content: /*
   * Copyright 1999-2017 Alibaba Group.
   *
   * 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.alibaba.p3c.pmd.lang.java.rule.set;
  
  import java.util.List;
  
  import com.alibaba.p3c.pmd.lang.java.rule.AbstractAliRule;
  
  import net.sourceforge.pmd.lang.ast.Node;
  import net.sourceforge.pmd.lang.java.ast.ASTClassOrInterfaceDeclaration;
  import net.sourceforge.pmd.lang.java.ast.ASTPrimaryExpression;
  import net.sourceforge.pmd.lang.java.ast.ASTPrimaryPrefix;
  import net.sourceforge.pmd.lang.java.ast.ASTPrimarySuffix;
  import org.jaxen.JaxenException;
  
  /**
   * [Mandatory] Do not use toArray method without arguments. Since the return type is Object[], ClassCastException will
   * be thrown when casting it to a different array type。
   *
   * @author shengfang.gsf
   * @date 2016/12/13
   */
  public class ClassCastExceptionWithToArrayRule extends AbstractAliRule {
  
      private static final String XPATH
          = "//CastExpression[Type/ReferenceType/ClassOrInterfaceType[@Image !=\"Object\"]]/PrimaryExpression";
  
      @Override
      public Object visit(ASTClassOrInterfaceDeclaration node, Object data) {
          if (node.isInterface()) {
              return data;
          }
          try {
              List<Node> nodes = node.findChildNodesWithXPath(XPATH);
              for (Node item : nodes) {
                  if (!(item instanceof ASTPrimaryExpression)) {
                      continue;
                  }
                  ASTPrimaryExpression primaryExpression = (ASTPrimaryExpression)item;
                  List<ASTPrimaryPrefix> primaryPrefixs =
                      primaryExpression.findChildrenOfType(ASTPrimaryPrefix.class);
                  List<ASTPrimarySuffix> primarySuffixs =
                      primaryExpression.findChildrenOfType(ASTPrimarySuffix.class);
                  if (primaryPrefixs == null || primarySuffixs == null || primaryPrefixs.isEmpty()
                      || primarySuffixs.isEmpty()) {
                      continue;
                  }
                  ASTPrimaryPrefix prefix = primaryPrefixs.get(0);
                  ASTPrimarySuffix suffix = primarySuffixs.get(0);
                  if (prefix.jjtGetNumChildren() == 0) {
                      continue;
                  }
                  Node prefixChildNode = prefix.jjtGetChild(0);
                  String childName = prefixChildNode.getImage();
                  if (childName == null) {
                      continue;
                  }
                  if (childName.endsWith(".toArray") && suffix.getArgumentCount() == 0
                      && primarySuffixs.size() == 1) {
                      addViolationWithMessage(data, item,
                          "java.set.ClassCastExceptionWithToArrayRule.violation.msg",
                          new Object[] {childName});
                  }
              }
  
          } catch (JaxenException e) {
              e.printStackTrace();
          }
          return super.visit(node, data);
      }
  }
  