netty4.0.23 简单demo

 

例子共4个文件，用到的jar包有：

netty-all-4.0.23.Final.jar

log4j.jar （apache的）

commons-logging-1.1.1.jar（apache的）

 

文件 TcpServerHandler

 

package test.netty;

import org.apache.log4j.Logger;

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

public class TcpServerHandler extends SimpleChannelInboundHandler<Object> {

    private static final Logger logger = Logger.getLogger(TcpServerHandler.class);

    @Override
    protected 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();
    }

}

 

 

文件 TcpServer

package test.netty;

import org.apache.log4j.Logger;

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;

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;
        /*
     * NioEventLoopGroup实际上就是个线程池,
     * NioEventLoopGroup在后台启动了n个NioEventLoop来处理Channel事件,
     * 每一个NioEventLoop负责处理m个Channel,
     * NioEventLoopGroup从NioEventLoop数组里挨个取出NioEventLoop来处理Channel
     */
    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();
    }
}

 

文件 TcpClientHandler

package test.netty;

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);

    }

}

 

文件 TcpClient

package test.netty;

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 < 100000; i++) {
                TcpClient.sendMsg(i+"你好1");
            }
            long t1 = System.nanoTime();
            System.out.println((t1-t0)/1000000.0);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}