需求：服务端接收客户端发送的数据，并将数据返回给客户端
- 客户端代码
public final class EchoClient {
public static void main(String[] args) {
try {
NioEventLoopGroup group = new NioEventLoopGroup();
Channel channel = new Bootstrap()
.group(group)
.channel(NioSocketChannel.class)
.handler(new ChannelInitializer<NioSocketChannel>() {
@Override
protected void initChannel(NioSocketChannel ch) throws Exception {
//添加handler
ChannelPipeline p = ch.pipeline();
p.addLast(new LoggingHandler(LogLevel.DEBUG));
ch.pipeline().addLast(new StringEncoder()); //bytebuf转为字符串
ch.pipeline().addLast(new StringDecoder()); //bytebuf转为字符串
ch.pipeline().addLast(new EchoClientHandler()); //bytebuf转为字符串
}
}).connect(new InetSocketAddress("localhost", 8007))
.sync()
.channel();
new Thread(() -> {
Scanner scanner = new Scanner(System.in);
while (true) {
String line = scanner.nextLine();
if ("q".equals(line)) {
channel.close();
// log.debug("处理关闭之后操作");
break;
}
channel.writeAndFlush(line);
}
}, "input_client").start();
// 方法①获取closeFuture对象
/* ChannelFuture closeFuture = channel.closeFuture();
log.debug("waiting close");
closeFuture.sync();
log.debug("处理关闭之后操作");*/
ChannelFuture closeFuture = channel.closeFuture();
closeFuture.addListener((ChannelFutureListener) future -> {
group.shutdownGracefully();//线程组停下来
});
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
- 客户端handler
/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.example.echo;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import java.nio.charset.Charset;
/**
* Handler implementation for the echo client. It initiates the ping-pong
* traffic between the echo client and server by sending the first message to
* the server.
*/
public class EchoClientHandler extends ChannelInboundHandlerAdapter {
private ByteBuf firstMessage;
/**
* Creates a client-side handler.
*/
public EchoClientHandler() {
/* firstMessage = Unpooled.buffer(EchoClient.SIZE);
for (int i = 0; i < firstMessage.capacity(); i ++) {
firstMessage.writeByte((byte) i);
}*/
}
@Override
public void channelActive(ChannelHandlerContext ctx) {
// ctx.writeAndFlush(firstMessage);
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) {
System.out.println("接受服务器的消息："+msg);
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) {
ctx.flush();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
// Close the connection when an exception is raised.
cause.printStackTrace();
ctx.close();
}
}
- 服务端代码
public final class EchoServer {
static final boolean SSL = System.getProperty("ssl") != null;
static final int PORT = Integer.parseInt(System.getProperty("port", "8007"));
public static void main(String[] args) throws Exception {
// Configure SSL.
final SslContext sslCtx;
if (SSL) {
SelfSignedCertificate ssc = new SelfSignedCertificate();
sslCtx = SslContextBuilder.forServer(ssc.certificate(), ssc.privateKey()).build();
} else {
sslCtx = null;
}
// Configure the server.
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup();
final EchoServerHandler serverHandler = new EchoServerHandler();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.option(ChannelOption.SO_BACKLOG, 100)
.handler(new LoggingHandler(LogLevel.INFO))
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
public void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
p.addLast(new LoggingHandler(LogLevel.DEBUG));
if (sslCtx != null) {
p.addLast(sslCtx.newHandler(ch.alloc()));
}
p.addLast(new StringEncoder()); //bytebuf转为字符串
p.addLast(new StringDecoder()); //bytebuf转为字符串
p.addLast(serverHandler);
}
});
// Start the server.
ChannelFuture f = b.bind(PORT).sync();
// Wait until the server socket is closed.
f.channel().closeFuture().sync();
} finally {
// Shut down all event loops to terminate all threads.
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
- 服务端handler
@Sharable
public class EchoServerHandler extends ChannelInboundHandlerAdapter {
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) {
// ctx.write(msg);
System.out.println("接受客户端的消息：" + msg);
ctx.writeAndFlush(msg.toString().toUpperCase());
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) {
ctx.flush();
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
// Close the connection when an exception is raised.
cause.printStackTrace();
ctx.close();
}
}
客户端
服务端
