Java NIO 聊天室实例

最近写了个Java NIO聊天室聊天的程序，NIO学习起来比较困难的，我的代码能给大家起到一个抛砖引玉的作用！

服务端：

package test.javanio;  

/**
 * @author
 * @version
 * CreateTime：2010-12-1 下午05:12:11
 * Description：
 */
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.logging.Level;
import java.util.logging.Logger;  

public class MySocketServer implements Runnable {  

    private boolean running;  

    private Selector selector;
    String writeMsg;
    StringBuffer sb = new StringBuffer();
    SelectionKey ssckey;  

    public MySocketServer() {  

        running = true;  

    }  

    public void init() {
        try {
            selector = Selector.open();
            ServerSocketChannel ssc = ServerSocketChannel.open();
            ssc.configureBlocking(false);
            ssc.socket().bind(new InetSocketAddress(2345));
            ssckey = ssc.register(selector, SelectionKey.OP_ACCEPT);
            System.out.println("server is starting..." + new Date());
        } catch (IOException ex) {
            Logger.getLogger(MySocketServer.class.getName()).log(Level.SEVERE,
                    null, ex);
        }
    }  

    public static void main(String[] args) {
        MySocketServer server = new MySocketServer();
        new Thread(server).start();  

    }  

    public void execute() {
        try {
            while (running) {
                int num = selector.select();
                if (num > 0) {
                    Iterator<SelectionKey> it = selector.selectedKeys()
                            .iterator();
                    while (it.hasNext()) {
                        SelectionKey key = it.next();
                        it.remove();
                        if (!key.isValid())
                            continue;
                        if (key.isAcceptable()) {
                            System.out.println("isAcceptable");
                            getConn(key);
                        } else if (key.isReadable()) {
                            System.out.println("isReadable");
                            readMsg(key);
                        }  

                        else if (key.isValid() && key.isWritable()) {
                            if (writeMsg != null) {
                                System.out.println("isWritable");
                                writeMsg(key);
                            }  

                        }  

                        else
                            break;  

                    }  

                }
                Thread.yield();
            }  

        } catch (IOException ex) {
            Logger.getLogger(MySocketServer.class.getName()).log(Level.SEVERE,
                    null, ex);
        }
    }  

    private void getConn(SelectionKey key) throws IOException {
        ServerSocketChannel ssc = (ServerSocketChannel) key.channel();
        SocketChannel sc = ssc.accept();
        sc.configureBlocking(false);
        sc.register(selector, SelectionKey.OP_READ);
        System.out.println("build connection :"
                + sc.socket().getRemoteSocketAddress());
    }  

    private void readMsg(SelectionKey key) throws IOException {
        sb.delete(0, sb.length());
        SocketChannel sc = (SocketChannel) key.channel();
        System.out.print(sc.socket().getRemoteSocketAddress() + " ");
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        buffer.clear();
        int len = 0;
        StringBuffer sb = new StringBuffer();
        while ((len = sc.read(buffer)) > 0) {
            buffer.flip();
            sb.append(new String(buffer.array(), 0, len));
        }
        if (sb.length() > 0)
            System.out.println("get from client:" + sb.toString());
        if (sb.toString().trim().toLowerCase().equals("quit")) {
            sc.write(ByteBuffer.wrap("BYE".getBytes()));
            System.out.println("client is closed "
                    + sc.socket().getRemoteSocketAddress());
            key.cancel();
            sc.close();
            sc.socket().close();  

        } else {
            String toMsg = sc.socket().getRemoteSocketAddress() + "said:"
                    + sb.toString();
            System.out.println(toMsg);  

            writeMsg = toMsg;  

            /*
             * Iterator<SelectionKey> it=key.selector().keys().iterator();
             *
             * while(it.hasNext()){ SelectionKey skey=it.next();
             * if(skey!=key&&skey!=ssckey){ SocketChannel client=(SocketChannel)
             * skey.channel(); client.write(ByteBuffer.wrap(toMsg.getBytes()));
             * }
             *
             * }
             */ 

