javanio 实现socket通信

╰半夏微凉° 2022-07-28 09:37 185阅读 0赞

package io.nio;
    
    import java.net.InetSocketAddress;
    import java.nio.ByteBuffer;
    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;
    import java.util.Iterator;
    import java.util.Set;
    
    /**
     * 服务端
     * @author zzh
     *
     */
    public class NIOSocketServer {
    	
    	public static void main(String[] args) throws Exception {
    		
    		//创建选择器
    		Selector selector = Selector.open();
    		//创建一个socket通道
    		ServerSocketChannel ssc = ServerSocketChannel.open();
    		//通道为非阻塞
    		ssc.configureBlocking(false);
    		//绑定端口号
    		ssc.bind(new InetSocketAddress("127.0.0.1", 8080));
    		//关注接受到客户端连接的事件
    		ssc.register(selector, SelectionKey.OP_ACCEPT);
    		//用于字节和字符的转换
    		Charset charset = Charset.forName("UTF-8");
    		
    		
    		//select()阻塞到至少有一个通道在你注册的事件上就绪了
    		while (selector.select() > 0) {
    			// 一次处理selector上的每个选择的SelectionKey 
    			Set<SelectionKey> selectedKeys = selector.selectedKeys();
    			Iterator<SelectionKey> iterator = selectedKeys.iterator();
    			while (iterator.hasNext()) {
    				SelectionKey key = iterator.next();
    				//客户端连接了
    				if ((key.readyOps() & SelectionKey.OP_ACCEPT) == SelectionKey.OP_ACCEPT) {
    					ServerSocketChannel ssChannel = (ServerSocketChannel) key.channel();
    					SocketChannel sc = ssChannel.accept();
    					sc.configureBlocking(false);
    					sc.register(selector, SelectionKey.OP_READ);
    					iterator.remove();
    				//channal中有数据读
    				} else if ((key.readyOps() & SelectionKey.OP_READ) == SelectionKey.OP_READ) {
    					//创建缓冲区
    					ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
    					
    					SocketChannel sc = (SocketChannel) key.channel();
    					while (sc.read(byteBuffer) > 0) {//读数据到缓存
    //						byteBuffer.clear();
    //						int n = sc.read(byteBuffer);
    //						if (n <= 0) {
    //							break;
    //						}
    						//反转此缓冲区，调用此方法为一系列通道写入或相对获取 操作做好准备
    						byteBuffer.flip();
    						System.out.println("服务端读出了：" +  charset.decode(byteBuffer));
    					}
    					iterator.remove();
    				}
    			}
    		}
    	}
    
    }

package io.nio;
    
    import java.net.InetSocketAddress;
    import java.nio.channels.SelectionKey;
    import java.nio.channels.Selector;
    import java.nio.channels.SocketChannel;
    import java.nio.charset.Charset;
    import java.util.Scanner;
    
    /**
     * 客户端
     * @author zzh
     *
     */
    public class NIOSocketClient {
    
    	public static void main(String[] args) throws Exception {
    		
    		//Selector允许单线程处理多个 Channel
    //		Selector selector = Selector.open();
    		
    		InetSocketAddress address = new InetSocketAddress("127.0.0.1", 8080);
    		
    		SocketChannel channel = SocketChannel.open(address);
    		
    		channel.configureBlocking(false);
    		//监测读事件
    //		channel.register(selector, SelectionKey.OP_READ);
    		
    		
    		Charset charset = Charset.forName("UTF-8");
    		
    		Scanner scan = new Scanner(System.in); 
            while(scan.hasNextLine()) {  
                //读取键盘的输入  
                String line = scan.nextLine();  
                System.out.println("读入数据" + line);
                //将内容输出到SocketChanenel中 
                channel.write(charset.encode(line));  
            }
    	}
    }