org.sonar.java.checks.CatchOfThrowableOrErrorCheck Maven / Gradle / Ivy

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/*
 * SonarQube Java
 * Copyright (C) 2012 SonarSource
 * [email protected]
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
 */
package org.sonar.java.checks;

import org.sonar.api.rule.RuleKey;
import org.sonar.check.BelongsToProfile;
import org.sonar.check.Priority;
import org.sonar.check.Rule;
import org.sonar.plugins.java.api.JavaFileScanner;
import org.sonar.plugins.java.api.JavaFileScannerContext;
import org.sonar.plugins.java.api.tree.BaseTreeVisitor;
import org.sonar.plugins.java.api.tree.CatchTree;
import org.sonar.plugins.java.api.tree.ExpressionTree;
import org.sonar.plugins.java.api.tree.IdentifierTree;
import org.sonar.plugins.java.api.tree.MemberSelectExpressionTree;
import org.sonar.plugins.java.api.tree.Tree;
import org.sonar.plugins.java.api.tree.Tree.Kind;
import org.sonar.plugins.java.api.tree.UnionTypeTree;

@Rule(
  key = CatchOfThrowableOrErrorCheck.RULE_KEY,
  priority = Priority.BLOCKER,
  tags={"error-handling"})
@BelongsToProfile(title = "Sonar way", priority = Priority.BLOCKER)
public class CatchOfThrowableOrErrorCheck extends BaseTreeVisitor implements JavaFileScanner {

  private static final String ERROR = "Error";
  private static final String THROWABLE = "Throwable";

  public static final String RULE_KEY = "S1181";
  private final RuleKey ruleKey = RuleKey.of(CheckList.REPOSITORY_KEY, RULE_KEY);

  private JavaFileScannerContext context;

  @Override
  public void scanFile(JavaFileScannerContext context) {
    this.context = context;

    scan(context.getTree());
  }

  @Override
  public void visitCatch(CatchTree tree) {
    super.visitCatch(tree);

    Tree typeTree = tree.parameter().type();

    if (typeTree.is(Kind.UNION_TYPE)) {
      UnionTypeTree unionTypeTree = (UnionTypeTree) typeTree;
      for (Tree typeAlternativeTree : unionTypeTree.typeAlternatives()) {
        checkType(typeAlternativeTree);
      }
    } else {
      checkType(typeTree);
    }
  }

  private void checkType(Tree tree) {
    if (tree.is(Kind.IDENTIFIER)) {
      IdentifierTree identifierTree = (IdentifierTree) tree;

      if (isErrorOrThrowable(identifierTree.name())) {
        addIssue(tree, identifierTree.name());
      }
    } else if (tree.is(Kind.MEMBER_SELECT)) {
      MemberSelectExpressionTree memberSelectTree = (MemberSelectExpressionTree) tree;

      if (isErrorOrThrowable(memberSelectTree.identifier().name())) {
        ExpressionTree tree2 = memberSelectTree.expression();

        if (tree2.is(Kind.MEMBER_SELECT)) {
          MemberSelectExpressionTree memberSelectTree2 = (MemberSelectExpressionTree) tree2;

          if ("lang".equals(memberSelectTree2.identifier().name()) &&
            memberSelectTree2.expression().is(Kind.IDENTIFIER) &&
            "java".equals(((IdentifierTree) memberSelectTree2.expression()).name())) {
            addIssue(tree, memberSelectTree.identifier().name());
          }
        }
      }
    }
  }

  private static boolean isErrorOrThrowable(String name) {
    return ERROR.equals(name) || THROWABLE.equals(name);
  }

  private void addIssue(Tree tree, String type) {
    context.addIssue(tree, ruleKey, "Catch Exception instead of " + type + ".");
  }

}