1 /*
2 * Copyright 2012 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the 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 io.netty.handler.codec.serialization;
17
18 import io.netty.buffer.ByteBuf;
19 import io.netty.buffer.ByteBufOutputStream;
20 import io.netty.channel.ChannelHandler.Sharable;
21 import io.netty.channel.ChannelHandlerContext;
22 import io.netty.handler.codec.MessageToByteEncoder;
23
24 import java.io.ObjectInputStream;
25 import java.io.ObjectOutputStream;
26 import java.io.Serializable;
27
28 /**
29 * An encoder which serializes a Java object into a {@link ByteBuf}.
30 * <p>
31 * Please note that the serialized form this encoder produces is not
32 * compatible with the standard {@link ObjectInputStream}. Please use
33 * {@link ObjectDecoder} or {@link ObjectDecoderInputStream} to ensure the
34 * interoperability with this encoder.
35 */
36 @Sharable
37 public class ObjectEncoder extends MessageToByteEncoder<Serializable> {
38 private static final byte[] LENGTH_PLACEHOLDER = new byte[4];
39
40 @Override
41 protected void encode(ChannelHandlerContext ctx, Serializable msg, ByteBuf out) throws Exception {
42 int startIdx = out.writerIndex();
43
44 ByteBufOutputStream bout = new ByteBufOutputStream(out);
45 ObjectOutputStream oout = null;
46 try {
47 bout.write(LENGTH_PLACEHOLDER);
48 oout = new CompactObjectOutputStream(bout);
49 oout.writeObject(msg);
50 oout.flush();
51 } finally {
52 if (oout != null) {
53 oout.close();
54 } else {
55 bout.close();
56 }
57 }
58
59 int endIdx = out.writerIndex();
60
61 out.setInt(startIdx, endIdx - startIdx - 4);
62 }
63 }