true;
     normal.getStyle().setDisplay(Display.NONE);
     deleted.getStyle().setDisplay(Display.BLOCK);
   }
 
   @UiHandler("undoDelete")
-  void onUndoDelete(ClickEvent event) {
+  void onUndoDelete(@SuppressWarnings("unused") ClickEvent event) {
     isDeleted = false;
     deleted.getStyle().setDisplay(Display.NONE);
     normal.getStyle().setDisplay(Display.BLOCK);
   }
 
   @UiHandler("beginAddRule")
-  void onBeginAddRule(ClickEvent event) {
+  void onBeginAddRule(@SuppressWarnings("unused") ClickEvent event) {
     beginAddRule();
   }
 
@@ -186,7 +186,7 @@ public class PermissionEditor extends Composite implements Editor<Permission>,
   }
 
   @UiHandler("addRule")
-  void onAddGroupByClick(ClickEvent event) {
+  void onAddGroupByClick(@SuppressWarnings("unused") ClickEvent event) {
     GroupReference ref = groupToAdd.getValue();
     if (ref != null) {
       addGroup(ref);
@@ -204,12 +204,13 @@ public class PermissionEditor extends Composite implements Editor<Permission>,
   }
 
   @UiHandler("groupToAdd")
-  void onAbortAddGroup(CloseEvent<GroupReferenceBox> event) {
+  void onAbortAddGroup(
+      @SuppressWarnings("unused") CloseEvent<GroupReferenceBox> event) {
     hideAddGroup();
   }
 
   @UiHandler("hideAddGroup")
-  void hideAddGroup(ClickEvent event) {
+  void hideAddGroup(@SuppressWarnings("unused") ClickEvent event) {
     hideAddGroup();
   }
 
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/PermissionRuleEditor.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/PermissionRuleEditor.java
index 9e719ead68..163702c07e 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/PermissionRuleEditor.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/PermissionRuleEditor.java
@@ -176,14 +176,14 @@ public class PermissionRuleEditor extends Composite implements
   }
 
   @UiHandler("deleteRule")
-  void onDeleteRule(ClickEvent event) {
+  void onDeleteRule(@SuppressWarnings("unused") ClickEvent event) {
     isDeleted = true;
     normal.getStyle().setDisplay(Display.NONE);
     deleted.getStyle().setDisplay(Display.BLOCK);
   }
 
   @UiHandler("undoDelete")
-  void onUndoDelete(ClickEvent event) {
+  void onUndoDelete(@SuppressWarnings("unused") ClickEvent event) {
     isDeleted = false;
     deleted.getStyle().setDisplay(Display.NONE);
     normal.getStyle().setDisplay(Display.BLOCK);
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectAccessEditor.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectAccessEditor.java
index 8981e8282b..55bc655237 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectAccessEditor.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectAccessEditor.java
@@ -84,7 +84,7 @@ public class ProjectAccessEditor extends Composite implements
   }
 
   @UiHandler("addSection")
-  void onAddSection(ClickEvent event) {
+  void onAddSection(@SuppressWarnings("unused") ClickEvent event) {
     int index = local.getList().size();
     local.getList().add(new AccessSection("refs/heads/*"));
 
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectAccessScreen.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectAccessScreen.java
index 9c6cc1d1a7..b86d0a8397 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectAccessScreen.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectAccessScreen.java
@@ -159,7 +159,7 @@ public class ProjectAccessScreen extends ProjectScreen {
   }
 
   @UiHandler("edit")
-  void onEdit(ClickEvent event) {
+  void onEdit(@SuppressWarnings("unused") ClickEvent event) {
     resetEditors();
 
     edit.setEnabled(false);
@@ -184,12 +184,12 @@ public class ProjectAccessScreen extends ProjectScreen {
   }
 
   @UiHandler(value={"cancel1", "cancel2"})
-  void onCancel(ClickEvent event) {
+  void onCancel(@SuppressWarnings("unused") ClickEvent event) {
     Gerrit.display(PageLinks.toProjectAcceess(getProjectKey()));
   }
 
