Netty的第一个例子

import io.netty.bootstrap.ServerBootstrap;

import io.netty.channel.ChannelFuture;
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;


public class TimeServer {

    public void bind(int port) throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();

        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workerGroup)
                           .channel(NioServerSocketChannel.class)
                           .option(ChannelOption.SO_BACKLOG, 1024)
                           .childHandler(new ChildChannelHandler());
            //绑定端口，同步等待成功
            ChannelFuture future = serverBootstrap.bind(port).sync();
            //等待服务端监听端口关闭
            future.channel().closeFuture().sync();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            //优雅退出
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

    private class ChildChannelHandler extends ChannelInitializer<SocketChannel> {
        @Override
        protected void initChannel(SocketChannel socketChannel) throws Exception {
            socketChannel.pipeline().addLast(new TimeServerHandler());
        }
    }

    public static void main(String[] args) throws Exception {
        int port = 8080;
        if (args != null && args.length > 0) {
            try {
                port = Integer.parseInt(args[0]);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        new TimeServer().bind(port);
    }

}

TimeServerHandler

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import java.sql.Timestamp;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

public class TimeServerHandler extends ChannelInboundHandlerAdapter {

    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        ByteBuf buf = (ByteBuf) msg;
        byte[] req = new byte[buf.readableBytes()];
        buf.readBytes(req);
        String body = new String(req, "UTF-8");
        System.out.println("The time server receive order:" + body);

        String currentTime = "QUERY TIME ORDER".equalsIgnoreCase(body) ? new Date(System.currentTimeMillis()).toString() : "BAD ORDER";

        ByteBuf resp = Unpooled.copiedBuffer(currentTime.getBytes());
        ctx.write(resp);
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        super.exceptionCaught(ctx, cause);
    }
}

TimeClient

import io.netty.bootstrap.Bootstrap; import io.netty.channel.ChannelFuture; 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.NioSocketChannel; public class TimeClient { public void connect(int port, String host) throws Exception { //配置客户端NIO线程组 EventLoopGroup eventLoopGroup = new NioEventLoopGroup(); try { Bootstrap bootstrap = new Bootstrap(); bootstrap.group(eventLoopGroup) .channel(NioSocketChannel.class) .option(ChannelOption.SO_BACKLOG, 1024) .handler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel socketChannel) throws Exception { socketChannel.pipeline().addLast(new TimeClientHandler()); } }); //发起异步链接操作 ChannelFuture channelFuture = bootstrap.connect(host, port).sync(); //等待客户端链路关闭 channelFuture.channel().closeFuture().sync(); } catch (Exception e) { e.printStackTrace(); } finally { //优雅退出，释放NIO线程组 eventLoopGroup.shutdownGracefully(); } } public static void main(String[] args) throws Exception { int port = 8080; if (args != null && args.length > 0) { try { port = Integer.parseInt(args[0]); } catch (Exception e) { //采用默认值 e.printStackTrace(); } } new TimeClient().connect(port, "127.0.0.1"); }

TimeClientHandler

Time

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

public class TimeClientHandler extends ChannelInboundHandlerAdapter {

    private ByteBuf firstMessage;

    public TimeClientHandler() {
        byte[] req = "QUERY TIME ORDER".getBytes();
        this.firstMessage = Unpooled.buffer(req.length);
        this.firstMessage.writeBytes(req);
    }

    public void channelActive(ChannelHandlerContext ctx) {
        ctx.writeAndFlush(this.firstMessage);
    }

    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        ByteBuf byteBuf = (ByteBuf)msg;
        byte[] req = new byte[byteBuf.readableBytes()];
        byteBuf.readBytes(req);
        String body = new String(req, "UTF-8");
        System.out.println("Now is " + body);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        super.exceptionCaught(ctx, cause);
    }
}

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