java-使用netty实现客户端向服务端存储数据的简单实现

可以使用write:1，实现想服务端存储1的数据，使用read命令可以读取刚才的写入的数据，效果如下
服务端

read
read is inputs
请输入消息：
客户端读取服务返回的数据：1
客户端读取服务返回的数据：服务端已经读取消息完成!read
write:999
write:999 is inputs
请输入消息：
客户端读取服务返回的数据：服务端已经读取消息完成!write:999
read
read is inputs
请输入消息：
客户端读取服务返回的数据：999
客户端读取服务返回的数据：服务端已经读取消息完成!read
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package sample.netty.newtest;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.util.CharsetUtil;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;

public class nettyServerTest {

    private int port;

    public nettyServerTest(int port) {
        this.port = port;
    }

    public void run() throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup(); // (1)
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap(); // (2)
            b.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class) // (3)
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel channel) throws Exception {
                            channel.pipeline().addLast(new LineBasedFrameDecoder(1024));
                            channel.pipeline().addLast(new StringDecoder());
                            channel.pipeline().addLast(new NettyServerHandler());
                        }
                    })
                    .option(ChannelOption.SO_BACKLOG, 128)          // (5)
                    .childOption(ChannelOption.SO_KEEPALIVE, true); // (6)

            // Bind and start to accept incoming connections.
            ChannelFuture f = b.bind(port).sync(); // (7)

            // Wait until the server socket is closed.
            // In this example, this does not happen, but you can do that to gracefully
            // shut down your server.
            f.channel().closeFuture().sync();
        } finally {
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();
        }
    }

    public class NettyServerHandler extends ChannelInboundHandlerAdapter { // (1)
        int currentValue=0;
        String pubMSG;
        @Override
        public void channelRead(ChannelHandlerContext ctx, Object msg) throws IOException { // (2)
            String byteBuf = (String) msg;
            pubMSG=byteBuf;
            System.out.println("客户端发来的消息是：" + byteBuf);

            if(byteBuf.contains("write:")){
                currentValue=Integer.parseInt(byteBuf.split(":")[1]);
            }
            if(byteBuf.contains("read")){
                ctx.writeAndFlush(Unpooled.copiedBuffer(currentValue+"\r\n", CharsetUtil.UTF_8));
            }
        }

        //数据读取完毕事件
        public void channelReadComplete(ChannelHandlerContext ctx) throws IOException, InterruptedException {
            //数据读取完毕，将信息包装成一个Buffer传递给下一个Handler，Unpooled.copiedBuffer会返回一个Buffer
            //调用的是事件处理器的上下文对象的writeAndFlush方法
            //意思就是说将  你好  传递给了下一个handler
            ctx.writeAndFlush(Unpooled.copiedBuffer("服务端已经读取消息完成!"+pubMSG+"\r\n", CharsetUtil.UTF_8));
        }

        @Override
        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { // (4)
            // Close the connection when an exception is raised.
            cause.printStackTrace();
            ctx.close();
        }
    }

    public static void main(String[] args) throws Exception {
        int port = 1003;
//        if (args.length > 0) {
//            port = Integer.parseInt(args[0]);
//        }
        new nettyServerTest(port).run();
    }
}
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客户端
package sample.netty.newtest;

import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.util.CharsetUtil;

import java.io.IOException;
import java.util.Scanner;

public class nettyClient {
ChannelHandlerContext ctxOut;
public static void main(String[] args) throws Exception {
NettyClientHandlerInner nettyClientHandlerInner=new NettyClientHandlerInner();

    new Thread(new Runnable() {
        @Override
        public void run() {
            while (true){
                Scanner scanner=new Scanner(System.in);
                System.out.println("请输入消息：");
                String inputs=scanner.nextLine();
                System.out.println(inputs+" is inputs");
                nettyClientHandlerInner.sendMSG(inputs);
            }
        }
    }).start();

    connectToServer(nettyClientHandlerInner);
    System.out.println(222222);
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// while (true){
// Scanner scanner=new Scanner(System.in);
// String inputs=scanner.nextLine();
// nettyClientHandlerInner.ctxOut.writeAndFlush(Unpooled.copiedBuffer(inputs+“\r\n”, CharsetUtil.UTF_8));;
// }

}

public static void connectToServer(NettyClientHandlerInner nettyClientHandler){
    EventLoopGroup workerGroup = new NioEventLoopGroup();

    try {
        Bootstrap b = new Bootstrap(); // (1)
        b.group(workerGroup); // (2)
        b.channel(NioSocketChannel.class); // (3)
        b.option(ChannelOption.SO_KEEPALIVE, true); // (4)
        b.handler(new ChannelInitializer() {
            @Override
            public void initChannel(SocketChannel ch) throws Exception {
                ch.pipeline().addLast(new LineBasedFrameDecoder(1024));
                ch.pipeline().addLast(new StringDecoder());
                ch.pipeline().addLast(nettyClientHandler);
            }
        });

        // Start the client.
        ChannelFuture f = b.connect("127.0.0.1", 1003).sync(); // (5)

        // Wait until the connection is closed.
        f.channel().closeFuture().sync();
    } catch (InterruptedException e) {
        e.printStackTrace();
    } finally {
        workerGroup.shutdownGracefully();
    }
}
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}

//客户端业务处理类
class NettyClientHandlerInner extends ChannelInboundHandlerAdapter {
ChannelHandlerContext ctxOut;
//通道就绪事件(就是在bootstrap启动助手配置中addlast了handler之后就会触发此事件)
//但我觉得也可能是当有客户端连接上后才为一次通道就绪
public void channelActive(ChannelHandlerContext ctx) throws IOException, InterruptedException {
System.out.println(“客户端消息，通道激活，可以发送消息了”);
ctxOut=ctx;
}

//数据读取事件
public void channelRead(ChannelHandlerContext ctx, Object msg) {
    //传来的消息包装成字节缓冲区
    String byteBuf = (String) msg;
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// ByteBuf byteBuf = (ByteBuf) msg;
//Netty提供了字节缓冲区的toString方法，并且可以设置参数为编码格式：CharsetUtil.UTF_8
System.out.println(“客户端读取服务返回的数据：” + byteBuf);
}

public void  sendMSG(String msg){
    ctxOut.writeAndFlush(Unpooled.copiedBuffer(msg+"\r\n", CharsetUtil.UTF_8));
}
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}