netty4.0之TCP的server与client初探（与3.X版本变化）DEMO

痛定思痛。 2022-08-23 13:46 179阅读 0赞

1.新建服务端java工程

lib中放入:

log4j-1.2.17.jar

netty-all-4.0.19.Final.jar

slf4j-api-1.7.7.jar

slf4j-log4j12-1.7.7.jar

2.TcpServer.java

import io.netty.bootstrap.ServerBootstrap;  
import io.netty.channel.ChannelInitializer;  
import io.netty.channel.ChannelPipeline;  
import io.netty.channel.EventLoopGroup;  
import io.netty.channel.nio.NioEventLoopGroup;  
import io.netty.channel.socket.SocketChannel;  
import io.netty.channel.socket.nio.NioServerSocketChannel;  
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;  
import io.netty.handler.codec.LengthFieldPrepender;  
import io.netty.handler.codec.string.StringDecoder;  
import io.netty.handler.codec.string.StringEncoder;  
import io.netty.util.CharsetUtil;  
  
import org.apache.log4j.Logger;  
  
public class TcpServer \{  
    private static final Logger logger = Logger.getLogger(TcpServer.class);  
    private static final String IP = "127.0.0.1";  
    private static final int PORT = 9999;  
    /\*\* 用于分配处理业务线程的线程组个数 \*/  
    protected static final int BIZGROUPSIZE = Runtime.getRuntime()  
            .availableProcessors() \* 2; // 默认  
    /\*\* 业务出现线程大小 \*/  
    protected static final int BIZTHREADSIZE = 4;  
    private static final EventLoopGroup bossGroup = new NioEventLoopGroup(BIZGROUPSIZE);  
    private static final EventLoopGroup workerGroup = new NioEventLoopGroup(BIZTHREADSIZE);  
  
    protected static void run() throws Exception \{  
        ServerBootstrap b = new ServerBootstrap();  
        b.group(bossGroup, workerGroup);  
        b.channel(NioServerSocketChannel.class);  
        b.childHandler(new ChannelInitializer<SocketChannel>() \{  
            @Override  
            public void initChannel(SocketChannel ch) throws Exception \{  
                ChannelPipeline pipeline = ch.pipeline();  
                pipeline.addLast("frameDecoder",new LengthFieldBasedFrameDecoder(Integer.MAX\_VALUE, 0,4, 0, 4));  
                pipeline.addLast("frameEncoder", new LengthFieldPrepender(4));  
                pipeline.addLast("decoder",new StringDecoder(CharsetUtil.UTF\_8));  
                pipeline.addLast("encoder",new StringEncoder(CharsetUtil.UTF\_8));  
                pipeline.addLast(new TcpServerHandler());  
            \}  
        \});  
  
        b.bind(IP, PORT).sync();  
        logger.info("TCP服务器已启动");  
    \}  
  
    protected static void shutdown() \{  
        workerGroup.shutdownGracefully();  
        bossGroup.shutdownGracefully();  
    \}  
  
    public static void main(String\[\] args) throws Exception \{  
        logger.info("开始启动TCP服务器...");  
        TcpServer.run();  
        // TcpServer.shutdown();  
    \}  
\}

3.TcpServerHandler.java

import io.netty.channel.ChannelHandlerContext;  
import io.netty.channel.SimpleChannelInboundHandler;  
  
import org.apache.log4j.Logger;  
  
public class TcpServerHandler extends SimpleChannelInboundHandler<Object> \{  
  
    private static final Logger logger = Logger.getLogger(TcpServerHandler.class);  
  
    @Override  
    public void channelRead0(ChannelHandlerContext ctx, Object msg)  
            throws Exception \{  
        logger.info("SERVER接收到消息:" + msg);  
        ctx.channel().writeAndFlush("yes, server is accepted you ,nice !" + msg);  
    \}  
  
    @Override  
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)  
            throws Exception \{  
        logger.warn("Unexpected exception from downstream.", cause);  
        ctx.close();  
    \}  
\}

