netty4.0.23 初学的demo

 

 

netty4.0.23 初学的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();
		}
    }
}

 

 

 

 

 

评论

3 楼 heng123 2017-10-03  

Netty视频教程https://www.douban.com/note/619228582/

2 楼 maotou1988 2017-05-08  

使用Netty进行Android与Server端通信实现文字发送接收与图片上传
https://lison.cc/508.html

1 楼 reaganzuoluo 2016-08-03  

例子  有点注释就好了。。。