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JAVA Netty實(shí)現(xiàn)聊天室+私聊功能的示例代碼

更新時(shí)間：2020年08月20日 09:08:33 作者：-韌-

這篇文章主要介紹了JAVA Netty實(shí)現(xiàn)聊天室+私聊功能的示例代碼,文中通過示例代碼介紹的非常詳細(xì)，對大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價(jià)值，需要的朋友們下面隨著小編來一起學(xué)習(xí)學(xué)習(xí)吧

功能介紹

使用Netty框架實(shí)現(xiàn)聊天室功能，服務(wù)器可監(jiān)控客戶端上下限狀態(tài)，消息轉(zhuǎn)發(fā)。同時(shí)實(shí)現(xiàn)了點(diǎn)對點(diǎn)私聊功能。技術(shù)點(diǎn)我都在代碼中做了備注，這里不再重復(fù)寫了。希望能給想學(xué)習(xí)netty的同學(xué)一點(diǎn)參考。

服務(wù)器代碼

服務(wù)器入口代碼

package nio.test.netty.groupChat;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
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.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.GenericFutureListener;

/**
 * netty群聊 服務(wù)器端
 * @author zhang
 *
 */
public class NettyChatServer {
	private int port;
	
	public NettyChatServer(int port){
		this.port = port;
	}
	
	//初始化 netty服務(wù)器
	private void init() throws Exception{
		EventLoopGroup boss = new NioEventLoopGroup(1);
		EventLoopGroup work = new NioEventLoopGroup(16);
		try {
			ServerBootstrap boot = new ServerBootstrap();
			boot.group(boss,work);
			boot.channel(NioServerSocketChannel.class);//設(shè)置boss selector建立channel使用的對象
			boot.option(ChannelOption.SO_BACKLOG, 128);//boss 等待連接的 隊(duì)列長度
			boot.childOption(ChannelOption.SO_KEEPALIVE, true); //讓客戶端保持長期活動(dòng)狀態(tài)
			boot.childHandler(new ChannelInitializer<SocketChannel>() {

				@Override
				protected void initChannel(SocketChannel ch) throws Exception {
					//從channel中獲取pipeline 并往里邊添加Handler
					ChannelPipeline pipeline = ch.pipeline();
					pipeline.addLast("encoder",new StringEncoder());
					pipeline.addLast("decoder",new StringDecoder());
					pipeline.addLast(new ServerMessageHandler());//自定義Handler來處理消息
				}
			});
			System.out.println("服務(wù)器開始啟動(dòng)...");
			//綁定端口 
			ChannelFuture channelFuture = boot.bind(port).sync();
			channelFuture.addListener(new GenericFutureListener<Future<? super Void>>() {

				@Override
				public void operationComplete(Future<? super Void> future)
						throws Exception {
					if(future.isSuccess()){
						System.out.println("服務(wù)器正在啟動(dòng)...");
					}
					if(future.isDone()){
						System.out.println("服務(wù)器啟動(dòng)成功...OK");
					}
					
				}
			});
			//監(jiān)聽channel關(guān)閉
			channelFuture.channel().closeFuture().sync();
			channelFuture.addListener(new GenericFutureListener<Future<? super Void>>() {

				@Override
				public void operationComplete(Future<? super Void> future)
						throws Exception {
					if(future.isCancelled()){
						System.out.println("服務(wù)器正在關(guān)閉..");
					}
					if(future.isCancellable()){
						System.out.println("服務(wù)器已經(jīng)關(guān)閉..OK");
					}
					
				}
			});
			
		}finally{
			boss.shutdownGracefully();
			work.shutdownGracefully();
		}
	}
	/**
	 * 啟動(dòng)服務(wù)器 main 函數(shù)
	 * @param args
	 * @throws Exception
	 */
	public static void main(String[] args) throws Exception {
		new NettyChatServer(9090).init();

	}

}

服務(wù)器端消息處理Handler

package nio.test.netty.groupChat;

import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.util.concurrent.GlobalEventExecutor;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
/**
 * 自定義 服務(wù)器端消息處理Handler
 * @author zhang
 *
 */
public class ServerMessageHandler extends SimpleChannelInboundHandler<String>{
	/**
	 * 管理全局的channel
	 * GlobalEventExecutor.INSTANCE 全局事件監(jiān)聽器
	 * 一旦將channel 加入 ChannelGroup 就不要用手動(dòng)去
	 * 管理channel的連接失效后移除操作，他會(huì)自己移除
	 */
	private static ChannelGroup channels = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
	/**
	 * 為了實(shí)現(xiàn)私聊功能，這里key存儲用戶的唯一標(biāo)識，
	 * 我保存 客戶端的端口號
	 * 當(dāng)然 這個(gè)集合也需要自己去維護(hù) 用戶的上下線 不能像 ChannelGroup那樣自己去維護(hù)
	 */
	private static Map<String,Channel> all = new HashMap<String,Channel>();
	
	private SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
	/**
	 * 處理收到的消息
	 */
	@Override
	protected void channelRead0(ChannelHandlerContext ctx, String msg)
			throws Exception {
		Channel channel = ctx.channel();
		/**
		 * 這里簡單判斷 如果內(nèi)容里邊包含#那么就是私聊
		 */
		if(msg.contains("#")){
			String id = msg.split("#")[0];
			String body = msg.split("#")[1];
			Channel userChannel = all.get(id);
			String key = channel.remoteAddress().toString().split(":")[1];
			userChannel.writeAndFlush(sf.format(new Date())+"\n 【用戶】 "+key+" 說 : "+body);
			return;
		}
		