   @UiHandler("commit")
-  void onCommit(ClickEvent event) {
+  void onCommit(@SuppressWarnings("unused") ClickEvent event) {
     final ProjectAccess access = driver.flush();
 
     if (driver.hasErrors()) {
@@ -267,7 +267,7 @@ public class ProjectAccessScreen extends ProjectScreen {
   }
 
   @UiHandler("review")
-  void onReview(ClickEvent event) {
+  void onReview(@SuppressWarnings("unused") ClickEvent event) {
     final ProjectAccess access = driver.flush();
 
     if (driver.hasErrors()) {
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ActionMessageBox.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ActionMessageBox.java
index 45f122c593..c560f6d905 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ActionMessageBox.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ActionMessageBox.java
@@ -98,7 +98,7 @@ abstract class ActionMessageBox extends Composite {
   }
 
   @UiHandler("send")
-  void onSend(ClickEvent e) {
+  void onSend(@SuppressWarnings("unused") ClickEvent e) {
     send(message.getValue().trim());
   }
 }
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Actions.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Actions.java
index 5e7105c1eb..b5090ca53d 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Actions.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Actions.java
@@ -185,7 +185,7 @@ class Actions extends Composite {
   }
 
   @UiHandler("followUp")
-  void onFollowUp(ClickEvent e) {
+  void onFollowUp(@SuppressWarnings("unused") ClickEvent e) {
     if (followUpAction == null) {
       followUpAction = new FollowUpAction(followUp, project,
           branch, key);
@@ -194,7 +194,7 @@ class Actions extends Composite {
   }
 
   @UiHandler("abandon")
-  void onAbandon(ClickEvent e) {
+  void onAbandon(@SuppressWarnings("unused") ClickEvent e) {
     if (abandonAction == null) {
       abandonAction = new AbandonAction(abandon, changeId);
     }
@@ -202,37 +202,37 @@ class Actions extends Composite {
   }
 
   @UiHandler("publish")
-  void onPublish(ClickEvent e) {
+  void onPublish(@SuppressWarnings("unused") ClickEvent e) {
     DraftActions.publish(changeId, revision);
   }
 
   @UiHandler("deleteEdit")
-  void onDeleteEdit(ClickEvent e) {
+  void onDeleteEdit(@SuppressWarnings("unused") ClickEvent e) {
     EditActions.deleteEdit(changeId);
   }
 
   @UiHandler("publishEdit")
-  void onPublishEdit(ClickEvent e) {
+  void onPublishEdit(@SuppressWarnings("unused") ClickEvent e) {
     EditActions.publishEdit(changeId);
   }
 
   @UiHandler("rebaseEdit")
-  void onRebaseEdit(ClickEvent e) {
+  void onRebaseEdit(@SuppressWarnings("unused") ClickEvent e) {
     EditActions.rebaseEdit(changeId);
   }
 
   @UiHandler("deleteRevision")
-  void onDeleteRevision(ClickEvent e) {
+  void onDeleteRevision(@SuppressWarnings("unused") ClickEvent e) {
     DraftActions.delete(changeId, revision);
   }
 
   @UiHandler("deleteChange")
-  void onDeleteChange(ClickEvent e) {
+  void onDeleteChange(@SuppressWarnings("unused") ClickEvent e) {
     DraftActions.delete(changeId);
   }
 
   @UiHandler("restore")
-  void onRestore(ClickEvent e) {
+  void onRestore(@SuppressWarnings("unused") ClickEvent e) {
     if (restoreAction == null) {
       restoreAction = new RestoreAction(restore, changeId);
     }
@@ -240,22 +240,22 @@ class Actions extends Composite {
   }
 
   @UiHandler("rebase")
-  void onRebase(ClickEvent e) {
+  void onRebase(@SuppressWarnings("unused") ClickEvent e) {
     RebaseAction.call(changeId, revision);
   }
 
   @UiHandler("submit")
-  void onSubmit(ClickEvent e) {
+  void onSubmit(@SuppressWarnings("unused") ClickEvent e) {
     SubmitAction.call(changeInfo, changeInfo.revision(revision));
   }
 
