1 /*
2 * Copyright 2010 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.http.websocket;
17
18 import org.jboss.netty.buffer.ChannelBuffer;
19 import org.jboss.netty.channel.Channel;
20 import org.jboss.netty.channel.ChannelHandlerContext;
21 import org.jboss.netty.channel.ChannelHandler.Sharable;
22 import org.jboss.netty.handler.codec.oneone.OneToOneEncoder;
23
24 /**
25 * Encodes a {@link WebSocketFrame} into a {@link ChannelBuffer}.
26 * <p>
27 * For the detailed instruction on adding add Web Socket support to your HTTP
28 * server, take a look into the <tt>WebSocketServer</tt> example located in the
29 * {@code org.jboss.netty.example.http.websocket} package.
30 *
31 * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
32 * @author Mike Heath (mheath@apache.org)
33 * @author <a href="http://gleamynode.net/">Trustin Lee</a>
34 * @version $Rev: 2362 $, $Date: 2010-09-09 19:59:22 +0900 (Thu, 09 Sep 2010) $
35 *
36 * @apiviz.landmark
37 * @apiviz.uses org.jboss.netty.handler.codec.http.websocket.WebSocketFrame
38 */
39 @Sharable
40 public class WebSocketFrameEncoder extends OneToOneEncoder {
41
42 @Override
43 protected Object encode(ChannelHandlerContext ctx, Channel channel, Object msg) throws Exception {
44 if (msg instanceof WebSocketFrame) {
45 WebSocketFrame frame = (WebSocketFrame) msg;
46 int type = frame.getType();
47 if (frame.isText()) {
48 // Text frame
49 ChannelBuffer data = frame.getBinaryData();
50 ChannelBuffer encoded =
51 channel.getConfig().getBufferFactory().getBuffer(
52 data.order(), data.readableBytes() + 2);
53 encoded.writeByte((byte) type);
54 encoded.writeBytes(data, data.readerIndex(), data.readableBytes());
55 encoded.writeByte((byte) 0xFF);
56 return encoded;
57 } else {
58 // Binary frame
59 ChannelBuffer data = frame.getBinaryData();
60 int dataLen = data.readableBytes();
61 ChannelBuffer encoded =
62 channel.getConfig().getBufferFactory().getBuffer(
63 data.order(), dataLen + 5);
64
65 // Encode type.
66 encoded.writeByte((byte) type);
67
68 // Encode length.
69 int b1 = dataLen >>> 28 & 0x7F;
70 int b2 = dataLen >>> 14 & 0x7F;
71 int b3 = dataLen >>> 7 & 0x7F;
72 int b4 = dataLen & 0x7F;
73 if (b1 == 0) {
74 if (b2 == 0) {
75 if (b3 == 0) {
76 encoded.writeByte(b4);
77 } else {
78 encoded.writeByte(b3 | 0x80);
79 encoded.writeByte(b4);
80 }
81 } else {
82 encoded.writeByte(b2 | 0x80);
83 encoded.writeByte(b3 | 0x80);
84 encoded.writeByte(b4);
85 }
86 } else {
87 encoded.writeByte(b1 | 0x80);
88 encoded.writeByte(b2 | 0x80);
89 encoded.writeByte(b3 | 0x80);
90 encoded.writeByte(b4);
91 }
92
93 // Encode binary data.
94 encoded.writeBytes(data, data.readerIndex(), dataLen);
95 return encoded;
96 }
97 }
98 return msg;
99 }
100 }