notnull

java/java-impl/src/com/intellij/refactoring/changeClassSignature/ChangeClassSignatureProcessor.java

@@ -57,6 +57,7 @@ public class ChangeClassSignatureProcessor extends BaseRefactoringProcessor {
     return ChangeClassSignatureDialog.REFACTORING_NAME;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new ChangeClassSigntaureViewDescriptor(myClass);
   }

java/java-impl/src/com/intellij/refactoring/changeSignature/ChangeSignatureProcessor.java

@@ -114,6 +114,7 @@ public class ChangeSignatureProcessor extends ChangeSignatureProcessorBase {
                                   myPropagateParametersMethods, myPropagateExceptionsMethods);
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new ChangeSignatureViewDescriptor(getChangeInfo().getMethod());
   }

java/java-impl/src/com/intellij/refactoring/convertToInstanceMethod/ConvertToInstanceMethodProcessor.java

@@ -81,6 +81,7 @@ public class ConvertToInstanceMethodProcessor extends BaseRefactoringProcessor {
     return myTargetClass;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new MoveInstanceMethodViewDescriptor(myMethod, myTargetParameter, myTargetClass);
   }

java/java-impl/src/com/intellij/refactoring/encapsulateFields/EncapsulateFieldsProcessor.java

@@ -67,6 +67,7 @@ public class EncapsulateFieldsProcessor extends BaseRefactoringProcessor {
     myClass = myFields[0].getContainingClass();
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     PsiField[] fields = new PsiField[myFields.length];
     System.arraycopy(myFields, 0, fields, 0, myFields.length);

java/java-impl/src/com/intellij/refactoring/extractMethodObject/ExtractMethodObjectProcessor.java

@@ -92,6 +92,7 @@ public class ExtractMethodObjectProcessor extends BaseRefactoringProcessor {
     myElementFactory = JavaPsiFacade.getInstance(project).getElementFactory();
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(final UsageInfo[] usages) {
     return new ExtractMethodObjectViewDescriptor(getMethod());
   }

java/java-impl/src/com/intellij/refactoring/extractSuperclass/ExtractSuperBaseProcessor.java

@@ -62,6 +62,7 @@ public abstract class ExtractSuperBaseProcessor extends TurnRefsToSuperProcessor
     myJavaDocPolicy = javaDocPolicy;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new ExtractSuperClassViewDescriptor(myTargetDirectory, myClass, myMemberInfos);
   }

java/java-impl/src/com/intellij/refactoring/extractclass/ExtractClassProcessor.java

@@ -252,6 +252,7 @@ public class ExtractClassProcessor extends FixableUsagesRefactoringProcessor {
     return RefactorJBundle.message("extracted.class.command.name", newClassName);
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usageInfos) {
     return new ExtractClassUsageViewDescriptor(sourceClass);
   }

java/java-impl/src/com/intellij/refactoring/inheritanceToDelegation/InheritanceToDelegationProcessor.java

@@ -147,6 +147,7 @@ public class InheritanceToDelegationProcessor extends BaseRefactoringProcessor {
     return result;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new InheritanceToDelegationViewDescriptor(myClass);
   }

java/java-impl/src/com/intellij/refactoring/inline/InlineConstantFieldProcessor.java

@@ -53,6 +53,7 @@ public class InlineConstantFieldProcessor extends BaseRefactoringProcessor {
     myInlineThisOnly = isInlineThisOnly;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new InlineViewDescriptor(myField);
   }

java/java-impl/src/com/intellij/refactoring/inline/InlineMethodProcessor.java

@@ -97,6 +97,7 @@ public class InlineMethodProcessor extends BaseRefactoringProcessor {
     return RefactoringBundle.message("inline.method.command", myDescriptiveName);
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new InlineViewDescriptor(myMethod);
   }

java/java-impl/src/com/intellij/refactoring/inline/InlineParameterExpressionProcessor.java

@@ -79,6 +79,7 @@ public class InlineParameterExpressionProcessor extends BaseRefactoringProcessor
   protected void refreshElements(PsiElement[] elements) {
   }
 
