netty 服务端客户端-实例

效果图

Server端代码

package cn.itcast.netty.basic;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;

//服务器端的业务处理类
public class NettyServerHandler extends ChannelInboundHandlerAdapter {

    //读取数据事件
    public void channelRead(ChannelHandlerContext ctx,Object msg){
        System.out.println("Server:"+ctx);
        ByteBuf buf=(ByteBuf) msg;
        System.out.println("客户端发来的消息："+buf.toString(CharsetUtil.UTF_8));
    }

    //数据读取完毕事件
    public void channelReadComplete(ChannelHandlerContext ctx){
        ctx.writeAndFlush(Unpooled.copiedBuffer("就是没钱",CharsetUtil.UTF_8));
    }

    //异常发生事件
    public void exceptionCaught(ChannelHandlerContext ctx,Throwable t){
        ctx.close();
    }


}

package cn.itcast.netty.basic;

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

public class NettyServer {
    public static void main(String[] args) throws Exception{

        //1. 创建一个线程组：接收客户端连接
        EventLoopGroup bossGroup =new NioEventLoopGroup();
        //2. 创建一个线程组：处理网络操作
        EventLoopGroup workerGroup =new NioEventLoopGroup();
        //3. 创建服务器端启动助手来配置参数
        ServerBootstrap b=new ServerBootstrap();
        b.group(bossGroup,workerGroup) //4.设置两个线程组
         .channel(NioServerSocketChannel.class) //5.使用NioServerSocketChannel作为服务器端通道的实现
         .option(ChannelOption.SO_BACKLOG,128) //6.设置线程队列中等待连接的个数
         .childOption(ChannelOption.SO_KEEPALIVE,true) //7.保持活动连接状态
         .childHandler(new ChannelInitializer<SocketChannel>() {  //8. 创建一个通道初始化对象
             public void initChannel(SocketChannel sc){   //9. 往Pipeline链中添加自定义的handler类
                 sc.pipeline().addLast(new NettyServerHandler());
             }
         });
        System.out.println("......Server is ready......");
        ChannelFuture cf=b.bind(9999).sync();  //10. 绑定端口 bind方法是异步的  sync方法是同步阻塞的
        System.out.println("......Server is starting......");

        //11. 关闭通道，关闭线程组
        cf.channel().closeFuture().sync(); //异步
        bossGroup.shutdownGracefully();
        workerGroup.shutdownGracefully();
    }
}

客户端代码

package cn.itcast.netty.basic;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;

//客户端业务处理类
public class NettyClientHandler extends ChannelInboundHandlerAdapter {

    //通道就绪事件
    public void channelActive(ChannelHandlerContext ctx){
        System.out.println("Client:"+ctx);
        ctx.writeAndFlush(Unpooled.copiedBuffer("老板，还钱吧",CharsetUtil.UTF_8));
    }

    //读取数据事件
    public void channelRead(ChannelHandlerContext ctx,Object msg){
        ByteBuf buf=(ByteBuf) msg;
        System.out.println("服务器端发来的消息："+buf.toString(CharsetUtil.UTF_8));
    }

}

package cn.itcast.netty.basic;

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

//网络客户端
public class NettyClient {
    public static void main(String[] args) throws  Exception{

        //1. 创建一个线程组
        EventLoopGroup group=new NioEventLoopGroup();
        //2. 创建客户端的启动助手，完成相关配置
        Bootstrap b=new Bootstrap();
        b.group(group)  //3. 设置线程组
         .channel(NioSocketChannel.class)  //4. 设置客户端通道的实现类
         .handler(new ChannelInitializer<SocketChannel>() {  //5. 创建一个通道初始化对象
             @Override
             protected void initChannel(SocketChannel socketChannel) throws Exception {
                 socketChannel.pipeline().addLast(new NettyClientHandler()); //6.往Pipeline链中添加自定义的handler
             }
         });
        System.out.println("......Client is  ready......");

        //7.启动客户端去连接服务器端  connect方法是异步的   sync方法是同步阻塞的
        ChannelFuture cf=b.connect("127.0.0.1",9999).sync();

        //8.关闭连接(异步非阻塞)
        cf.channel().closeFuture().sync();

    }
}