Line data    Source code

       1             : // Copyright (C) 2016 The Android Open Source Project
       2             : //
       3             : // Licensed under the Apache License, Version 2.0 (the "License");
       4             : // you may not use this file except in compliance with the License.
       5             : // You may obtain a copy of the License at
       6             : //
       7             : // http://www.apache.org/licenses/LICENSE-2.0
       8             : //
       9             : // Unless required by applicable law or agreed to in writing, software
      10             : // distributed under the License is distributed on an "AS IS" BASIS,
      11             : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             : // See the License for the specific language governing permissions and
      13             : // limitations under the License.
      14             : 
      15             : package com.google.gerrit.server.plugins;
      16             : 
      17             : import com.google.common.io.ByteStreams;
      18             : import java.io.IOException;
      19             : import java.io.InputStream;
      20             : import java.net.URL;
      21             : import java.util.Enumeration;
      22             : 
      23             : public class DelegatingClassLoader extends ClassLoader {
      24             :   private final ClassLoader target;
      25             : 
      26             :   public DelegatingClassLoader(ClassLoader parent, ClassLoader target) {
      27           0 :     super(parent);
      28           0 :     this.target = target;
      29           0 :   }
      30             : 
      31             :   @Override
      32             :   public Class<?> findClass(String name) throws ClassNotFoundException {
      33           0 :     String path = name.replace('.', '/') + ".class";
      34           0 :     try (InputStream resource = target.getResourceAsStream(path)) {
      35           0 :       if (resource != null) {
      36             :         try {
      37           0 :           byte[] bytes = ByteStreams.toByteArray(resource);
      38           0 :           return defineClass(name, bytes, 0, bytes.length);
      39           0 :         } catch (IOException e) {
      40             :           // throws ClassNotFoundException later
      41             :         }
      42             :       }
      43           0 :     } catch (IOException e) {
      44             :       // throws ClassNotFoundException later
      45           0 :     }
      46           0 :     throw new ClassNotFoundException(name);
      47             :   }
      48             : 
      49             :   @Override
      50             :   public URL getResource(String name) {
      51           0 :     URL rtn = getParent().getResource(name);
      52           0 :     if (rtn == null) {
      53           0 :       rtn = target.getResource(name);
      54             :     }
      55           0 :     return rtn;
      56             :   }
      57             : 
      58             :   @Override
      59             :   public Enumeration<URL> getResources(String name) throws IOException {
      60           0 :     Enumeration<URL> rtn = getParent().getResources(name);
      61           0 :     if (rtn == null) {
      62           0 :       rtn = target.getResources(name);
      63             :     }
      64           0 :     return rtn;
      65             :   }
      66             : 
      67             :   @Override
      68             :   public InputStream getResourceAsStream(String name) {
      69           0 :     InputStream rtn = getParent().getResourceAsStream(name);
      70           0 :     if (rtn == null) {
      71           0 :       rtn = target.getResourceAsStream(name);
      72             :     }
      73           0 :     return rtn;
      74             :   }
      75             : }