NIO Java NIO 通讯的简单示例，,import java.

NIO Java NIO 通讯的简单示例，,import java.

import java.io.*;import java.nio.*;import java.nio.channels.*;import java.net.*;import java.util.*;import java.nio.charset.*;import java.lang.*;public class NonBlockingServer{    public Selector sel = null;    public ServerSocketChannel server = null;    public SocketChannel socket = null;    public int port = 4900;    String result = null;    public NonBlockingServer()    {        System.out.println("Inside default ctor");    }    public NonBlockingServer(int port)    {        System.out.println("Inside the other ctor");        port = port;    }    public void initializeOperations() throws IOException,UnknownHostException    {        System.out.println("Inside initialization");        sel = Selector.open();        server = ServerSocketChannel.open();        server.configureBlocking(false);        InetAddress ia = InetAddress.getLocalHost();        InetSocketAddress isa = new InetSocketAddress(ia,port);        server.socket().bind(isa);    }    public void startServer() throws IOException    {        System.out.println("Inside startserver");        initializeOperations();        System.out.println("Abt to block on select()");        SelectionKey acceptKey = server.register(sel, SelectionKey.OP_ACCEPT );         while (acceptKey.selector().select() > 0 )        {               Set readyKeys = sel.selectedKeys();            Iterator it = readyKeys.iterator();            while (it.hasNext()) {                SelectionKey key = (SelectionKey)it.next();                it.remove();                if (key.isAcceptable()) {                    System.out.println("Key is Acceptable");                    ServerSocketChannel ssc = (ServerSocketChannel) key.channel();                    socket = (SocketChannel) ssc.accept();                    socket.configureBlocking(false);                    SelectionKey another = socket.register(sel,SelectionKey.OP_READ|SelectionKey.OP_WRITE);                }                if (key.isReadable()) {                    System.out.println("Key is readable");                    String ret = readMessage(key);                    if (ret.length() > 0) {                        writeMessage(socket,ret);                    }                }                if (key.isWritable()) {                    //System.out.println("The key is writable");                    String ret = readMessage(key);                    socket = (SocketChannel)key.channel();                    if (result.length() > 0 ) {                        writeMessage(socket,ret);                    }                }            }        }    }    public void writeMessage(SocketChannel socket,String ret)    {        System.out.println("Inside the loop");        if (ret.equals("quit") || ret.equals("shutdown")) {            return;        }        File file = new File(ret);        try        {            RandomAccessFile rdm = new RandomAccessFile(file,"r");            FileChannel fc = rdm.getChannel();            ByteBuffer buffer = ByteBuffer.allocate(1024);            fc.read(buffer);            buffer.flip();            Charset set = Charset.forName("us-ascii");            CharsetDecoder dec = set.newDecoder();            CharBuffer charBuf = dec.decode(buffer);            System.out.println(charBuf.toString());            buffer = ByteBuffer.wrap((charBuf.toString()).getBytes());            int nBytes = socket.write(buffer);            System.out.println("nBytes = "+nBytes);                result = null;        }        catch(Exception e)        {            e.printStackTrace();        }    }    public String readMessage(SelectionKey key)    {        int nBytes = 0;        socket = (SocketChannel)key.channel();        ByteBuffer buf = ByteBuffer.allocate(1024);        try        {            nBytes = socket.read(buf);            buf.flip();            Charset charset = Charset.forName("us-ascii");            CharsetDecoder decoder = charset.newDecoder();            CharBuffer charBuffer = decoder.decode(buf);            result = charBuffer.toString();        }        catch(IOException e)        {            e.printStackTrace();        }        return result;    }    public static void main(String args[])    {        NonBlockingServer nb = new NonBlockingServer();        try        {            nb.startServer();        }        catch (IOException e)        {            e.printStackTrace();            System.exit(-1);        }    }}``````javaimport java.nio.*;import java.nio.channels.*;import java.net.*;import java.io.*;import java.nio.channels.spi.*;import java.nio.charset.*;import java.lang.*;public class Client{    public SocketChannel client = null;    public InetSocketAddress isa = null;    public RecvThread rt = null;    public Client()    {    }    public void makeConnection()    {        int result = 0;        try        {            client = SocketChannel.open();                isa = new InetSocketAddress("liudong",4900);            client.connect(isa);            client.configureBlocking(false);            receiveMessage();            }        catch(UnknownHostException e)        {            e.printStackTrace();        }        catch(IOException e)        {            e.printStackTrace();        }        while ((result = sendMessage()) != -1)        {        }        try        {            client.close();            System.exit(0);        }        catch(IOException e)        {            e.printStackTrace();        }    }    public int sendMessage()    {        System.out.println("Inside SendMessage");        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));        String msg = null;        ByteBuffer bytebuf = ByteBuffer.allocate(1024);        int nBytes = 0;        try        {            msg = in.readLine();            System.out.println("msg is "+msg);            bytebuf = ByteBuffer.wrap(msg.getBytes());            nBytes = client.write(bytebuf);            System.out.println("nBytes is "+nBytes);            if (msg.equals("quit") || msg.equals("shutdown")) {                System.out.println("time to stop the client");                interruptThread();                try                {                    Thread.sleep(5000);                }                catch(Exception e)                {                    e.printStackTrace();                }                client.close();                return -1;            }        }        catch(IOException e)        {            e.printStackTrace();        }        System.out.println("Wrote "+nBytes +" bytes to the server");        return nBytes;    }    public void receiveMessage()    {        rt = new RecvThread("Receive THread",client);        rt.start();    }    public void interruptThread()    {        rt.val = false;    }    public static void main(String args[])    {        Client cl = new Client();        cl.makeConnection();    }    public class RecvThread extends Thread    {        public SocketChannel sc = null;        public boolean val = true;        public RecvThread(String str,SocketChannel client)        {            super(str);            sc = client;        }        public void run() {            System.out.println("Inside receivemsg");            int nBytes = 0;            ByteBuffer buf = ByteBuffer.allocate(2048);            try            {                while (val)                {                    while ( (nBytes = nBytes = client.read(buf)) > 0){                        buf.flip();                        Charset charset = Charset.forName("us-ascii");                        CharsetDecoder decoder = charset.newDecoder();                        CharBuffer charBuffer = decoder.decode(buf);                        String result = charBuffer.toString();                                    System.out.println(result);                        buf.flip();                    }                }            }            catch(IOException e)            {                e.printStackTrace();            }        }    }}