基于Netty的RPC架构学习笔记（三）：netty客户端

举个🌰

Client.java

package com.client;

import java.net.InetSocketAddress;
import java.util.Scanner;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import org.jboss.netty.bootstrap.ClientBootstrap;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory;
import org.jboss.netty.handler.codec.string.StringDecoder;
import org.jboss.netty.handler.codec.string.StringEncoder;
/**

- netty客户端入门

- =
  *
   */
  public class Client {

  public static void main(String[] args) {
  	


  //服务类
  ClientBootstrap bootstrap = new  ClientBootstrap();
  
  //线程池
  ExecutorService boss = Executors.newCachedThreadPool();
  ExecutorService worker = Executors.newCachedThreadPool();
  
  //socket工厂
  bootstrap.setFactory(new NioClientSocketChannelFactory(boss, worker));
  
  //管道工厂
  bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
  	
  	@Override
  	public ChannelPipeline getPipeline() throws Exception {
  		ChannelPipeline pipeline = Channels.pipeline();
  		pipeline.addLast("decoder", new StringDecoder());
  		pipeline.addLast("encoder", new StringEncoder());
  		pipeline.addLast("hiHandler", new HiHandler());
  		return pipeline;
  	}
  });
  
  //连接服务端
  ChannelFuture connect = bootstrap.connect(new InetSocketAddress("127.0.0.1", 10101));
  Channel channel = connect.getChannel();
  
  System.out.println("client start");
  
  Scanner scanner = new Scanner(System.in);
  while(true){
  	System.out.println("请输入");
  	channel.write(scanner.next());
  }


  }

}

HiHandler.java

package com.client;

import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelHandler;
/**

- 消息接受处理类

- =
  *
   */
  public class HiHandler extends SimpleChannelHandler {

  /**

  - 接收消息
    */
    @Override
    public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) throws Exception {

    String s = (String) e.getMessage();
    System.out.println(s);

    super.messageReceived(ctx, e);
    }

  /**

  - 捕获异常
    */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) throws Exception {
    System.out.println("exceptionCaught");
    super.exceptionCaught(ctx, e);
    }

  /**

  - 新连接
    */
    @Override
    public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
    System.out.println("channelConnected");
    super.channelConnected(ctx, e);
    }

  /**

  - 必须是链接已经建立，关闭通道的时候才会触发
    */
    @Override
    public void channelDisconnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
    System.out.println("channelDisconnected");
    super.channelDisconnected(ctx, e);
    }

  /**

  - channel关闭的时候触发
    */
    @Override
    public void channelClosed(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
    System.out.println("channelClosed");
    super.channelClosed(ctx, e);
    }
    }

channelDisconnected与channelClosed的区别？
channelDisconnected只有在连接建立后断开才会调用
channelClosed无论连接是否成功都会调用关闭资源
在这里验证下：
当server没有开启的时候，client去请求，发现报错，然后只打印了channelClosed，而没有打印channelConnected
server开启并client和server正常交互后将服务端断开会打印channelDisconnected