		//判斷當(dāng)前消息是不是自己發(fā)送的
		for(Channel c : channels){
			String addr = c.remoteAddress().toString();
			if(channel !=c){
				c.writeAndFlush(sf.format(new Date())+"\n 【用戶】 "+addr+" 說 : "+msg);
			}else{
				c.writeAndFlush(sf.format(new Date())+"\n 【自己】 "+addr+" 說 : "+msg);
			}
		}
		
	}
	/**
	 * 建立連接以后第一個(gè)調(diào)用的方法
	 */
	@Override
	public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
		Channel channel = ctx.channel();
		String addr = channel.remoteAddress().toString();
		/**
		 * 這里 ChannelGroup 底層封裝會(huì)遍歷給所有的channel發(fā)送消息
		 * 
		 */
		channels.writeAndFlush(sf.format(new Date())+"\n 【用戶】 "+addr+" 加入聊天室 ");
		channels.add(channel);
		String key = channel.remoteAddress().toString().split(":")[1];
		all.put(key, channel);
	}
	/**
	 * channel連接狀態(tài)就緒以后調(diào)用
	 */
	@Override
	public void channelActive(ChannelHandlerContext ctx) throws Exception {
		String addr = ctx.channel().remoteAddress().toString();
		System.out.println(sf.format(new Date())+" \n【用戶】 "+addr+" 上線 ");
	}
	/**
	 * channel連接狀態(tài)斷開后觸發(fā)
	 */
	@Override
	public void channelInactive(ChannelHandlerContext ctx) throws Exception {
		String addr = ctx.channel().remoteAddress().toString();
		System.out.println(sf.format(new Date())+" \n【用戶】 "+addr+" 下線 ");
		//下線移除
		String key = ctx.channel().remoteAddress().toString().split(":")[1];
		all.remove(key);
	}
	/**
	 * 連接發(fā)生異常時(shí)觸發(fā)
	 */
	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
			throws Exception {
		//System.out.println("連接發(fā)生異常！");
		ctx.close();
	}
	/**
	 * 斷開連接會(huì)觸發(fā)該消息
	 * 同時(shí)當(dāng)前channel 也會(huì)自動(dòng)從ChannelGroup中被移除
	 */
	@Override
	public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
		Channel channel = ctx.channel();
		String addr = channel.remoteAddress().toString();
		/**
		 * 這里 ChannelGroup 底層封裝會(huì)遍歷給所有的channel發(fā)送消息
		 * 
		 */
		channels.writeAndFlush(sf.format(new Date())+"\n 【用戶】 "+addr+" 離開了 ");
		//打印 ChannelGroup中的人數(shù)
		System.out.println("當(dāng)前在線人數(shù)是:"+channels.size());
		System.out.println("all："+all.size());
	}

	
}

客戶端主方法代碼

package nio.test.netty.groupChat;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
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;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.GenericFutureListener;

import java.util.Scanner;

public class NettyChatClient {

	private String ip;
	
	private int port;
	
	public NettyChatClient(String ip,int port){
		this.ip = ip;
		this.port = port;
	}
	/**
	 * 初始化客戶
	 */
	private void init() throws Exception{
		//創(chuàng)建監(jiān)聽事件的監(jiān)聽器
		EventLoopGroup work = new NioEventLoopGroup();
		try {
			Bootstrap boot = new Bootstrap();
			boot.group(work);
			boot.channel(NioSocketChannel.class);
			boot.handler(new ChannelInitializer<NioSocketChannel>() {

				@Override
				protected void initChannel(NioSocketChannel ch)
						throws Exception {
					ChannelPipeline pipeline = ch.pipeline();
					pipeline.addLast("encoder",new StringEncoder());
					pipeline.addLast("decoder",new StringDecoder());
					pipeline.addLast(new ClientMessageHandler());
					
				}
			});
			
			ChannelFuture channelFuture = boot.connect(ip, port).sync();
			channelFuture.addListener(new GenericFutureListener<Future<? super Void>>() {

				@Override
				public void operationComplete(Future<? super Void> future)
						throws Exception {
					if(future.isSuccess()){
						System.out.println("客戶端啟動(dòng)中...");
					}
					if(future.isDone()){
						System.out.println("客戶端啟動(dòng)成功...OK！");
					}
				}
			});
			System.out.println(channelFuture.channel().localAddress().toString());
			System.out.println("#################################################");
			System.out.println("~~~~~~~~~~~~~~端口號#消息內(nèi)容~~這樣可以給單獨(dú)一個(gè)用戶發(fā)消息~~~~~~~~~~~~~~~~~~");
			System.out.println("#################################################");
			
			/**
			 * 這里用控制臺輸入數(shù)據(jù)
			 */
			Channel channel = channelFuture.channel();
			//獲取channel
			Scanner scanner = new Scanner(System.in);
			while(scanner.hasNextLine()){
				String str = scanner.nextLine();
				channel.writeAndFlush(str+"\n");
			}
			channelFuture.channel().closeFuture().sync();
			scanner.close();
		} finally {
			work.shutdownGracefully();
		}
	}
	
	/**
	 * 主方法入口
	 * @param args
	 * @throws Exception
	 */
	public static void main(String[] args) throws Exception{

		new NettyChatClient("127.0.0.1",9090).init();
	}

}

客戶端消息處理Handler

package nio.test.netty.groupChat;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
/**
 * 客戶點(diǎn)消息處理 Handler
 * @author zhang
 *
 */
public class ClientMessageHandler extends SimpleChannelInboundHandler<String> {

	/**
	 * 處理收到的消息
	 */
	@Override
	protected void channelRead0(ChannelHandlerContext ctx, String msg)
			throws Exception {
		System.out.println(msg);
		
	}
	/**
	 * 連接異常后觸發(fā)
	 */
	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
			throws Exception {
		ctx.close();
		
	}
}

測試結(jié)果

啟動(dòng)了四個(gè)客戶端服務(wù)器端日志效果如下：