   @UiHandler("cherrypick")
-  void onCherryPick(ClickEvent e) {
+  void onCherryPick(@SuppressWarnings("unused") ClickEvent e) {
     CherryPickAction.call(cherrypick, changeInfo, revision, project, message);
   }
 
   @UiHandler("revert")
-  void onRevert(ClickEvent e) {
+  void onRevert(@SuppressWarnings("unused") ClickEvent e) {
     RevertAction.call(revert, changeId, revision, subject);
   }
 
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen2.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen2.java
index 8c79f898b7..5c75c0b7cb 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen2.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen2.java
@@ -538,22 +538,22 @@ public class ChangeScreen2 extends Screen {
   }
 
   @UiHandler("includedIn")
-  void onIncludedIn(ClickEvent e) {
+  void onIncludedIn(@SuppressWarnings("unused") ClickEvent e) {
     includedInAction.show();
   }
 
   @UiHandler("download")
-  void onDownload(ClickEvent e) {
+  void onDownload(@SuppressWarnings("unused") ClickEvent e) {
     downloadAction.show();
   }
 
   @UiHandler("patchSets")
-  void onPatchSets(ClickEvent e) {
+  void onPatchSets(@SuppressWarnings("unused") ClickEvent e) {
     patchSetsAction.show();
   }
 
   @UiHandler("reply")
-  void onReply(ClickEvent e) {
+  void onReply(@SuppressWarnings("unused") ClickEvent e) {
     onReply();
   }
 
@@ -572,17 +572,17 @@ public class ChangeScreen2 extends Screen {
   }
 
   @UiHandler("editMessage")
-  void onEditMessage(ClickEvent e) {
+  void onEditMessage(@SuppressWarnings("unused") ClickEvent e) {
     editMessageAction.onEdit();
   }
 
   @UiHandler("openAll")
-  void onOpenAll(ClickEvent e) {
+  void onOpenAll(@SuppressWarnings("unused") ClickEvent e) {
     files.openAll();
   }
 
   @UiHandler("editMode")
-  void onEditMode(ClickEvent e) {
+  void onEditMode(@SuppressWarnings("unused") ClickEvent e) {
     fileTableMode = FileTable.Mode.EDIT;
     refreshFileTable();
     editMode.setVisible(false);
@@ -591,7 +591,7 @@ public class ChangeScreen2 extends Screen {
   }
 
   @UiHandler("reviewMode")
-  void onReviewMode(ClickEvent e) {
+  void onReviewMode(@SuppressWarnings("unused") ClickEvent e) {
     fileTableMode = FileTable.Mode.REVIEW;
     refreshFileTable();
     editMode.setVisible(true);
@@ -600,7 +600,7 @@ public class ChangeScreen2 extends Screen {
   }
 
   @UiHandler("addFile")
-  void onAddFile(ClickEvent e) {
+  void onAddFile(@SuppressWarnings("unused") ClickEvent e) {
     editFileAction.onEdit();
   }
 
@@ -613,7 +613,7 @@ public class ChangeScreen2 extends Screen {
   }
 
   @UiHandler("expandAll")
-  void onExpandAll(ClickEvent e) {
+  void onExpandAll(@SuppressWarnings("unused") ClickEvent e) {
     int n = history.getWidgetCount();
     for (int i = 0; i < n; i++) {
       ((Message) history.getWidget(i)).setOpen(true);
@@ -623,7 +623,7 @@ public class ChangeScreen2 extends Screen {
   }
 
   @UiHandler("collapseAll")
-  void onCollapseAll(ClickEvent e) {
+  void onCollapseAll(@SuppressWarnings("unused") ClickEvent e) {
     int n = history.getWidgetCount();
     for (int i = 0; i < n; i++) {
       ((Message) history.getWidget(i)).setOpen(false);
@@ -633,7 +633,7 @@ public class ChangeScreen2 extends Screen {
   }
 
   @UiHandler("diffBase")
-  void onChangeRevision(ChangeEvent e) {
+  void onChangeRevision(@SuppressWarnings("unused") ChangeEvent e) {
     int idx = diffBase.getSelectedIndex();
     if (0 <= idx) {
       String n = diffBase.getValue(idx);
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/CommitBox.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/CommitBox.java
index 1705675198..5bb4639b6c 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/CommitBox.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/CommitBox.java
@@ -87,7 +87,7 @@ class CommitBox extends Composite {
   }
 
