ThrowablePrintedToSystemOutInspection.java

/*
 * Copyright 2000-2014 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.siyeh.ig.maturity;

import com.intellij.psi.*;
import com.siyeh.InspectionGadgetsBundle;
import com.siyeh.ig.BaseInspection;
import com.siyeh.ig.BaseInspectionVisitor;
import com.siyeh.ig.psiutils.TypeUtils;
import org.jetbrains.annotations.Nls;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;

/**
 * @author Bas Leijdekkers
 */
public class ThrowablePrintedToSystemOutInspection extends BaseInspection {
  @Nls
  @NotNull
  @Override
  public String getDisplayName() {
    return InspectionGadgetsBundle.message("throwable.printed.to.system.out.display.name");
  }

  @NotNull
  @Override
  protected String buildErrorString(Object... infos) {
    final String fieldName = (String)infos[0];
    final String methodName = (String)infos[1];
    return InspectionGadgetsBundle.message("throwable.printed.to.system.out.problem.descriptor", fieldName, methodName);
  }

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

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

  private static class ThrowablePrintedToSystemOutVisitor extends BaseInspectionVisitor {

    @Override
    public void visitMethodCallExpression(PsiMethodCallExpression expression) {
      super.visitMethodCallExpression(expression);
      final PsiReferenceExpression methodExpression = expression.getMethodExpression();
      @NonNls final String methodName = methodExpression.getReferenceName();
      if (!"print".equals(methodName) && !"println".equals(methodName)) {
        return;
      }
      final PsiExpressionList argumentList = expression.getArgumentList();
      final PsiExpression[] arguments = argumentList.getExpressions();
      if (arguments.length != 1) {
        return;
      }
      final PsiExpression argument = arguments[0];
      if (!TypeUtils.expressionHasTypeOrSubtype(argument, CommonClassNames.JAVA_LANG_THROWABLE)) {
        return;
      }
      final PsiMethod method = expression.resolveMethod();
      if (method == null) {
        return;
      }
      final PsiExpression qualifier = methodExpression.getQualifierExpression();
      if (!(qualifier instanceof PsiReferenceExpression)) {
        return;
      }
      final PsiReferenceExpression qualifierReference = (PsiReferenceExpression)qualifier;
      final PsiElement target = qualifierReference.resolve();
      if (!(target instanceof PsiField)) {
        return;
      }
      final PsiField field = (PsiField)target;
      @NonNls final String fieldName = field.getName();
      if (!"out".equals(fieldName) && !"err".equals(fieldName)) {
        return;
      }
      final PsiClass aClass = field.getContainingClass();
      if (aClass == null || !"java.lang.System".equals(aClass.getQualifiedName())) {
        return;
      }
      registerError(argument, fieldName, methodName);
    }
  }
}