===============================

4.新建客户端java工程

lib中放入:

log4j-1.2.17.jar

netty-all-4.0.19.Final.jar

slf4j-api-1.7.7.jar

slf4j-log4j12-1.7.7.jar

5.TcpClient.java

import io.netty.bootstrap.Bootstrap;  
import io.netty.channel.Channel;  
import io.netty.channel.ChannelInitializer;  
import io.netty.channel.ChannelOption;  
import io.netty.channel.ChannelPipeline;  
import io.netty.channel.EventLoopGroup;  
import io.netty.channel.nio.NioEventLoopGroup;  
import io.netty.channel.socket.nio.NioSocketChannel;  
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;  
import io.netty.handler.codec.LengthFieldPrepender;  
import io.netty.handler.codec.string.StringDecoder;  
import io.netty.handler.codec.string.StringEncoder;  
import io.netty.util.CharsetUtil;  
  
import org.apache.log4j.Logger;  
  
public class TcpClient \{  
    private static final Logger logger = Logger.getLogger(TcpClient.class);  
    public static String HOST = "127.0.0.1";  
    public static int PORT = 9999;  
  
    public static Bootstrap bootstrap = getBootstrap();  
    public static Channel channel = getChannel(HOST, PORT);  
  
    /\*\*  
     \* 初始化Bootstrap  
     \*  
     \* @return  
     \*/  
    public static final Bootstrap getBootstrap() \{  
        EventLoopGroup group = new NioEventLoopGroup();  
        Bootstrap b = new Bootstrap();  
        b.group(group).channel(NioSocketChannel.class);  
        b.handler(new ChannelInitializer<Channel>() \{  
            @Override  
            protected void initChannel(Channel ch) throws Exception \{  
                ChannelPipeline pipeline = ch.pipeline();  
                pipeline.addLast("frameDecoder",new LengthFieldBasedFrameDecoder(Integer.MAX\_VALUE, 0,4, 0, 4));  
                pipeline.addLast("frameEncoder", new LengthFieldPrepender(4));  
                pipeline.addLast("decoder",new StringDecoder(CharsetUtil.UTF\_8));  
                pipeline.addLast("encoder",new StringEncoder(CharsetUtil.UTF\_8));  
                pipeline.addLast("handler", new TcpClientHandler());  
            \}  
        \});  
        b.option(ChannelOption.SO\_KEEPALIVE, true);  
        return b;  
    \}  
  
    public static final Channel getChannel(String host, int port) \{  
        Channel channel = null;  
        try \{  
            channel = bootstrap.connect(host, port).sync().channel();  
        \} catch (Exception e) \{  
            logger.error(  
                    String.format("连接Server(IP\[%s\],PORT\[%s\])失败", host, port), e);  
            return null;  
        \}  
        return channel;  
    \}  
  
    public static void sendMsg(String msg) throws Exception \{  
        if (channel != null) \{  
            channel.writeAndFlush(msg).sync();  
        \} else \{  
            logger.warn("消息发送失败,连接尚未建立!");  
        \}  
    \}  
  
    public static void main(String\[\] args) throws Exception \{  
        try \{  
            long t0 = System.nanoTime();  
            for (int i = 0; i < 1000; i++) \{  
                TcpClient.sendMsg(i + "你好1");  
            \}  
            long t1 = System.nanoTime();  
            System.out.println((t1 - t0) / 1000000.0);  
        \} catch (Exception e) \{  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
        \}  
    \}  
\}

6.TcpClientHandler.java

import org.apache.log4j.Logger;  
  
import io.netty.channel.ChannelHandlerContext;  
import io.netty.channel.SimpleChannelInboundHandler;  
  
public class TcpClientHandler extends SimpleChannelInboundHandler<Object> \{  
    private static final Logger logger = Logger.getLogger(TcpClientHandler.class);  
  
    @Override  
    protected void channelRead0(ChannelHandlerContext ctx, Object msg)  
            throws Exception \{  
        // messageReceived方法,名称很别扭，像是一个内部方法.  
        logger.info("client接收到服务器返回的消息:" + msg);  
  
    \}  
  
\}

转自:http://blog.163.com/linfenliang@126/blog/static/12785719520137159347646/