InstantiatingObjectToGetClassObjectInspection.java

/*
 * Copyright 2003-2010 Dave Griffith, Bas Leijdekkers
 *
 * 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.siyeh.ig.performance;

import com.intellij.codeInspection.ProblemDescriptor;
import com.intellij.openapi.project.Project;
import com.intellij.psi.*;
import com.intellij.util.IncorrectOperationException;
import com.siyeh.InspectionGadgetsBundle;
import com.siyeh.ig.BaseInspection;
import com.siyeh.ig.BaseInspectionVisitor;
import com.siyeh.ig.InspectionGadgetsFix;
import com.siyeh.ig.PsiReplacementUtil;
import com.siyeh.ig.psiutils.StringUtils;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;

public class InstantiatingObjectToGetClassObjectInspection
  extends BaseInspection {

  @Override
  @NotNull
  public String getDisplayName() {
    return InspectionGadgetsBundle.message(
      "instantiating.object.to.get.class.object.display.name");
  }

  @Override
  public boolean isEnabledByDefault() {
    return true;
  }

  @Override
  @NotNull
  protected String buildErrorString(Object... infos) {
    return InspectionGadgetsBundle.message(
      "instantiating.object.to.get.class.object.problem.descriptor");
  }

  @Override
  protected InspectionGadgetsFix buildFix(Object... infos) {
    return new InstantiatingObjectToGetClassObjectFix();
  }

  private static class InstantiatingObjectToGetClassObjectFix
    extends InspectionGadgetsFix {

    @Override
    @NotNull
    public String getFamilyName() {
      return InspectionGadgetsBundle.message(
        "instantiating.object.to.get.class.object.replace.quickfix");
    }

    @Override
    public void doFix(Project project, ProblemDescriptor descriptor)
      throws IncorrectOperationException {
      final PsiMethodCallExpression expression =
        (PsiMethodCallExpression)descriptor.getPsiElement();
      final PsiReferenceExpression methodExpression =
        expression.getMethodExpression();
      final PsiExpression qualifier =
        methodExpression.getQualifierExpression();
      if (qualifier == null) {
        return;
      }
      final PsiType type = qualifier.getType();
      if (type == null) {
        return;
      }
      PsiReplacementUtil.replaceExpression(expression,
                                           getTypeText(type, new StringBuilder()) + ".class");
    }

    private static StringBuilder getTypeText(PsiType type,
                                             StringBuilder text) {
      if (type instanceof PsiArrayType) {
        text.append("[]");
        final PsiArrayType arrayType = (PsiArrayType)type;
        getTypeText(arrayType.getComponentType(), text);
      }
      else if (type instanceof PsiClassType) {
        final String canonicalText = type.getCanonicalText();
        final String typeText =
          StringUtils.stripAngleBrackets(canonicalText);
        text.insert(0, typeText);
      }
      else {
        text.insert(0, type.getCanonicalText());
      }
      return text;
    }
  }

  @Override
  public BaseInspectionVisitor buildVisitor() {
    return new InstantiatingObjectToGetClassObjectVisitor();
  }

  private static class InstantiatingObjectToGetClassObjectVisitor
    extends BaseInspectionVisitor {

    @Override
    public void visitMethodCallExpression(
      @NotNull PsiMethodCallExpression expression) {
      super.visitMethodCallExpression(expression);
      final PsiReferenceExpression methodExpression =
        expression.getMethodExpression();
      @NonNls final String methodName =
        methodExpression.getReferenceName();
      if (!"getClass".equals(methodName)) {
        return;
      }
      final PsiExpressionList argumentList = expression.getArgumentList();
      final PsiExpression[] args = argumentList.getExpressions();
      if (args.length != 0) {
        return;
      }
      final PsiExpression qualifier =
        methodExpression.getQualifierExpression();
      if (!(qualifier instanceof PsiNewExpression)) {
        return;
      }
      final PsiNewExpression newExpression = (PsiNewExpression)qualifier;
      if (newExpression.getAnonymousClass() != null) {
        return;
      }
      registerError(expression);
    }
  }
}