+  @NotNull
   @Override
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new InlineViewDescriptor(myParameter);

java/java-impl/src/com/intellij/refactoring/inline/InlineToAnonymousClassProcessor.java

@@ -64,6 +64,7 @@ public class InlineToAnonymousClassProcessor extends BaseRefactoringProcessor {
     mySearchInNonJavaFiles = searchInNonJavaFiles;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new InlineViewDescriptor(myClass);
   }

java/java-impl/src/com/intellij/refactoring/inlineSuperClass/InlineSuperClassRefactoringProcessor.java

@@ -96,6 +96,7 @@ public class InlineSuperClassRefactoringProcessor extends FixableUsagesRefactori
     return members;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(final UsageInfo[] usages) {
     return new InlineSuperClassUsageViewDescriptor(mySuperClass);
   }

java/java-impl/src/com/intellij/refactoring/introduceParameter/IntroduceParameterProcessor.java

@@ -120,6 +120,7 @@ public class IntroduceParameterProcessor extends BaseRefactoringProcessor implem
     myInitializerWrapper = expressionToSearch == null ? null : new JavaExpressionWrapper(expressionToSearch);
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new IntroduceParameterViewDescriptor(myMethodToSearchFor);
   }

java/java-impl/src/com/intellij/refactoring/introduceparameterobject/IntroduceParameterObjectProcessor.java

@@ -129,6 +129,7 @@ public class IntroduceParameterObjectProcessor extends FixableUsagesRefactoringP
 
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usageInfos) {
     return new IntroduceParameterObjectUsageViewDescriptor(method);
   }

java/java-impl/src/com/intellij/refactoring/invertBoolean/InvertBooleanProcessor.java

@@ -16,7 +16,6 @@
 package com.intellij.refactoring.invertBoolean;
 
 import com.intellij.codeInsight.CodeInsightServicesUtil;
-import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Ref;
@@ -25,12 +24,9 @@ import com.intellij.psi.search.searches.MethodReferencesSearch;
 import com.intellij.psi.search.searches.OverridingMethodsSearch;
 import com.intellij.psi.search.searches.ReferencesSearch;
 import com.intellij.refactoring.BaseRefactoringProcessor;
-import com.intellij.refactoring.RefactoringBundle;
 import com.intellij.refactoring.listeners.RefactoringElementListener;
 import com.intellij.refactoring.rename.RenameProcessor;
-import com.intellij.refactoring.rename.RenamePsiElementProcessor;
 import com.intellij.refactoring.rename.RenameUtil;
-import com.intellij.refactoring.util.CommonRefactoringUtil;
 import com.intellij.refactoring.util.MoveRenameUsageInfo;
 import com.intellij.usageView.UsageInfo;
 import com.intellij.usageView.UsageViewDescriptor;
@@ -66,6 +62,7 @@ public class InvertBooleanProcessor extends BaseRefactoringProcessor {
     mySmartPointerManager = SmartPointerManager.getInstance(project);
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new InvertBooleanUsageViewDescriptor(myElement);
   }

java/java-impl/src/com/intellij/refactoring/makeStatic/MakeMethodOrClassStaticProcessor.java

@@ -66,6 +66,7 @@ public abstract class MakeMethodOrClassStaticProcessor<T extends PsiTypeParamete
     mySettings = settings;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new MakeMethodOrClassStaticViewDescriptor(myMember);
   }

java/java-impl/src/com/intellij/refactoring/memberPushDown/PushDownProcessor.java

@@ -69,6 +69,7 @@ public class PushDownProcessor extends BaseRefactoringProcessor {
     return JavaPushDownHandler.REFACTORING_NAME;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new PushDownUsageViewDescriptor(myClass);
   }

java/java-impl/src/com/intellij/refactoring/migration/MigrationProcessor.java

@@ -48,6 +48,7 @@ class MigrationProcessor extends BaseRefactoringProcessor {
     myPsiMigration = startMigration(project);
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new MigrationUsagesViewDescriptor(myMigrationMap, false);
   }

java/java-impl/src/com/intellij/refactoring/move/moveClassesOrPackages/MoveClassToInnerProcessor.java

