新IO建立的聊天程序

￡神魔★判官ぃ 2022-08-07 00:20 127阅读 0赞

服务端:

package com.net.scday3;
    
    import java.io.IOException;
    import java.net.InetSocketAddress;
    import java.nio.ByteBuffer;
    import java.nio.channels.Channel;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.ServerSocketChannel;
    import java.nio.channels.SocketChannel;
    import java.nio.charset.Charset;
    
    public class NServer {
    	//用于检测所有Channel的Selector
    	private Selector selector =null;
    	//编写实现编码解码的字符集对象
    	private Charset charset=Charset.forName("UTF-8");
    	
    	public void init() throws IOException{
    			selector=Selector.open();
    			//通过open方法打开一个未绑定的ServerSocketChannel实例
    			ServerSocketChannel server=ServerSocketChannel.open();
    			InetSocketAddress isa=new InetSocketAddress("127.0.0.1",30000);
    			//将该ServerSocketChannel绑定到指定的IP地址
    			server.socket().bind(isa);
    			//设置ServerSocket以非阻塞方式工作	
    			server.configureBlocking(false);
    			//将Server注册到Selector对象
    		    server.register(selector, SelectionKey.OP_ACCEPT);
                while(selector.select()>0){
                	//依次处理selector上的每个已选择的SelectionKey
                	for(SelectionKey sk:selector.selectedKeys()){
                		//从selector上的已选择Key集中删除正在处理的SelctionKey
                			selector.selectedKeys().remove(sk);
                			//如果sk的对应通道包含客户端的连接请求
                			if(sk.isAcceptable()){
                				//调用accept方法接受连接，产生服务器端对应的SocketChannel
                				SocketChannel sc=server.accept();
                				//设置非阻塞模式
                				sc.configureBlocking(false);
                				//将该SocketSchannel也注册到selector
                				sc.register(selector, SelectionKey.OP_READ);
                				//将sk对应的Channel设置成准备接受	其他请求
                				sk.interestOps(SelectionKey.OP_ACCEPT);
                			}
                			//如果sk对应的通过有数据需要读取
                			if(sk.isReadable()){
                				//获取该SelectionKey对应Channel,该Channel中有可读的数据
                				SocketChannel sc=(SocketChannel) sk.channel();
                				//定义准备执行读取数据的ByteBuffer
                				ByteBuffer buff=ByteBuffer.allocate(1024);
                				String content="";
                				//开始读取数据
                			try {
    							 while(sc.read(buff)>0){
                					buff.flip();
                					content+=charset.decode(buff);
                				}
    							 //打印从该sk对应的Channel读取到的数据
    							 System.out.println("===="+content);
    							 //将sk对应的Channel设置成准备下一次读取
    							 sk.interestOps(SelectionKey.OP_READ);
    						}
                			
                			//如果捕捉到该sk对应的Channel出现了异常，即表明该Channel
                			//对应的Client出现了异常，所以从Selector中取消sk的注册
                			
                			catch (Exception e) {
                				//从Selector中删除指定的SelectionKey
                				sk.cancel();
                				if(sk.channel()!=null){
                					sk.channel().close();
                				}
    						  }
                		//如果content的长度大于0	,即聊天信息不为空
                			if(content.length()>0){
                				//遍历该selector里注册的所有SelectKey
                				for(SelectionKey key:selector.keys()){
                					//获取该key对应的channel	
                					Channel targetChannel=key.channel();
                					//如果该channle是SocketChannle对象
                					if(targetChannel instanceof SocketChannel){
                						//将读到的内容放入该Channel中
                						SocketChannel dest=(SocketChannel)targetChannel;
                						dest.write(charset.encode(content));  //客户端会读取该消息内容
                					}
                				}
                			}
                 		}
                	}
                }
    		}
    	public static void main(String[] args) throws IOException {
    		new NServer().init();
    	}
    
    }

客户端：

package com.net.scday3;
    
    import java.io.IOException;
    import java.net.InetSocketAddress;
    import java.nio.ByteBuffer;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.SocketChannel;
    import java.nio.charset.Charset;
    import java.util.Scanner;
    
    public class NClient {
    	//定义检测SocketChannel的Selector对象
    	private  Selector selector=null;
    	//定义处理编码和解码的字符集
    	private Charset charset=Charset.forName("UTF-8");
    	//客户端SocketChannel
    	private SocketChannel sc=null;
    	
    	public void init() throws IOException{
    		selector=Selector.open();
    		InetSocketAddress isa=new InetSocketAddress("127.0.0.1",30000);
            //调用open静态方法创建连接到指定主机的SocketChannel
    		sc=SocketChannel.open(isa);
    		//设置该sc以非阻塞方式工作
    		sc.configureBlocking(false);
    		//将SocketChannel对象注册到指定Selector
    		sc.register(selector, SelectionKey.OP_READ);
    		//启动读取服务器端数据的线程
    		new ClientThread().start();
    		//创建键盘输入流
    		Scanner scan=new Scanner(System.in);
    		while(scan.hasNextLine()){
    			//读取键盘输入
    			String line=scan.nextLine();
    			//将键盘输入的内容输出到SocketChannel中
    			sc.write(charset.encode(line));
    		}
    	}
    	
    	//定义读取服务器端的线程
    	private class ClientThread extends Thread{
    		@Override
    		public void run() {
    			try {
    				while (selector.select()>0){
    					//遍历每个可用IO操作Channel对应的SelectionKey
    					for(SelectionKey sk:selector.selectedKeys()){
    						//删除正在处理的SelectionKey
    						selector.selectedKeys().remove(sk);
    						//如果该SeclectionKey对应的Channel有可读的数据
    						if(sk.isReadable()){
    							//使用NIO读取Channel	中的数据
    							SocketChannel sc=(SocketChannel) sk.channel();
    							ByteBuffer buff=ByteBuffer.allocate(1024);
    							String content="";
    							while(sc.read(buff)>0){
    								sc.read(buff);
    								buff.flip();
    								content+=charset.decode(buff);
    							}
    							//打印输出读取的内容
    							System.out.println("聊天信息:"+content);
    							//为下一次读取做准备
    							sk.interestOps(SelectionKey.OP_READ);
    						}
    					}
    				}
    			} catch (IOException e) {
    				e.printStackTrace();
    			}
    		}
    	}
    	public static void main(String[] args) throws IOException {
    		new NClient().init();
    	}
    }