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 org.jboss.netty.handler.codec.http.websocketx;
17
18 import org.jboss.netty.buffer.ChannelBuffer;
19 import org.jboss.netty.channel.Channel;
20 import org.jboss.netty.channel.ChannelHandler.Sharable;
21 import org.jboss.netty.channel.ChannelHandlerContext;
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 server, take a look into the
28 * <tt>WebSocketServer</tt> example located in the {@code org.jboss.netty.example.http.websocket} package.
29 *
30 * @apiviz.landmark
31 * @apiviz.uses org.jboss.netty.handler.codec.http.websocket.WebSocketFrame
32 */
33 @Sharable
34 public class WebSocket00FrameEncoder extends OneToOneEncoder {
35
36 @Override
37 protected Object encode(ChannelHandlerContext ctx, Channel channel, Object msg) throws Exception {
38 if (msg instanceof WebSocketFrame) {
39 WebSocketFrame frame = (WebSocketFrame) msg;
40 if (frame instanceof TextWebSocketFrame) {
41 // Text frame
42 ChannelBuffer data = frame.getBinaryData();
43 ChannelBuffer encoded = channel.getConfig().getBufferFactory()
44 .getBuffer(data.order(), data.readableBytes() + 2);
45 encoded.writeByte((byte) 0x00);
46 encoded.writeBytes(data, data.readerIndex(), data.readableBytes());
47 encoded.writeByte((byte) 0xFF);
48 return encoded;
49 } else if (frame instanceof CloseWebSocketFrame) {
50 // Close frame
51 ChannelBuffer data = frame.getBinaryData();
52 ChannelBuffer encoded = channel.getConfig().getBufferFactory().getBuffer(data.order(), 2);
53 encoded.writeByte((byte) 0xFF);
54 encoded.writeByte((byte) 0x00);
55 return encoded;
56 } else {
57 // Binary frame
58 ChannelBuffer data = frame.getBinaryData();
59 int dataLen = data.readableBytes();
60 ChannelBuffer encoded = channel.getConfig().getBufferFactory().getBuffer(data.order(), dataLen + 5);
61
62 // Encode type.
63 encoded.writeByte((byte) 0x80);
64
65 // Encode length.
66 int b1 = dataLen >>> 28 & 0x7F;
67 int b2 = dataLen >>> 14 & 0x7F;
68 int b3 = dataLen >>> 7 & 0x7F;
69 int b4 = dataLen & 0x7F;
70 if (b1 == 0) {
71 if (b2 == 0) {
72 if (b3 == 0) {
73 encoded.writeByte(b4);
74 } else {
75 encoded.writeByte(b3 | 0x80);
76 encoded.writeByte(b4);
77 }
78 } else {
79 encoded.writeByte(b2 | 0x80);
80 encoded.writeByte(b3 | 0x80);
81 encoded.writeByte(b4);
82 }
83 } else {
84 encoded.writeByte(b1 | 0x80);
85 encoded.writeByte(b2 | 0x80);
86 encoded.writeByte(b3 | 0x80);
87 encoded.writeByte(b4);
88 }
89
90 // Encode binary data.
91 encoded.writeBytes(data, data.readerIndex(), dataLen);
92 return encoded;
93 }
94 }
95 return msg;
96 }
97 }
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