UDP/IP + NIO实现系统间通信

转自:http://blog.sina.com.cn/s/blog_d459b83c0101ewhe.html

package com.java.dao;

 

import java.net.DatagramSocket;

import java.net.InetSocketAddress;

import java.nio.ByteBuffer;

import java.nio.CharBuffer;

import java.nio.channels.DatagramChannel;

import java.nio.channels.SelectionKey;

import java.nio.channels.Selector;

import java.nio.charset.Charset;

import java.util.Iterator;

import java.util.Set;

 

 

public class UDPServer extends Thread {

   public void run() {

      Selector selector = null;

      try {

        DatagramChannel channel = DatagramChannel.open();

        DatagramSocket socket = channel.socket();

        channel.configureBlocking(false);

        socket.bind(new InetSocketAddress(5057));

 

        selector = Selector.open();

        channel.register(selector, SelectionKey.OP_READ);

      } catch (Exception e) {

        e.printStackTrace();

      }

 

      ByteBuffer byteBuffer = ByteBuffer.allocate(65536);

      while (true) {

        try {

           int eventsCount = selector.select();

           if (eventsCount > 0) {

              SetselectedKeys = selector.selectedKeys();

              Iteratoriterator = selectedKeys.iterator();

              while (iterator.hasNext()) {

                 SelectionKey sk = (SelectionKey) iterator.next();

                 iterator.remove();

                 // 读事件

                 if (sk.isReadable()) {

                    DatagramChannel datagramChannel = (DatagramChannel) sk

                         .channel();

                    datagramChannel.receive(byteBuffer);

                    byteBuffer.flip();

 

                    // 测试：通过将收到的ByteBuffer首先通过缺省的编码解码成CharBuffer 再输出

                    CharBuffer charBuffer = Charset.defaultCharset()

                         .decode(byteBuffer);

                    System.out.println("receive message:"

                         + charBuffer.toString());

                    byteBuffer.clear();

 

                    String echo = "This is the reply message from 服务器。";

                    ByteBuffer buffer = Charset.defaultCharset()

                         .encode(echo);

                    datagramChannel.write(buffer);

                 }

              }

           }

        } catch (Exception e) {

           e.printStackTrace();

        }

      }

   }

 

   public static void main(String[] args) {

      new UDPServer().start();

   }

}

package com.java.dao;

 

import java.net.InetSocketAddress;

import java.net.SocketAddress;

import java.nio.ByteBuffer;

import java.nio.channels.DatagramChannel;

import java.nio.channels.SelectionKey;

import java.nio.channels.Selector;

import java.nio.charset.Charset;

import java.util.Iterator;

import java.util.Set;

 

 

public class UDPClient extends Thread {

   public void run() {

      DatagramChannel channel = null;

      Selector selector = null;

      try {

        channel = DatagramChannel.open();

        channel.configureBlocking(false);

        SocketAddress sa = new InetSocketAddress("localhost", 5057);

        channel.connect(sa);

      } catch (Exception e) {

        e.printStackTrace();

      }

 

      try {

        selector = Selector.open();

        channel.register(selector, SelectionKey.OP_READ);

        channel.write(Charset.defaultCharset().encode("Tell me your time"));

      } catch (Exception e) {

        e.printStackTrace();

      }

 

      ByteBuffer byteBuffer = ByteBuffer.allocate(100);

      while (true) {

        try {

           int eventsCount = selector.select();

           if (eventsCount > 0) {

              SetselectedKeys = selector.selectedKeys();

              Iteratoriterator = selectedKeys.iterator();

              while (iterator.hasNext()) {

                 SelectionKey sk = (SelectionKey) iterator.next();

                 iterator.remove();

                 // 读事件

                 if (sk.isReadable()) {

                    DatagramChannel datagramChannel = (DatagramChannel) sk

                         .channel();

                    datagramChannel.read(byteBuffer);

                    byteBuffer.flip();

                    // TODO 将报文转化为RUDP消息并调用RUDP协议处理器来处理

                    System.out.println(Charset.defaultCharset()

                         .decode(byteBuffer).toString());

                    byteBuffer.clear();

                    datagramChannel.write(Charset.defaultCharset()

                         .encode("Tell me your time"));

                 }

              }

           }

        } catch (Exception e) {

           e.printStackTrace();

        }

      }

   }

 

   public static void main(String[] args) {

      new UDPClient().start();

   }

}

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