Java NIO Reactor模式

package com.zzq.nio.reactor;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.Iterator;public class Reactor implements Runnable {    private ServerSocketChannel serverSocketChannel = null;    private Selector            selector            = null;    public Reactor() {        try {            selector = Selector.open();            serverSocketChannel = ServerSocketChannel.open();            serverSocketChannel.configureBlocking(false);            serverSocketChannel.socket().bind(new InetSocketAddress(8888));            SelectionKey selectionKey = serverSocketChannel.register(selector,                SelectionKey.OP_ACCEPT);            selectionKey.attach(new Acceptor());            System.out.println("服务器启动正常!");        } catch (IOException e) {            System.out.println("启动服务器时出现异常!");            e.printStackTrace();        }    }    public void run() {        while (true) {            try {                selector.select();                Iterator<SelectionKey> iter = selector.selectedKeys().iterator();                while (iter.hasNext()) {                    SelectionKey selectionKey = iter.next();                    dispatch((Runnable) selectionKey.attachment());                    iter.remove();                }            } catch (IOException e) {                e.printStackTrace();            }        }    }    public void dispatch(Runnable runnable) {        if (runnable != null) {            runnable.run();        }    }    public static void main(String[] args) {        new Thread(new Reactor()).start();    }    class Acceptor implements Runnable {        public void run() {            try {                SocketChannel socketChannel = serverSocketChannel.accept();                if (socketChannel != null) {                    System.out.println("接收到来自客户端（"                                       + socketChannel.socket().getInetAddress().getHostAddress()                                       + "）的连接");                    new Handler(selector, socketChannel);                }            } catch (IOException e) {                e.printStackTrace();            }        }    }}class Handler implements Runnable {    private static final int READ_STATUS  = 1;    private static final int WRITE_STATUS = 2;    private SocketChannel    socketChannel;    private SelectionKey     selectionKey;    private int              status       = READ_STATUS;    public Handler(Selector selector, SocketChannel socketChannel) {        this.socketChannel = socketChannel;        try {            socketChannel.configureBlocking(false);            selectionKey = socketChannel.register(selector, 0);            selectionKey.interestOps(SelectionKey.OP_READ);            selectionKey.attach(this);            selector.wakeup();        } catch (IOException e) {            e.printStackTrace();        }    }    public void run() {        try {            if (status == READ_STATUS) {                read();                selectionKey.interestOps(SelectionKey.OP_WRITE);                status = WRITE_STATUS;            } else if (status == WRITE_STATUS) {                process();                selectionKey.cancel();                System.out.println("服务器发送消息成功!");            }        } catch (IOException e) {            e.printStackTrace();        }    }    public void read() throws IOException {        ByteBuffer buffer = ByteBuffer.allocate(1024);        socketChannel.read(buffer);        System.out.println("接收到来自客户端（" + socketChannel.socket().getInetAddress().getHostAddress()                           + "）的消息：" + new String(buffer.array()));    }    public void process() throws IOException {        String content = "Hello World!";        ByteBuffer buffer = ByteBuffer.wrap(content.getBytes());        socketChannel.write(buffer);    }}