   @UiHandler("more")
-  void onMore(ClickEvent e) {
+  void onMore(@SuppressWarnings("unused") ClickEvent e) {
     if (expanded) {
       removeStyleName(style.expanded());
       addStyleName(style.collapsed());
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/EditFileBox.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/EditFileBox.java
index cd5d5f16ee..9bf961e9a3 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/EditFileBox.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/EditFileBox.java
@@ -80,7 +80,7 @@ class EditFileBox extends Composite {
   }
 
   @UiHandler("save")
-  void onSave(ClickEvent e) {
+  void onSave(@SuppressWarnings("unused") ClickEvent e) {
     ChangeFileApi.putContent(id, file.getText(), content.getText(),
         new AsyncCallback<VoidResult>() {
           @Override
@@ -96,7 +96,7 @@ class EditFileBox extends Composite {
   }
 
   @UiHandler("cancel")
-  void onCancel(ClickEvent e) {
+  void onCancel(@SuppressWarnings("unused") ClickEvent e) {
     hide();
   }
 
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/EditMessageBox.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/EditMessageBox.java
index 309908f440..5bb81484e6 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/EditMessageBox.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/EditMessageBox.java
@@ -80,7 +80,7 @@ class EditMessageBox extends Composite {
   }
 
   @UiHandler("save")
-  void onSave(ClickEvent e) {
+  void onSave(@SuppressWarnings("unused") ClickEvent e) {
     save.setEnabled(false);
     ChangeApi.message(changeId.get(), revision, message.getText().trim(),
         new GerritCallback<JavaScriptObject>() {
@@ -93,7 +93,7 @@ class EditMessageBox extends Composite {
   }
 
   @UiHandler("cancel")
-  void onCancel(ClickEvent e) {
+  void onCancel(@SuppressWarnings("unused") ClickEvent e) {
     message.setText("");
     hide();
   }
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Hashtags.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Hashtags.java
index 4d06674ffd..1e6192a747 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Hashtags.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Hashtags.java
@@ -128,7 +128,7 @@ public class Hashtags extends Composite {
   }
 
   @UiHandler("openForm")
-  void onOpenForm(ClickEvent e) {
+  void onOpenForm(@SuppressWarnings("unused") ClickEvent e) {
     onOpenForm();
   }
 
@@ -182,14 +182,14 @@ public class Hashtags extends Composite {
   }
 
   @UiHandler("cancel")
-  void onCancel(ClickEvent e) {
+  void onCancel(@SuppressWarnings("unused") ClickEvent e) {
     openForm.setVisible(true);
     UIObject.setVisible(form, false);
     hashtagTextBox.setFocus(false);
   }
 
   @UiHandler("add")
-  void onAdd(ClickEvent e) {
+  void onAdd(@SuppressWarnings("unused") ClickEvent e) {
     String hashtag = hashtagTextBox.getText();
     if (!hashtag.isEmpty()) {
       addHashtag(hashtag);
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/NewChangeScreenBar.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/NewChangeScreenBar.java
index fa65514144..165ea68f82 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/NewChangeScreenBar.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/NewChangeScreenBar.java
@@ -65,13 +65,13 @@ class NewChangeScreenBar extends Composite {
   }
 
   @UiHandler("keepOld")
-  void onKeepOld(ClickEvent e) {
+  void onKeepOld(@SuppressWarnings("unused") ClickEvent e) {
     save(ChangeScreen.OLD_UI);
     Gerrit.display(PageLinks.toChange(id));
   }
 
   @UiHandler("keepNew")
-  void onKeepNew(ClickEvent e) {
+  void onKeepNew(@SuppressWarnings("unused") ClickEvent e) {
     save(ChangeScreen.CHANGE_SCREEN2);
   }
 
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ReplyBox.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ReplyBox.java
index ddd650e8fb..5eb936c7ba 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ReplyBox.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ReplyBox.java
@@ -188,7 +188,7 @@ class ReplyBox extends Composite {
   }
 
