Netty的簡單應用

Netty客戶端

package com.example.demo.netty;

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;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;

public class TimeNettyClient {
    public static void main(String[] args) throws Exception {
        String host = "localhost";
        int port = 8080;
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap(); // (1)
            b.group(workerGroup); // (2)
            b.channel(NioSocketChannel.class); // (3)
            b.handler(new ChannelInitializer<SocketChannel>() {// (4)
                @Override
                public void initChannel(SocketChannel ch) throws Exception {
                    ch.pipeline().addLast(new LineBasedFrameDecoder(1024));
                    ch.pipeline().addLast(new StringDecoder());
                    ch.pipeline().addLast(new TimeClientHandler());
                }
            });
            // Start the client.
            ChannelFuture f = b.connect(host, port).sync(); // (5)
            // Wait until the connection is closed.
            f.channel().closeFuture().sync();
        } finally {
            workerGroup.shutdownGracefully();
        }
    }
}

客戶端通道處理器

package com.example.demo.netty;

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

public class TimeClientHandler extends ChannelInboundHandlerAdapter {
    private byte[] req=("QUERY TIME ORDER" + System.getProperty("line.separator")).getBytes();
    @Override
    public void channelActive(ChannelHandlerContext ctx) {//1
        ByteBuf message = Unpooled.buffer(req.length);
        message.writeBytes(req);
        ctx.writeAndFlush(message);
    }
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        String body = (String) msg;
        System.out.println("Now is:" + body);
    }
}

Netty服務端

package com.example.demo.netty;

import io.netty.bootstrap.ServerBootstrap;
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.NioServerSocketChannel;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;

public class TimeNettyServer {
	
    private int port=8080;
    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>() { // (4)
                        @Override
                        public void initChannel(SocketChannel ch) throws Exception {
                            ch.pipeline().addLast(new LineBasedFrameDecoder(1024));
                            ch.pipeline().addLast(new StringDecoder());
                            ch.pipeline().addLast(new TimeServerHandler());
                        }
                    });
           
            ChannelFuture f = b.bind(port).sync(); // (5)
            System.out.println("TimeServer Started on 8080...");
            f.channel().closeFuture().sync();
        } finally {
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();
        }
    }
    public static void main(String[] args) throws Exception {
        new TimeNettyServer().run();
    }
}

服務端通道處理器

package com.example.demo.netty;

import java.util.Date;

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

public class TimeServerHandler extends ChannelInboundHandlerAdapter {
   @Override
   public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { // 1
      String request = (String) msg; //2
      String response = null;
      if ("QUERY TIME ORDER".equals(request)) { // 3
         response = new Date(System.currentTimeMillis()).toString();
      } else {
         response = "BAD REQUEST";
      }
      response = response + System.getProperty("line.separator"); // 4
      ByteBuf resp = Unpooled.copiedBuffer(response.getBytes()); // 5
      ctx.writeAndFlush(resp); // 6
   }
}

程序測試

package com.example.demo.netty;

import java.net.InetSocketAddress;
import java.net.SocketAddress;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelDuplexHandler;
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;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.util.AttributeKey;

public class NettyTest {
	
	public static void main(String[] args) {
		
		SocketAddress localAddress = new InetSocketAddress(8800);
		
		EventLoopGroup bossGroup = new NioEventLoopGroup(1);
		EventLoopGroup workerGroup = new NioEventLoopGroup(3);
		ServerBootstrap server = new ServerBootstrap(); 
		server.group(bossGroup, workerGroup)
	          .channel(NioServerSocketChannel.class)
	          .handler(new LoggingHandler(LogLevel.INFO))
	          .option(ChannelOption.SO_BACKLOG, 128)
	          .attr(AttributeKey.valueOf("ssc.key"),"scc.value")
	          .childHandler(new ChannelInitializer<SocketChannel>() {
	            @Override
	            public void initChannel(SocketChannel ch) throws Exception {
	                ch.pipeline().addLast(new ChannelDuplexHandler());
	              }
	          }) 
	          .childOption(ChannelOption.SO_KEEPALIVE, true); 
		
		server.bind(localAddress);
	}

}