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    1   /*
    2    *  Licensed to the Apache Software Foundation (ASF) under one
    3    *  or more contributor license agreements.  See the NOTICE file
    4    *  distributed with this work for additional information
    5    *  regarding copyright ownership.  The ASF licenses this file
    6    *  to you under the Apache License, Version 2.0 (the
    7    *  "License"); you may not use this file except in compliance
    8    *  with the License.  You may obtain a copy of the License at
    9    *
    10   *    http://www.apache.org/licenses/LICENSE-2.0
    11   *
    12   *  Unless required by applicable law or agreed to in writing,
    13   *  software distributed under the License is distributed on an
    14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    15   *  KIND, either express or implied.  See the License for the
    16   *  specific language governing permissions and limitations
    17   *  under the License.
    18   *
    19   */
    20  package org.apache.mina.filter.codec.serialization;
    21
    22  import java.io.Serializable;
    23
    24  import org.apache.mina.common.BufferDataException;
    25  import org.apache.mina.common.ByteBuffer;
    26  import org.apache.mina.common.IoSession;
    27  import org.apache.mina.filter.codec.CumulativeProtocolDecoder;
    28  import org.apache.mina.filter.codec.ProtocolDecoder;
    29  import org.apache.mina.filter.codec.ProtocolDecoderOutput;
    30
    31  /**
    32   * A {@link ProtocolDecoder} which deserializes {@link Serializable} Java
    33   * objects using {@link ByteBuffer#getObject(ClassLoader)}.
    34   *
    35   * @author The Apache Directory Project (mina-dev@directory.apache.org)
    36   * @version $Rev: 555855 $, $Date: 2007-07-13 12:19:00 +0900 (Fri, 13 Jul 2007) $
    37   */
    38  public class ObjectSerializationDecoder extends CumulativeProtocolDecoder {
    39      private final ClassLoader classLoader;
    40
    41      private int maxObjectSize = 1048576; // 1MB
    42
    43      /**
    44       * Creates a new instance with the {@link ClassLoader} of
    45       * the current thread.
    46       */
    47      public ObjectSerializationDecoder() {
    48          this(Thread.currentThread().getContextClassLoader());
    49      }
    50
    51      /**
    52       * Creates a new instance with the specified {@link ClassLoader}.
    53       */
    54      public ObjectSerializationDecoder(ClassLoader classLoader) {
    55          if (classLoader == null) {
    56              throw new NullPointerException("classLoader");
    57          }
    58          this.classLoader = classLoader;
    59      }
    60
    61      /**
    62       * Returns the allowed maximum size of the object to be decoded.
    63       * If the size of the object to be decoded exceeds this value, this
    64       * decoder will throw a {@link BufferDataException}.  The default
    65       * value is <tt>1048576</tt> (1MB).
    66       */
    67      public int getMaxObjectSize() {
    68          return maxObjectSize;
    69      }
    70
    71      /**
    72       * Sets the allowed maximum size of the object to be decoded.
    73       * If the size of the object to be decoded exceeds this value, this
    74       * decoder will throw a {@link BufferDataException}.  The default
    75       * value is <tt>1048576</tt> (1MB).
    76       */
    77      public void setMaxObjectSize(int maxObjectSize) {
    78          if (maxObjectSize <= 0) {
    79              throw new IllegalArgumentException("maxObjectSize: "
    80                      + maxObjectSize);
    81          }
    82
    83          this.maxObjectSize = maxObjectSize;
    84      }
    85
    86      protected boolean doDecode(IoSession session, ByteBuffer in,
    87              ProtocolDecoderOutput out) throws Exception {
    88          if (!in.prefixedDataAvailable(4, maxObjectSize)) {
    89              return false;
    90          }
    91
    92          out.write(in.getObject(classLoader));
    93          return true;
    94      }
    95  }