content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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 org.apache.commons.io.input;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.ObjectInputStream;
  import java.io.ObjectStreamClass;
  import java.io.StreamCorruptedException;
  import java.lang.reflect.Proxy;
  
  /**
   * A special ObjectInputStream that loads a class based on a specified
   * <code>ClassLoader</code> rather than the system default.
   * <p>
   * This is useful in dynamic container environments.
   *
   * @version $Id: ClassLoaderObjectInputStream.java 1304052 2012-03-22 20:55:29Z ggregory $
   * @since 1.1
   */
  public class ClassLoaderObjectInputStream extends ObjectInputStream {
  
      /** The class loader to use. */
      private final ClassLoader classLoader;
  
      /**
       * Constructs a new ClassLoaderObjectInputStream.
       *
       * @param classLoader  the ClassLoader from which classes should be loaded
       * @param inputStream  the InputStream to work on
       * @throws IOException in case of an I/O error
       * @throws StreamCorruptedException if the stream is corrupted
       */
      public ClassLoaderObjectInputStream(
              ClassLoader classLoader, InputStream inputStream)
              throws IOException, StreamCorruptedException {
          super(inputStream);
          this.classLoader = classLoader;
      }
  
      /**
       * Resolve a class specified by the descriptor using the
       * specified ClassLoader or the super ClassLoader.
       *
       * @param objectStreamClass  descriptor of the class
       * @return the Class object described by the ObjectStreamClass
       * @throws IOException in case of an I/O error
       * @throws ClassNotFoundException if the Class cannot be found
       */
      @Override
      protected Class<?> resolveClass(ObjectStreamClass objectStreamClass)
              throws IOException, ClassNotFoundException {
          
          Class<?> clazz = Class.forName(objectStreamClass.getName(), false, classLoader);
  
          if (clazz != null) {
              // the classloader knows of the class
              return clazz;
          } else {
              // classloader knows not of class, let the super classloader do it
              return super.resolveClass(objectStreamClass);
          }
      }
  
      /**
       * Create a proxy class that implements the specified interfaces using
       * the specified ClassLoader or the super ClassLoader.
       *
       * @param interfaces the interfaces to implement
       * @return a proxy class implementing the interfaces
       * @throws IOException in case of an I/O error
       * @throws ClassNotFoundException if the Class cannot be found
       * @see java.io.ObjectInputStream#resolveProxyClass(java.lang.String[])
       * @since 2.1
       */
      @Override
      protected Class<?> resolveProxyClass(String[] interfaces) throws IOException,
              ClassNotFoundException {
          Class<?>[] interfaceClasses = new Class[interfaces.length];
          for (int i = 0; i < interfaces.length; i++) {
              interfaceClasses[i] = Class.forName(interfaces[i], false, classLoader);
          }
          try {
              return Proxy.getProxyClass(classLoader, interfaceClasses);
          } catch (IllegalArgumentException e) {
              return super.resolveProxyClass(interfaces);
          }
      }
      
  }
  