Java NIO 非阻塞式（non-block） 代码示例

package com.expgiga.NIO;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.ServerSocketChannel;import java.nio.channels.SocketChannel;import java.util.Date;import java.util.Iterator;import java.util.Scanner;/** * 一、使用NIO完成网络通信的三个核心： * 1.通道Channel：负责连接 * java.nio.channels.Channel接口: * |--SelectableChannel *    |--SocketChannel *    |--ServerSocketChannel *    |--DatagramChannel * <p> *    |--Pipe.SinkChannel *    |--Pipe.SourceChannel * <p> * 2.缓冲区Buffer：负责数据的存取 * <p> * 3.选择器Selector：是SelectableChannel的多路复用器。用于监控SelectableChannel的IO状况。 */public class TestNonBlockingNIO {    //客户端    public void client() throws IOException {        //1.获取通道        SocketChannel sChannel = SocketChannel.open(new InetSocketAddress("127.0.0.1", 9898));        //2.切换成非阻塞模式        sChannel.configureBlocking(false);        //3.分配指定大小的缓冲区        ByteBuffer buf = ByteBuffer.allocate(1024);        //4.发送数据给服务端        Scanner scan = new Scanner(System.in);        while (scan.hasNext()) {            String str = scan.next();            buf.put((new Date().toString() + "\n" + str).getBytes());            buf.flip();            sChannel.write(buf);            buf.clear();        }        //5.关闭通道        sChannel.close();    }    //服务端    public void server() throws IOException {        //1.获取通道        ServerSocketChannel ssChannel = ServerSocketChannel.open();        //2.切换成非阻塞模式        ssChannel.configureBlocking(false);        //3.绑定连接        ssChannel.bind(new InetSocketAddress(9898));        //4.获取选择器Selector        Selector selector = Selector.open();        //5.将通道注册到选择器上，并且指定“监听接受事件”        ssChannel.register(selector, SelectionKey.OP_ACCEPT);        //6.轮询式获取选择器上已经准备就绪的事件        while (selector.select() > 0) {            //7.获取当前选择器中所有注册的选择键(已就绪的监听事件)            Iterator<SelectionKey> it = selector.selectedKeys().iterator();            while (it.hasNext()) {                //8.获取准备就绪的事件                SelectionKey sk = it.next();                //9.判断具体是什么事件准备就绪                if (sk.isAcceptable()) {                    //10.若“接收就绪”,获取客户端连接                    SocketChannel sChannel = ssChannel.accept();                    //11.切换成非阻塞的模式                    sChannel.configureBlocking(false);                    //12.将该通道注册到选择器上                    sChannel.register(selector, SelectionKey.OP_READ);                } else if (sk.isReadable()) {                    //13.获取当前选择器上的"读就绪"状态的通道                    SocketChannel sChannel = (SocketChannel) sk.channel();                    //14.读取数据                    ByteBuffer buf = ByteBuffer.allocate(1024);                    int len = 0;                    while ((len = sChannel.read(buf)) > 0) {                        buf.flip();                        System.out.println(new String(buf.array(), 0, len));                        buf.clear();                    }                }                //15.取消选择键SelectionKey                it.remove();            }        }    }}