NIO部分:DatagramChannel实例

package com.test.socket;

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;

public class DatagramChannelTestMain {
	private static final int port = 30008;
	private static final int TIMEOUT = 3000;

	/**
	 * @param args
	 */
	public static void main(String[] args) throws Exception {
		// TODO Auto-generated method stub
		Thread serverThread = new ServerThread();
		serverThread.start();
		Thread clientThread = new ClientThread();
		clientThread.start();
		Thread.sleep(2000);
	}

	static class ServerThread extends Thread {

		@Override
		public void run() {
			DatagramChannel channel = null;
			try {
				channel = DatagramChannel.open();
				channel.configureBlocking(false);
				DatagramSocket socket = channel.socket();
				socket.bind(new InetSocketAddress(port));
				Selector selector = Selector.open();
				channel.register(selector, SelectionKey.OP_READ);
				while(selector.isOpen()){
					System.out.println("S....!!!");
					if(selector.select() == 0){//select must be
						System.out.println("s....");
						Thread.sleep(2000);
						continue;
					}
					Iterator<SelectionKey> it = selector.selectedKeys().iterator();
					while(it.hasNext()){
						SelectionKey key = it.next();
						if(key.isValid() && key.isReadable()){
							read(key);
						}
					}
				}
			}catch(Exception e){
				e.printStackTrace();
			}finally{
				if(channel != null){
					try{
						channel.close();
					}catch (Exception ex) {
						ex.printStackTrace();
					}
				}
			}
		}

		private void read(SelectionKey key) throws Exception {
			DatagramChannel channel = (DatagramChannel)key.channel();
			System.out.println("channel" + channel.toString());
			ByteBuffer byteBuffer = ByteBuffer.allocate(256);
			InetSocketAddress address = (InetSocketAddress)channel.receive(byteBuffer);
			if(address == null){
				System.out.println(".....");
			}else{
				System.out.println(address.getAddress() + "//" + address.getPort());
			}
			byteBuffer.flip();
			Charset charset = Charset.defaultCharset();
			CharBuffer charBuffer = charset.decode(byteBuffer);
			System.out.println("Server read:" + charBuffer.toString());
			//if write,please here.
			byteBuffer = charset.encode("this is server sent!");
			channel.send(byteBuffer, address);
			key.interestOps(SelectionKey.OP_READ);
		}

	}

	static class ClientThread extends Thread {
		@Override
		public void run() {
			DatagramChannel channel = null;
			try {
				channel = DatagramChannel.open();
				channel.configureBlocking(false);
				channel.connect(new InetSocketAddress("10.12.124.19",port));
				while(!channel.isConnected()){
					System.out.println("....");
				}
				Selector selector = Selector.open();
				channel.register(selector, SelectionKey.OP_WRITE);
				while(selector.isOpen()){
					if(selector.select() == 0){
						Thread.sleep(2000);
						continue;
					}
					Iterator<SelectionKey> it = selector.selectedKeys().iterator();
					while(it.hasNext()){
						SelectionKey key = it.next();
						if(key.isValid() && key.isWritable()){
							write(key);
						}else if(key.isReadable()){
							read(key);
						}
					}
				}
			}catch (Exception e) {
				e.printStackTrace();
			}finally{
				if(channel != null){
					try{
						channel.close();
					}catch(Exception ex){
						ex.printStackTrace();
					}
				}
			}
		}
		
		private void write(SelectionKey key) throws Exception{
			DatagramChannel channel = (DatagramChannel)key.channel();
			Charset charset = Charset.defaultCharset();
			ByteBuffer byteBuffer = charset.encode("this is client sent!");
			System.out.println("p:" + byteBuffer.position() + "//l:" + byteBuffer.limit());
			while(byteBuffer.hasRemaining()){
				channel.write(byteBuffer);
			}
			System.out.println("cw ok!");
			key.interestOps(SelectionKey.OP_READ);
		}
		
		private void read(SelectionKey key) throws Exception{
			DatagramChannel channel = (DatagramChannel)key.channel();
			Charset charset = Charset.defaultCharset();
//			ByteBuffer byteBuffer = charset.encode("this is client sent!");
//			System.out.println("p:" + byteBuffer.position() + "//l:" + byteBuffer.limit());
			ByteBuffer byteBuffer = ByteBuffer.allocate(256);
			while(channel.read(byteBuffer) > 0){
				//
			}
			byteBuffer.flip();
			CharBuffer charBuffer = charset.decode(byteBuffer);
			System.out.println("Client read:" + charBuffer.toString());
			key.interestOps(SelectionKey.OP_WRITE);
		}
	}
}