   @UiHandler("post")
-  void onPost(ClickEvent e) {
+  void onPost(@SuppressWarnings("unused") ClickEvent e) {
     postReview();
   }
 
@@ -214,7 +214,7 @@ class ReplyBox extends Composite {
   }
 
   @UiHandler("cancel")
-  void onCancel(ClickEvent e) {
+  void onCancel(@SuppressWarnings("unused") ClickEvent e) {
     message.setText("");
     hide();
   }
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Reviewers.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Reviewers.java
index 5339c07c91..ae4834cecf 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Reviewers.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Reviewers.java
@@ -127,7 +127,7 @@ public class Reviewers extends Composite {
   }
 
   @UiHandler("openForm")
-  void onOpenForm(ClickEvent e) {
+  void onOpenForm(@SuppressWarnings("unused") ClickEvent e) {
     onOpenForm();
   }
 
@@ -139,7 +139,7 @@ public class Reviewers extends Composite {
   }
 
   @UiHandler("add")
-  void onAdd(ClickEvent e) {
+  void onAdd(@SuppressWarnings("unused") ClickEvent e) {
     String reviewer = suggestBox.getText();
     if (!reviewer.isEmpty()) {
       addReviewer(reviewer, false);
@@ -147,13 +147,13 @@ public class Reviewers extends Composite {
   }
 
   @UiHandler("addme")
-  void onAddMe(ClickEvent e) {
+  void onAddMe(@SuppressWarnings("unused") ClickEvent e) {
     String accountId = String.valueOf(Gerrit.getUserAccountInfo()._account_id());
     addReviewer(accountId, false);
   }
 
   @UiHandler("cancel")
-  void onCancel(ClickEvent e) {
+  void onCancel(@SuppressWarnings("unused") ClickEvent e) {
     openForm.setVisible(true);
     UIObject.setVisible(form, false);
     suggestBox.setFocus(false);
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Topic.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Topic.java
index 512203a22b..21016e4c84 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Topic.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/Topic.java
@@ -105,7 +105,7 @@ class Topic extends Composite {
   }
 
   @UiHandler("cancel")
-  void onCancel(ClickEvent e) {
+  void onCancel(@SuppressWarnings("unused") ClickEvent e) {
     input.setFocus(false);
     UIObject.setVisible(form, false);
   }
@@ -121,7 +121,7 @@ class Topic extends Composite {
   }
 
   @UiHandler("save")
-  void onSave(ClickEvent e) {
+  void onSave(@SuppressWarnings("unused") ClickEvent e) {
     ChangeApi.topic(
         psId.getParentKey().get(),
         input.getValue().trim(),
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/UpdateAvailableBar.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/UpdateAvailableBar.java
index 2b6f418e31..cdbc6938c4 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/UpdateAvailableBar.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/change/UpdateAvailableBar.java
@@ -61,12 +61,12 @@ abstract class UpdateAvailableBar extends Composite {
   }
 
   @UiHandler("show")
-  void onShow(ClickEvent e) {
+  void onShow(@SuppressWarnings("unused") ClickEvent e) {
     onShow();
   }
 
   @UiHandler("ignore")
-  void onIgnore(ClickEvent e) {
+  void onIgnore(@SuppressWarnings("unused") ClickEvent e) {
     onIgnore(updated);
     removeFromParent();
   }
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/DraftBox.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/DraftBox.java
index 6b0d69a7b1..2793d012cc 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/DraftBox.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/DraftBox.java
@@ -253,7 +253,7 @@ class DraftBox extends CommentBox {
   }
 
   @UiHandler("message")
-  void onMessageDoubleClick(DoubleClickEvent e) {
+  void onMessageDoubleClick(@SuppressWarnings("unused") DoubleClickEvent e) {
     setEdit(true);
   }
 
@@ -389,7 +389,7 @@ class DraftBox extends CommentBox {
   }
 
   @UiHandler("editArea")
-  void onBlur(BlurEvent e) {
+  void onBlur(@SuppressWarnings("unused") BlurEvent e) {
     resizeTimer.cancel();
   }
 
