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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.codec.delimited.serialization;
    21
    22  import java.io.IOException;
    23  import java.io.ObjectOutputStream;
    24  import java.io.Serializable;
    25  import java.nio.ByteBuffer;
    26
    27  import org.apache.mina.codec.delimited.ByteBufferEncoder;
    28  import org.apache.mina.util.ByteBufferOutputStream;
    29
    30  /**
    31   * Encoder providing the built-in Java-serialization.
    32   *
    33   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
    34   */
    35  public class JavaNativeMessageEncoder<OUT extends Serializable> extends ByteBufferEncoder<OUT> {
    36      @Override
    37      public ByteBuffer encode(OUT message) {
    38          // avoid the copy done in Transcoder
    39          return serialize(message);
    40      }
    41
    42      private OUT lastObject;
    43
    44      private ByteBuffer lastSerialized;
    45
    46      @Override
    47      public int getEncodedSize(OUT message) {
    48          return serialize(message).remaining();
    49      }
    50
    51      private ByteBuffer serialize(OUT message) {
    52          if (message != lastObject) {
    53              ByteBufferOutputStream ebbosa = new ByteBufferOutputStream();
    54              ebbosa.setElastic(true);
    55              try {
    56                  ObjectOutputStream oos = new ObjectOutputStream(ebbosa);
    57                  oos.writeObject(message);
    58                  oos.close();
    59                  lastObject = message;
    60                  lastSerialized = ebbosa.getByteBuffer();
    61              } catch (IOException e) {
    62                  throw new IllegalStateException("Serialization exception", e);
    63              }
    64          }
    65          return lastSerialized;
    66      }
    67
    68      @Override
    69      public void writeTo(OUT message, ByteBuffer buffer) {
    70          buffer.put(serialize(message));
    71      }
    72  }