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    1   /*
    2    * Copyright 2009 Red Hat, Inc.
    3    *
    4    * Red Hat licenses this file to you under the Apache License, version 2.0
    5    * (the "License"); you may not use this file except in compliance with the
    6    * License.  You may obtain a copy of the License at:
    7    *
    8    *    http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
    13   * License for the specific language governing permissions and limitations
    14   * under the License.
    15   */
    16  package org.jboss.netty.handler.codec.serialization;
    17
    18  import java.io.EOFException;
    19  import java.io.IOException;
    20  import java.io.InputStream;
    21  import java.io.ObjectInputStream;
    22  import java.io.ObjectStreamClass;
    23  import java.io.StreamCorruptedException;
    24
    25  /**
    26   * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
    27   * @author <a href="http://gleamynode.net/">Trustin Lee</a>
    28   *
    29   * @version $Rev: 2080 $, $Date: 2010-01-26 18:04:19 +0900 (Tue, 26 Jan 2010) $
    30   *
    31   */
    32  class CompactObjectInputStream extends ObjectInputStream {
    33
    34      private final ClassLoader classLoader;
    35
    36      CompactObjectInputStream(InputStream in) throws IOException {
    37          this(in, null);
    38      }
    39
    40      CompactObjectInputStream(InputStream in, ClassLoader classLoader) throws IOException {
    41          super(in);
    42          this.classLoader = classLoader;
    43      }
    44
    45      @Override
    46      protected void readStreamHeader() throws IOException,
    47              StreamCorruptedException {
    48          int version = readByte() & 0xFF;
    49          if (version != STREAM_VERSION) {
    50              throw new StreamCorruptedException(
    51                      "Unsupported version: " + version);
    52          }
    53      }
    54
    55      @Override
    56      protected ObjectStreamClass readClassDescriptor()
    57              throws IOException, ClassNotFoundException {
    58          int type = read();
    59          if (type < 0) {
    60              throw new EOFException();
    61          }
    62          switch (type) {
    63          case CompactObjectOutputStream.TYPE_FAT_DESCRIPTOR:
    64              return super.readClassDescriptor();
    65          case CompactObjectOutputStream.TYPE_THIN_DESCRIPTOR:
    66              String className = readUTF();
    67              Class<?> clazz = loadClass(className);
    68              return ObjectStreamClass.lookup(clazz);
    69          default:
    70              throw new StreamCorruptedException(
    71                      "Unexpected class descriptor type: " + type);
    72          }
    73      }
    74
    75      @Override
    76      protected Class<?> resolveClass(ObjectStreamClass desc) throws IOException, ClassNotFoundException {
    77          String className = desc.getName();
    78          try {
    79              return loadClass(className);
    80          } catch (ClassNotFoundException ex) {
    81              return super.resolveClass(desc);
    82          }
    83      }
    84
    85      protected Class<?> loadClass(String className) throws ClassNotFoundException {
    86          Class<?> clazz;
    87          ClassLoader classLoader = this.classLoader;
    88          if (classLoader == null) {
    89              classLoader = Thread.currentThread().getContextClassLoader();
    90          }
    91
    92          if (classLoader != null) {
    93              clazz = classLoader.loadClass(className);
    94          } else {
    95              clazz = Class.forName(className);
    96          }
    97          return clazz;
    98      }
    99  }