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/Header.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/Header.java
index 8c10c9093e..3772b01d5d 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/Header.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/Header.java
@@ -242,7 +242,7 @@ class Header extends Composite {
   }
 
   @UiHandler("preferences")
-  void onPreferences(ClickEvent e) {
+  void onPreferences(@SuppressWarnings("unused") ClickEvent e) {
     prefsAction.show();
   }
 
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PatchSetSelectBox2.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PatchSetSelectBox2.java
index 2650a1e918..4e336e1921 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PatchSetSelectBox2.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PatchSetSelectBox2.java
@@ -193,7 +193,7 @@ class PatchSetSelectBox2 extends Composite {
   }
 
   @UiHandler("icon")
-  void onIconClick(ClickEvent e) {
+  void onIconClick(@SuppressWarnings("unused") ClickEvent e) {
     parent.getCmFromSide(side).scrollToY(0);
     parent.getCommentManager().insertNewDraft(side, 0);
   }
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.java
index 0978d1303a..9ea5c8d679 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/PreferencesBox.java
@@ -194,7 +194,7 @@ class PreferencesBox extends Composite {
   }
 
   @UiHandler("ignoreWhitespace")
-  void onIgnoreWhitespace(ChangeEvent e) {
+  void onIgnoreWhitespace(@SuppressWarnings("unused") ChangeEvent e) {
     prefs.ignoreWhitespace(Whitespace.valueOf(
         ignoreWhitespace.getValue(ignoreWhitespace.getSelectedIndex())));
     view.reloadDiffInfo();
@@ -347,7 +347,7 @@ class PreferencesBox extends Composite {
   }
 
   @UiHandler("mode")
-  void onMode(ChangeEvent e) {
+  void onMode(@SuppressWarnings("unused") ChangeEvent e) {
     final String m = mode.getValue(mode.getSelectedIndex());
     prefs.syntaxHighlighting(true);
     syntaxHighlighting.setValue(true, false);
@@ -389,7 +389,7 @@ class PreferencesBox extends Composite {
   }
 
   @UiHandler("theme")
-  void onTheme(ChangeEvent e) {
+  void onTheme(@SuppressWarnings("unused") ChangeEvent e) {
     prefs.theme(Theme.valueOf(theme.getValue(theme.getSelectedIndex())));
     view.setThemeStyles(prefs.theme().isDark());
     view.operation(new Runnable() {
@@ -403,12 +403,12 @@ class PreferencesBox extends Composite {
   }
 
   @UiHandler("apply")
-  void onApply(ClickEvent e) {
+  void onApply(@SuppressWarnings("unused") ClickEvent e) {
     close();
   }
 
   @UiHandler("save")
-  void onSave(ClickEvent e) {
+  void onSave(@SuppressWarnings("unused") ClickEvent e) {
     AccountApi.putDiffPreferences(prefs, new GerritCallback<DiffPreferences>() {
       @Override
       public void onSuccess(DiffPreferences result) {
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SkipBar.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SkipBar.java
index 4efaf54df5..c69bc075be 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SkipBar.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/diff/SkipBar.java
@@ -174,7 +174,7 @@ class SkipBar extends Composite {
   }
 
   @UiHandler("skipNum")
-  void onExpandAll(ClickEvent e) {
+  void onExpandAll(@SuppressWarnings("unused") ClickEvent e) {
     expandAll();
     updateSelection();
     otherBar.updateSelection();
@@ -189,13 +189,13 @@ class SkipBar extends Composite {
   }
 
   @UiHandler("upArrow")
-  void onExpandBefore(ClickEvent e) {
+  void onExpandBefore(@SuppressWarnings("unused") ClickEvent e) {
     expandBefore(NUM_ROWS_TO_EXPAND);
     cm.focus();
   }
 
   @UiHandler("downArrow")
-  void onExpandAfter(ClickEvent e) {
+  void onExpandAfter(@SuppressWarnings("unused") ClickEvent e) {
     expandAfter();
     otherBar.expandAfter();
     manager.getOverviewBar().refresh();
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/patches/PatchScriptSettingsPanel.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/patches/PatchScriptSettingsPanel.java
index 2fe2d45880..264e043afc 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/patches/PatchScriptSettingsPanel.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/patches/PatchScriptSettingsPanel.java
@@ -230,12 +230,12 @@ public class PatchScriptSettingsPanel extends Composite {
   }
 
