netty socket 客服端编程

package com.ming.netty.nio;

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;

/**
 * netty 客户端模拟
 * @author mingge
 *
 */
public class TimeClient {
    
    
    public static void main(String[] args) throws Exception{
        new TimeClient().connect("127.0.0.1", 8400);
    }

    public void connect(String addr,int port) throws Exception{
        EventLoopGroup group=new NioEventLoopGroup();
        try {
            Bootstrap b=new Bootstrap();
            b.group(group).channel(NioSocketChannel.class)
            .option(ChannelOption.TCP_NODELAY, true)
            .handler(new ChannelInitializer<SocketChannel>() {
                public void initChannel(SocketChannel ch) throws Exception{
                    ch.pipeline().addLast(new TimeClientHandler());
                }
            });
            ChannelFuture f=b.connect(addr,port);
            f.channel().closeFuture().sync();//等待客户端关闭连接
        } catch (Exception e) {
            // TODO: handle exception
        }finally{
            group.shutdownGracefully();
        }
    }
}

package com.ming.netty.nio;

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

public class TimeClientHandler extends ChannelHandlerAdapter {
    
    private final ByteBuf byteMsg;
    
    public TimeClientHandler() {
        byte[] req="我是请求数据哦".getBytes();
        byteMsg=Unpooled.buffer(req.length);
        byteMsg.writeBytes(req);
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        ctx.writeAndFlush(byteMsg);
    }

    @Override
    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,"GBK");
        System.out.println("body:"+body);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        //释放资源
        ctx.close();
    }

    
}