@@ -93,6 +93,7 @@ public class MoveClassToInnerProcessor extends BaseRefactoringProcessor {
     }
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new MoveMultipleElementsViewDescriptor(myClassesToMove, myTargetClass.getQualifiedName());
   }

java/java-impl/src/com/intellij/refactoring/move/moveClassesOrPackages/MoveClassesOrPackagesProcessor.java

@@ -112,6 +112,7 @@ public class MoveClassesOrPackagesProcessor extends BaseRefactoringProcessor {
     myMoveCallback = moveCallback;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     PsiElement[] elements = new PsiElement[myElementsToMove.length];
     System.arraycopy(myElementsToMove, 0, elements, 0, myElementsToMove.length);

java/java-impl/src/com/intellij/refactoring/move/moveInstanceMethod/MoveInstanceMethodProcessor.java

@@ -79,6 +79,7 @@ public class MoveInstanceMethodProcessor extends BaseRefactoringProcessor{
     myNewVisibility = newVisibility;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new MoveInstanceMethodViewDescriptor(myMethod, myTargetVariable, myTargetClass);
   }

java/java-impl/src/com/intellij/refactoring/removemiddleman/RemoveMiddlemanProcessor.java

@@ -55,6 +55,7 @@ public class RemoveMiddlemanProcessor extends FixableUsagesRefactoringProcessor
     myDelegateMethodInfos = memberInfos;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usageInfos) {
     return new RemoveMiddlemanUsageViewDescriptor(field);
   }

java/java-impl/src/com/intellij/refactoring/replaceConstructorWithBuilder/ReplaceConstructorWithBuilderProcessor.java

@@ -81,6 +81,7 @@ public class ReplaceConstructorWithBuilderProcessor extends FixableUsagesRefacto
     myCreateNewBuilderClass = createNewBuilderClass;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(final UsageInfo[] usages) {
     return new ReplaceConstructorWithBuilderViewDescriptor();
   }

java/java-impl/src/com/intellij/refactoring/replaceConstructorWithFactory/ReplaceConstructorWithFactoryProcessor.java

@@ -77,6 +77,7 @@ public class ReplaceConstructorWithFactoryProcessor extends BaseRefactoringProce
     return result;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     if (myConstructor != null) {
       return new ReplaceConstructorWithFactoryViewDescriptor(myConstructor);

java/java-impl/src/com/intellij/refactoring/turnRefsToSuper/TurnRefsToSuperProcessor.java

@@ -55,6 +55,7 @@ public class TurnRefsToSuperProcessor extends TurnRefsToSuperProcessorBase {
                                      UsageViewUtil.getDescriptiveName(myClass), UsageViewUtil.getDescriptiveName(mySuper));
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new RefsToSuperViewDescriptor(myClass, mySuper);
   }

java/java-impl/src/com/intellij/refactoring/typeCook/TypeCookProcessor.java

@@ -47,6 +47,7 @@ public class TypeCookProcessor extends BaseRefactoringProcessor {
     mySettings = settings;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new TypeCookViewDescriptor(myElements);
   }

java/java-impl/src/com/intellij/refactoring/typeMigration/TypeMigrationProcessor.java

@@ -86,6 +86,7 @@ public class TypeMigrationProcessor extends BaseRefactoringProcessor {
     processor.run();
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new TypeMigrationViewDescriptor(myRoot[0]);
   }

java/java-impl/src/com/intellij/refactoring/wrapreturnvalue/WrapReturnValueProcessor.java

@@ -116,6 +116,7 @@ public class WrapReturnValueProcessor extends FixableUsagesRefactoringProcessor
     return "";
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usageInfos) {
     return new WrapReturnValueUsageViewDescriptor(method, usageInfos);
   }

java/java-tests/testSrc/com/intellij/refactoring/InheritanceToDelegationTest.java

@@ -1,8 +1,6 @@
 package com.intellij.refactoring;
 
 import com.intellij.JavaTestUtil;
-import com.intellij.openapi.projectRoots.Sdk;
-import com.intellij.openapi.projectRoots.impl.JavaSdkImpl;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.PsiClass;
 import com.intellij.psi.PsiMethod;

platform/lang-impl/src/com/intellij/refactoring/move/moveFilesOrDirectories/MoveFilesOrDirectoriesProcessor.java