   @UiHandler("update")
-  void onUpdate(ClickEvent event) {
+  void onUpdate(@SuppressWarnings("unused") ClickEvent event) {
     update();
   }
 
   @UiHandler("save")
-  void onSave(ClickEvent event) {
+  void onSave(@SuppressWarnings("unused") ClickEvent event) {
     save();
   }
 
diff --git a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Daemon.java b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Daemon.java
index cc0029414f..150b44ccc3 100644
--- a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Daemon.java
+++ b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/Daemon.java
@@ -107,7 +107,7 @@ public class Daemon extends SiteProgram {
   private Boolean httpd;
 
   @Option(name = "--disable-httpd", usage = "Disable the internal HTTP daemon")
-  void setDisableHttpd(final boolean arg) {
+  void setDisableHttpd(@SuppressWarnings("unused") boolean arg) {
     httpd = false;
   }
 
@@ -115,7 +115,7 @@ public class Daemon extends SiteProgram {
   private boolean sshd = true;
 
   @Option(name = "--disable-sshd", usage = "Disable the internal SSH daemon")
-  void setDisableSshd(final boolean arg) {
+  void setDisableSshd(@SuppressWarnings("unused")  boolean arg) {
     sshd = false;
   }
 
diff --git a/gerrit-server/src/main/java/com/google/gerrit/rules/StoredValue.java b/gerrit-server/src/main/java/com/google/gerrit/rules/StoredValue.java
index 132360b890..d454e409d8 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/rules/StoredValue.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/rules/StoredValue.java
@@ -84,7 +84,12 @@ public class StoredValue<T> {
     env.set(this, obj);
   }
 
-  /** Creates a value to store, returns null by default. */
+  /**
+   * Creates a value to store, returns null by default.
+   *
+   * @param engine Prolog engine.
+   * @return new value.
+   */
   protected T createValue(Prolog engine) {
     return null;
   }
diff --git a/gerrit-server/src/test/java/com/google/gerrit/rules/PrologTestCase.java b/gerrit-server/src/test/java/com/google/gerrit/rules/PrologTestCase.java
index 1bc78f80af..0f00afbe5e 100644
--- a/gerrit-server/src/test/java/com/google/gerrit/rules/PrologTestCase.java
+++ b/gerrit-server/src/test/java/com/google/gerrit/rules/PrologTestCase.java
@@ -82,6 +82,11 @@ public abstract class PrologTestCase {
     machine = PrologMachineCopy.save(env);
   }
 
+  /**
+   * Set up the Prolog environment.
+   *
+   * @param env Prolog environment.
+   */
   protected void setUpEnvironment(PrologEnvironment env) {
   }
 
diff --git a/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/CreateProjectCommand.java b/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/CreateProjectCommand.java
index e8536a1b96..219dab56a1 100644
--- a/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/CreateProjectCommand.java
+++ b/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/CreateProjectCommand.java
@@ -90,27 +90,27 @@ final class CreateProjectCommand extends SshCommand {
   private InheritableBoolean createNewChangeForAllNotInTarget = InheritableBoolean.INHERIT;
 
   @Option(name = "--use-contributor-agreements", aliases = {"--ca"}, usage = "if contributor agreement is required")
-  void setUseContributorArgreements(boolean on) {
+  void setUseContributorArgreements(@SuppressWarnings("unused") boolean on) {
     contributorAgreements = InheritableBoolean.TRUE;
   }
 
   @Option(name = "--use-signed-off-by", aliases = {"--so"}, usage = "if signed-off-by is required")
-  void setUseSignedOffBy(boolean on) {
+  void setUseSignedOffBy(@SuppressWarnings("unused") boolean on) {
     signedOffBy = InheritableBoolean.TRUE;
   }
 
   @Option(name = "--use-content-merge", usage = "allow automatic conflict resolving within files")
-  void setUseContentMerge(boolean on) {
+  void setUseContentMerge(@SuppressWarnings("unused") boolean on) {
     contentMerge = InheritableBoolean.TRUE;
   }
 
