# 聊天室

## 客户端

```java
package demo3;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;

import java.io.BufferedReader;
import java.io.InputStreamReader;

/**
 * @Author: small_double
 * @Date: 2019/10/8 下午6:20
 */
public class TestClient {
    public static void main(String[] args) {
        EventLoopGroup bossGroup=new NioEventLoopGroup();
        try {
            Bootstrap bootstrap=new Bootstrap();
            bootstrap.group(bossGroup)
                    .channel(NioSocketChannel.class)
                    .handler(new TestClientInitializer());

            ChannelFuture channelFuture = bootstrap.connect("127.0.0.1",8989).sync();
            Channel channel = channelFuture.channel();

            BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(System.in));
            for(; ;){
                channel.writeAndFlush( bufferedReader.readLine()+"\r\n");
                // System.out.println(s);
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            bossGroup.shutdownGracefully();
        }
    }
}
```

## 客户端handler

```java
package demo3;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

/**
 * @Author: small_double
 * @Date: 2019/10/8 下午6:31
 */

public class TestClientHandler extends SimpleChannelInboundHandler<String> {
    @Override
    protected void channelRead0(ChannelHandlerContext channelHandlerContext, String s) throws Exception {
        System.out.println(s.trim()+"\n");
    }


    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
}
```

## 客户端initializer

```java
package demo3;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.DelimiterBasedFrameDecoder;
import io.netty.handler.codec.Delimiters;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.util.CharsetUtil;

/**
 * @Author: small_double
 * @Date: 2019/10/8 下午6:28
 */
public class TestClientInitializer extends ChannelInitializer<SocketChannel> {

    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {
        ChannelPipeline pipeline = socketChannel.pipeline();
        // 换行符handler
        pipeline.addLast(new DelimiterBasedFrameDecoder(4096, Delimiters.lineDelimiter()));//基于分隔符的解码器
        pipeline.addLast(new StringDecoder(CharsetUtil.UTF_8));
        pipeline.addLast(new StringEncoder(CharsetUtil.UTF_8));
        pipeline.addLast(new TestClientHandler());
    }
}
```

## 服务端

```java
package demo3;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;

/**
 * @Author: small_double
 * @Date: 2019/10/8 下午5:50
 */
public class TestServe {
    public static void main(String[] args) {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new TestServerInitializer());
            ChannelFuture channelFuture = serverBootstrap.bind(8989).sync();
            channelFuture.channel().closeFuture().sync();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }
    }
}
```

## 服务端handler

```java
package demo3;

import io.netty.channel.Channel;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.util.concurrent.EventExecutor;
import io.netty.util.concurrent.EventExecutorGroup;
import io.netty.util.concurrent.GlobalEventExecutor;

/**
 * @Author: small_double
 * @Date: 2019/10/8 下午6:06
 */
public class TestServerHandler extends SimpleChannelInboundHandler<String> {

    private static ChannelGroup group = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);

    @Override
    public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
        Channel channel = ctx.channel();
        group.writeAndFlush(channel.remoteAddress() + "加入\n");
        group.add(channel);

    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        Channel channel = ctx.channel();
        System.out.println(channel.remoteAddress() + "上线\n");
        System.out.println(group.size());
    }


    @Override
    public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
        Channel channel = ctx.channel();
        System.out.println(channel.remoteAddress() + "离开\n");
        System.out.println(group.size());
    }

    //channel不活跃  通道关闭事件
    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        Channel channel = ctx.channel();
        System.out.println(channel.remoteAddress() + "下线\n");
    }

    //channel注册事件
    @Override
    public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
        System.out.println("channelRegistered");
        super.channelRegistered(ctx);
    }

    protected void channelRead0(ChannelHandlerContext channelHandlerContext, String s) throws Exception {
        final Channel channel = channelHandlerContext.channel();
        group.forEach(ch -> {
            if (channel != ch) {
                ch.writeAndFlush(channel.remoteAddress() + ":" + s + "\r\n");
            }
        });
        channelHandlerContext.fireChannelRead(s);
    }
}
```

## 服务端initializer

```java
package demo3;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.DelimiterBasedFrameDecoder;
import io.netty.handler.codec.Delimiters;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.util.CharsetUtil;

/**
 * @Author: small_double
 * @Date: 2019/10/8 下午5:52
 */
public class TestServerInitializer extends ChannelInitializer<SocketChannel> {

    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {
        ChannelPipeline channelPipeline = socketChannel.pipeline();
        channelPipeline.addLast(new DelimiterBasedFrameDecoder(4096, Delimiters.lineDelimiter()));
        channelPipeline.addLast(new StringDecoder(CharsetUtil.UTF_8));
        channelPipeline.addLast(new StringEncoder(CharsetUtil.UTF_8));
        channelPipeline.addLast(new TestServerHandler());

    }
}
```


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