基於Netty的RPC架構實戰演練（四）-netty5服務端和客戶端

一，netty5服務端入門案例

package com.server;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
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.nio.NioServerSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

/**
 * netty5服務端
 *
 */
public class Server {

	public static void main(String[] args) {
		//服務類
		ServerBootstrap bootstrap = new ServerBootstrap();
		
		//boss和worker
		EventLoopGroup boss = new NioEventLoopGroup();
		EventLoopGroup worker = new NioEventLoopGroup();
		
		try {
			//設置線程池
			bootstrap.group(boss, worker);
			
			//設置socket工廠、
			bootstrap.channel(NioServerSocketChannel.class);
			
			//設置管道工廠
			bootstrap.childHandler(new ChannelInitializer<Channel>() {

				@Override
				protected void initChannel(Channel ch) throws Exception {
					ch.pipeline().addLast(new StringDecoder());
					ch.pipeline().addLast(new StringEncoder());
					ch.pipeline().addLast(new ServerHandler());
				}
			});
			
			//netty3中對應設置如下
			//bootstrap.setOption("backlog", 1024);
			//bootstrap.setOption("tcpNoDelay", true);
			//bootstrap.setOption("keepAlive", true);
			//設置參數，TCP參數
			bootstrap.option(ChannelOption.SO_BACKLOG, 2048);//serverSocketchannel的設置，鏈接緩衝池的大小
			bootstrap.childOption(ChannelOption.SO_KEEPALIVE, true);//socketchannel的設置,維持鏈接的活躍，清除死鏈接
			bootstrap.childOption(ChannelOption.TCP_NODELAY, true);//socketchannel的設置,關閉延遲發送
			
			//綁定端口
			ChannelFuture future = bootstrap.bind(10101);
			
			System.out.println("start");
			
			//等待服務端關閉
			future.channel().closeFuture().sync();
			
		} catch (Exception e) {
			e.printStackTrace();
		} finally{
			//釋放資源
			boss.shutdownGracefully();
			worker.shutdownGracefully();
		}
	}
}

​

package com.server;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
/**
 * 服務端消息處理
 * @author -琴獸-
 *
 */
public class ServerHandler extends SimpleChannelInboundHandler<String> {

	@Override
	protected void messageReceived(ChannelHandlerContext ctx, String msg) throws Exception {

		System.out.println(msg);
		
		ctx.channel().writeAndFlush("hi");
		ctx.writeAndFlush("hi");
	}

	/**
	 * 新客戶端接入
	 */
	@Override
	public void channelActive(ChannelHandlerContext ctx) throws Exception {
		System.out.println("channelActive");
	}

	/**
	 * 客戶端斷開
	 */
	@Override
	public void channelInactive(ChannelHandlerContext ctx) throws Exception {
		System.out.println("channelInactive");
	}

	/**
	 * 異常
	 */
	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
		cause.printStackTrace();
	}
	
	
}

二，netty5客戶端入門案例

package com.client;

import java.io.BufferedReader;
import java.io.InputStreamReader;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
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.nio.NioSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

/**
 * netty5的客戶端
 * @author -琴獸-
 *
 */
public class Client {

	public static void main(String[] args) {
		//服務類
		Bootstrap bootstrap = new Bootstrap();
		
		//worker
		EventLoopGroup worker = new NioEventLoopGroup();
		
		try {
			//設置線程池
			bootstrap.group(worker);
			
			//設置socket工廠、
			bootstrap.channel(NioSocketChannel.class);
			
			//設置管道
			bootstrap.handler(new ChannelInitializer<Channel>() {

				@Override
				protected void initChannel(Channel ch) throws Exception {
					ch.pipeline().addLast(new StringDecoder());
					ch.pipeline().addLast(new StringEncoder());
					ch.pipeline().addLast(new ClientHandler());
				}
			});
			
			ChannelFuture connect = bootstrap.connect("127.0.0.1", 10101);
			
			BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
			while(true){
				System.out.println("請輸入：");
				String msg = bufferedReader.readLine();
				connect.channel().writeAndFlush(msg);
			}
			
		} catch (Exception e) {
			 e.printStackTrace();
		} finally{
			worker.shutdownGracefully();
		}
	}
}

package com.client;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
/**
 * 客戶端消息處理
 * @author -琴獸-
 *
 */
public class ClientHandler extends SimpleChannelInboundHandler<String> {

	@Override
	protected void messageReceived(ChannelHandlerContext ctx, String msg) throws Exception {
		System.out.println("客戶端收到消息:"+msg);
	}

}

三，單客戶端多連接程序

package com.client;

import java.io.BufferedReader;
import java.io.InputStreamReader;
/**
 * 啓動類
 *
 */
public class Start {

	public static void main(String[] args) {

		MultClient client = new MultClient();
		client.init(5);
		
		BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
		while(true){
			try {
				System.out.println("請輸入:");
				String msg = bufferedReader.readLine();
				client.nextChannel().writeAndFlush(msg);
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	}

}

package com.client;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
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.nio.NioSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

/**
 * 多連接客戶端
 *
 */
public class MultClient {
	
	/**
	 * 服務類
	 */
	private Bootstrap bootstrap = new Bootstrap();
	
	/**
	 * 會話
	 */
	private List<Channel> channels = new ArrayList<>();
	
	/**
	 * 引用計數
	 */
	private final AtomicInteger index = new AtomicInteger();
	
	/**
	 * 初始化
	 * @param count
	 */
	public void init(int count){
		
		//worker
		EventLoopGroup worker = new NioEventLoopGroup();
		
		//設置線程池
		bootstrap.group(worker);
		
		//設置socket工廠、
		bootstrap.channel(NioSocketChannel.class);
		
		//設置管道
		bootstrap.handler(new ChannelInitializer<Channel>() {

			@Override
			protected void initChannel(Channel ch) throws Exception {
				ch.pipeline().addLast(new StringDecoder());
				ch.pipeline().addLast(new StringEncoder());
				ch.pipeline().addLast(new ClientHandler());
			}
		});
		
		for(int i=1; i<=count; i++){
			ChannelFuture future = bootstrap.connect("192.168.0.103", 10101);
			channels.add(future.channel());
		}
	}
	
	/**
	 * 獲取會話
	 * @return
	 */
	public Channel nextChannel(){
		return getFirstActiveChannel(0);
	}
	
	
	private Channel getFirstActiveChannel(int count){
		Channel channel = channels.get(Math.abs(index.getAndIncrement() % channels.size()));
		if(!channel.isActive()){
			//重連
			reconnect(channel);
			if(count >= channels.size()){
				throw new RuntimeException("no can use channel");
			}
			return getFirstActiveChannel(count + 1);
		}
		return channel;
	}
	
	/**
	 * 重連
	 * @param channel
	 */
	private void reconnect(Channel channel){
		synchronized(channel){
			if(channels.indexOf(channel) == -1){
				return ;
			}
			
			Channel newChannel = bootstrap.connect("192.168.0.103", 10101).channel();
			channels.set(channels.indexOf(channel), newChannel);
		}
	}

}