            /*
             *
             * key.attach(toMsg);
             * key.interestOps(key.interestOps()|SelectionKey.OP_WRITE);
             */
            Iterator<SelectionKey> it = key.selector().keys().iterator();  

            while (it.hasNext()) {
                SelectionKey skey = it.next();
                if (skey != key && skey != ssckey) {
                    if (skey.attachment() != null) {
                        String str = (String) skey.attachment();
                        skey.attach(str + toMsg);
                    } else {
                        skey.attach(toMsg);
                    }
                    skey
                            .interestOps(skey.interestOps()
                                    | SelectionKey.OP_WRITE);
                }  

            }
            selector.wakeup();// 可有可无  

        }  

    }  

    public void run() {
        init();
        execute();
    }  

    private void writeMsg(SelectionKey key) throws IOException {  

        System.out.println("++++enter write+++");
        SocketChannel sc = (SocketChannel) key.channel();
        String str = (String) key.attachment();  

        sc.write(ByteBuffer.wrap(str.getBytes()));
        key.interestOps(SelectionKey.OP_READ);
    }
} 

客户端：

package test.javanio;  

/**
 * @author
 * @version
 * CreateTime：2010-12-1 下午05:12:46
 * Description：
 */
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.Currency.*;  

public class MySocketClient implements Runnable {
    Selector selector;  

    boolean running;  

    SocketChannel sc;  

    public MySocketClient() {
        running = true;  

    }  

    public void init() {
        try {
            sc = SocketChannel.open();
            sc.configureBlocking(false);
            sc.connect(new InetSocketAddress("localhost", 2345));  

        } catch (IOException ex) {
            Logger.getLogger(MySocketClient.class.getName()).log(Level.SEVERE,
                    null, ex);
        }
    }  

    public static void main(String[] args) {  

        MySocketClient client = new MySocketClient();
        new Thread(client).start();
    }  

    public void execute() {  

        int num = 0;
        try {
            while (!sc.finishConnect()) {
            }
        } catch (IOException ex) {
            Logger.getLogger(MySocketClient.class.getName()).log(Level.SEVERE,
                    null, ex);
        }  

        ReadKeyBoard rkb = new ReadKeyBoard();
        new Thread(rkb).start();
        while (running) {
            try {  

                ByteBuffer buffer = ByteBuffer.allocate(1024);
                buffer.clear();  

                StringBuffer sb = new StringBuffer();
                Thread.sleep(500);  

                while ((num = sc.read(buffer)) > 0) {
                    sb.append(new String(buffer.array(), 0, num));
                    buffer.clear();
                }
                if (sb.length() > 0)
                    System.out.println(sb.toString());
                if (sb.toString().toLowerCase().trim().equals("bye")) {
                    System.out.println("closed....");  

                    sc.close();
                    sc.socket().close();
                    rkb.close();
                    running = false;
                }
            } catch (InterruptedException ex) {
                Logger.getLogger(MySocketClient.class.getName()).log(
                        Level.SEVERE, null, ex);
            } catch (IOException ex) {
                Logger.getLogger(MySocketClient.class.getName()).log(
                        Level.SEVERE, null, ex);
            }
        }  

    }  

    public void run() {
        init();
        execute();
    }  

    class ReadKeyBoard implements Runnable {  

        boolean running2 = true;  

        public ReadKeyBoard() {  

        }  

        public void close() {
            running2 = false;
        }  

        public void run() {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    System.in));
            while (running2) {
                try {
                    System.out.println("enter some commands:");
                    String str = reader.readLine();
                    sc.write(ByteBuffer.wrap(str.getBytes()));  

                } catch (IOException ex) {
                    Logger.getLogger(ReadKeyBoard.class.getName()).log(
                            Level.SEVERE, null, ex);
                }
            }  

        }  

    }
} 

原文地址：http://gcguchao8888-sina-com.iteye.com/blog/839021