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 * https://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.example.echo;
17
18 import io.netty.buffer.ByteBuf;
19 import io.netty.buffer.Unpooled;
20 import io.netty.channel.ChannelHandlerContext;
21 import io.netty.channel.ChannelInboundHandlerAdapter;
22
23 /**
24 * Handler implementation for the echo client. It initiates the ping-pong
25 * traffic between the echo client and server by sending the first message to
26 * the server.
27 */
28 public class EchoClientHandler extends ChannelInboundHandlerAdapter {
29
30 private final ByteBuf firstMessage;
31
32 /**
33 * Creates a client-side handler.
34 */
35 public EchoClientHandler() {
36 firstMessage = Unpooled.buffer(EchoClient.SIZE);
37 for (int i = 0; i < firstMessage.capacity(); i ++) {
38 firstMessage.writeByte((byte) i);
39 }
40 }
41
42 @Override
43 public void channelActive(ChannelHandlerContext ctx) {
44 ctx.writeAndFlush(firstMessage);
45 }
46
47 @Override
48 public void channelRead(ChannelHandlerContext ctx, Object msg) {
49 ctx.write(msg);
50 }
51
52 @Override
53 public void channelReadComplete(ChannelHandlerContext ctx) {
54 ctx.flush();
55 }
56
57 @Override
58 public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
59 // Close the connection when an exception is raised.
60 cause.printStackTrace();
61 ctx.close();
62 }
63 }