package cn.zvc.nio;import java.io.IOException;import java.net.InetSocketAddress;import java.net.ServerSocket;import java.nio.ByteBuffer;import java.nio.channels.ClosedChannelException;import java.nio.channels.SelectionKey;import java.nio.channels.Selector;import java.nio.channels.ServerSocketChannel;import java.nio.channels.SocketChannel;import java.util.Iterator;import java.util.Set;public class NIOServer {	private int blockSize = 4096;	private ByteBuffer sendBuffer = ByteBuffer.allocate(blockSize);		private ByteBuffer receiveBuffer = ByteBuffer.allocate(blockSize);	private Selector selector;		private int flag = 1;	public NIOServer(int port) throws IOException {		ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();		//设置是否阻塞		serverSocketChannel.configureBlocking(false);		ServerSocket serverSocket = serverSocketChannel.socket();		serverSocket.bind(new InetSocketAddress(port));		selector = Selector.open();				serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);				System.out.println("server start:" + port);	}			public void linsten() throws IOException{		while(true) {			selector.select();			Set
    
      selectionKeys = selector.selectedKeys();			Iterator
     
       it = selectionKeys.iterator();			while(it.hasNext()) {				SelectionKey sk = it.next();				it.remove();				//业务逻辑				handleKey(sk);			}		}	}		public void handleKey(SelectionKey sk) throws IOException{		ServerSocketChannel server = null;		SocketChannel client = null;		String reviceText;		String sendText;		int count = 0;		if(sk.isAcceptable()){			server = (ServerSocketChannel) sk.channel();			client = server.accept();			client.configureBlocking(false);			client.register(selector, sk.OP_READ);					} else if(sk.isReadable()) {			client = (SocketChannel) sk.channel();			count = client.read(receiveBuffer);			if(count>0){				reviceText = new String(receiveBuffer.array(),0,count);				System.out.println("服务端接受到客户端的信息："+ reviceText);				client.register(selector, SelectionKey.OP_WRITE);			} 		} else if(sk.isWritable()){			receiveBuffer.clear();			client = (SocketChannel) sk.channel();			sendText = "msg send to client:"+ flag;			sendBuffer.put(sendText.getBytes());			sendBuffer.flip();			client.write(sendBuffer);			System.out.println("服务端发送给客户端："+ sendText);		}					}	public static void main(String[] args) {			}}