   @Option(name = "--require-change-id", aliases = {"--id"}, usage = "if change-id is required")
-  void setRequireChangeId(boolean on) {
+  void setRequireChangeId(@SuppressWarnings("unused") boolean on) {
     requireChangeID = InheritableBoolean.TRUE;
   }
 
   @Option(name = "--create-new-change-for-all-not-in-target", aliases = {"--ncfa"}, usage = "if a new change will be created for every commit not in target branch")
-  void setNewChangeForAllNotInTarget(boolean on) {
+  void setNewChangeForAllNotInTarget(@SuppressWarnings("unused") boolean on) {
     createNewChangeForAllNotInTarget = InheritableBoolean.TRUE;
   }
 
diff --git a/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/PluginInstallCommand.java b/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/PluginInstallCommand.java
index 49120f7f4b..799686d656 100644
--- a/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/PluginInstallCommand.java
+++ b/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/PluginInstallCommand.java
@@ -44,7 +44,7 @@ final class PluginInstallCommand extends SshCommand {
   private String name;
 
   @Option(name = "-")
-  void useInput(boolean on) {
+  void useInput(@SuppressWarnings("unused") boolean on) {
     source = "-";
   }
 
diff --git a/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/SetProjectCommand.java b/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/SetProjectCommand.java
index cc72e968a9..0d7cf4dcdd 100644
--- a/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/SetProjectCommand.java
+++ b/gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/SetProjectCommand.java
@@ -66,42 +66,42 @@ final class SetProjectCommand extends SshCommand {
   private InheritableBoolean requireChangeID;
 
   @Option(name = "--use-contributor-agreements", aliases = {"--ca"}, usage = "if contributor agreement is required")
-  void setUseContributorArgreements(boolean on) {
+  void setUseContributorArgreements(@SuppressWarnings("unused") boolean on) {
     contributorAgreements = InheritableBoolean.TRUE;
   }
 
   @Option(name = "--no-contributor-agreements", aliases = {"--nca"}, usage = "if contributor agreement is not required")
-  void setNoContributorArgreements(boolean on) {
+  void setNoContributorArgreements(@SuppressWarnings("unused") boolean on) {
     contributorAgreements = InheritableBoolean.FALSE;
   }
 
   @Option(name = "--use-signed-off-by", aliases = {"--so"}, usage = "if signed-off-by is required")
-  void setUseSignedOffBy(boolean on) {
+  void setUseSignedOffBy(@SuppressWarnings("unused") boolean on) {
     signedOffBy = InheritableBoolean.TRUE;
   }
 
   @Option(name = "--no-signed-off-by", aliases = {"--nso"}, usage = "if signed-off-by is not required")
-  void setNoSignedOffBy(boolean on) {
+  void setNoSignedOffBy(@SuppressWarnings("unused") boolean on) {
     signedOffBy = InheritableBoolean.FALSE;
   }
 
   @Option(name = "--use-content-merge", usage = "allow automatic conflict resolving within files")
-  void setUseContentMerge(boolean on) {
+  void setUseContentMerge(@SuppressWarnings("unused") boolean on) {
     contentMerge = InheritableBoolean.TRUE;
   }
 
   @Option(name = "--no-content-merge", usage = "don't allow automatic conflict resolving within files")
-  void setNoContentMerge(boolean on) {
+  void setNoContentMerge(@SuppressWarnings("unused") boolean on) {
     contentMerge = InheritableBoolean.FALSE;
   }
 
   @Option(name = "--require-change-id", aliases = {"--id"}, usage = "if change-id is required")
-  void setRequireChangeId(boolean on) {
+  void setRequireChangeId(@SuppressWarnings("unused") boolean on) {
     requireChangeID = InheritableBoolean.TRUE;
   }
 
   @Option(name = "--no-change-id", aliases = {"--nid"}, usage = "if change-id is not required")
-  void setNoChangeId(boolean on) {
+  void setNoChangeId(@SuppressWarnings("unused") boolean on) {
     requireChangeID = InheritableBoolean.FALSE;
   }