@@ -83,6 +83,7 @@ public class MoveFilesOrDirectoriesProcessor extends BaseRefactoringProcessor {
     myMoveCallback = moveCallback;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new MoveFilesOrDirectoriesViewDescriptor(myElementsToMove, myNewParent);
   }

platform/lang-impl/src/com/intellij/refactoring/rename/PsiElementRenameHandler.java

@@ -98,14 +98,15 @@ public class PsiElementRenameHandler implements RenameHandler {
   static boolean canRename(Project project, Editor editor, PsiElement element) throws CommonRefactoringUtil.RefactoringErrorHintException {
     String message = renameabilityStatus(project, element);
     if (message != null) {
-      if (message.length() > 0) showErrorMessage(project, editor, message);
+      if (!message.isEmpty()) showErrorMessage(project, editor, message);
 
       return false;
     }
     return true;
   }
 
-  static @Nullable String renameabilityStatus(Project project, PsiElement element) {
+  @Nullable
+  static String renameabilityStatus(Project project, PsiElement element) {
     if (element == null) return "";
 
     boolean hasRenameProcessor = RenamePsiElementProcessor.forElement(element) != RenamePsiElementProcessor.DEFAULT;

platform/lang-impl/src/com/intellij/refactoring/rename/RenameProcessor.java

@@ -251,6 +251,7 @@ public class RenameProcessor extends BaseRefactoringProcessor {
       .message("renaming.0.1.to.2", UsageViewUtil.getType(myPrimaryElement), UsageViewUtil.getDescriptiveName(myPrimaryElement), newName);
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new RenameViewDescriptor(myAllRenames);
   }

platform/lang-impl/src/com/intellij/refactoring/safeDelete/SafeDeleteProcessor.java

@@ -72,6 +72,7 @@ public class SafeDeleteProcessor extends BaseRefactoringProcessor {
     mySearchNonJava = isSearchNonJava;
   }
 
+  @NotNull
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new SafeDeleteUsageViewDescriptor(myElements);
   }

plugins/groovy/src/org/jetbrains/plugins/groovy/refactoring/changeSignature/GrChangeSignatureProcessor.java

@@ -29,6 +29,7 @@ import com.intellij.usageView.UsageInfo;
 import com.intellij.usageView.UsageViewDescriptor;
 import com.intellij.util.containers.HashSet;
 import com.intellij.util.containers.MultiMap;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.Arrays;
 import java.util.Collection;
@@ -50,6 +51,7 @@ public class GrChangeSignatureProcessor extends ChangeSignatureProcessorBase {
     return (GrChangeInfoImpl)super.getChangeInfo();
   }
 
+  @NotNull
   @Override
   protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usages) {
     return new ChangeSignatureViewDescriptor(getChangeInfo().getMethod());

plugins/groovy/test/org/jetbrains/plugins/groovy/lang/GppCategoryTest.groovy

@@ -19,11 +19,13 @@ import com.intellij.psi.PsiReference
 import com.intellij.testFramework.LightProjectDescriptor
 import com.intellij.testFramework.fixtures.LightCodeInsightFixtureTestCase
 import org.jetbrains.plugins.groovy.lang.psi.api.statements.typedef.members.GrGdkMethod
+import org.jetbrains.annotations.NotNull
 
 /**
  * @author peter
  */
 class GppCategoryTest extends LightCodeInsightFixtureTestCase {
+  @NotNull
   @Override
   protected LightProjectDescriptor getProjectDescriptor() {
     return GppProjectDescriptor.instance

plugins/xpath/xpath-lang/src/org/intellij/lang/xpath/xslt/refactoring/introduceParameter/IntroduceParameterProcessor.java

@@ -62,6 +62,7 @@ class IntroduceParameterProcessor extends BaseRefactoringProcessor {
     }
 
 
+    @NotNull
     protected UsageViewDescriptor createUsageViewDescriptor(UsageInfo[] usageInfos) {
         return new MyUsageViewDescriptorAdapter();
     }