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/*
* Copyright 2000-2012 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.intellij.codeInspection;
import com.intellij.codeInsight.daemon.GroupNames;
import com.intellij.codeInsight.intention.HighPriorityAction;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.project.Project;
import com.intellij.pom.java.LanguageLevel;
import com.intellij.psi.*;
import com.intellij.psi.impl.source.resolve.graphInference.InferenceSession;
import com.intellij.psi.infos.CandidateInfo;
import com.intellij.psi.infos.MethodCandidateInfo;
import com.intellij.psi.scope.conflictResolvers.JavaMethodsConflictResolver;
import com.intellij.psi.util.PsiTreeUtil;
import com.intellij.psi.util.PsiUtil;
import com.intellij.util.ArrayUtil;
import org.jetbrains.annotations.Nls;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* User: anna
*/
public class RedundantLambdaCodeBlockInspection extends BaseJavaBatchLocalInspectionTool {
public static final Logger LOG = Logger.getInstance("#" + RedundantLambdaCodeBlockInspection.class.getName());
@Nls
@NotNull
@Override
public String getGroupDisplayName() {
return GroupNames.LANGUAGE_LEVEL_SPECIFIC_GROUP_NAME;
}
@Nls
@NotNull
@Override
public String getDisplayName() {
return "Statement lambda can be replaced with expression lambda";
}
@Override
public boolean isEnabledByDefault() {
return true;
}
@NotNull
@Override
public String getShortName() {
return "CodeBlock2Expr";
}
@NotNull
@Override
public PsiElementVisitor buildVisitor(@NotNull final ProblemsHolder holder, boolean isOnTheFly) {
return new JavaElementVisitor() {
@Override
public void visitLambdaExpression(PsiLambdaExpression expression) {
super.visitLambdaExpression(expression);
final PsiElement body = expression.getBody();
if (body instanceof PsiCodeBlock) {
PsiExpression psiExpression = getExpression((PsiCodeBlock)body);
if (psiExpression != null) {
if (!expression.isVoidCompatible() && LambdaUtil.isExpressionStatementExpression(psiExpression)) {
final PsiElement parent = PsiUtil.skipParenthesizedExprUp(expression.getParent());
if (parent instanceof PsiExpressionList) {
final PsiElement gParent = parent.getParent();
if (gParent instanceof PsiCallExpression) {
final CandidateInfo[] candidates = PsiResolveHelper.SERVICE.getInstance(gParent.getProject())
.getReferencedMethodCandidates((PsiCallExpression)gParent, false);
if (candidates.length > 1) {
final List<CandidateInfo> info = new ArrayList<CandidateInfo>(Arrays.asList(candidates));
final LanguageLevel level = PsiUtil.getLanguageLevel(parent);
final JavaMethodsConflictResolver conflictResolver = new JavaMethodsConflictResolver((PsiExpressionList)parent, level);
final int applicability = conflictResolver.checkApplicability(info);
conflictResolver.checkSpecifics(info, applicability, level);
if (info.size() > 1) {
return;
}
}
}
}
}
final PsiElement errorElement;
final PsiElement parent = psiExpression.getParent();
if (parent instanceof PsiReturnStatement) {
errorElement = parent.getFirstChild();
} else {
errorElement = body.getFirstChild();
}
holder.registerProblem(errorElement, "Statement lambda can be replaced with expression lambda",
ProblemHighlightType.LIKE_UNUSED_SYMBOL, new ReplaceWithExprFix());
}
}
}
};
}
@Nullable
private static PsiExpression getExpression(PsiCodeBlock body) {
final PsiStatement[] statements = body.getStatements();
if (statements.length == 1) {
if (statements[0] instanceof PsiBlockStatement) {
return getExpression(((PsiBlockStatement)statements[0]).getCodeBlock());
}
if (statements[0] instanceof PsiReturnStatement || statements[0] instanceof PsiExpressionStatement) {
if (statements[0] instanceof PsiReturnStatement) {
final PsiReturnStatement returnStatement = (PsiReturnStatement)statements[0];
return returnStatement.getReturnValue();
}
else {
return ((PsiExpressionStatement)statements[0]).getExpression();
}
}
}
return null;
}
private static class ReplaceWithExprFix implements LocalQuickFix, HighPriorityAction {
@NotNull
@Override
public String getName() {
return "Replace with expression lambda";
}
@NotNull
@Override
public String getFamilyName() {
return getName();
}
@Override
public void applyFix(@NotNull Project project, @NotNull ProblemDescriptor descriptor) {
final PsiElement element = descriptor.getPsiElement();
if (element != null) {
final PsiLambdaExpression lambdaExpression = PsiTreeUtil.getParentOfType(element, PsiLambdaExpression.class);
if (lambdaExpression != null) {
final PsiElement body = lambdaExpression.getBody();
if (body != null) {
PsiExpression expression = getExpression((PsiCodeBlock)body);
if (expression != null) {
body.replace(expression);
}
}
}
}
}
}
}
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