JAVA NIO 입문 실례

package com.liuc.io;

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.nio.charset.Charset;
import java.util.Iterator;
import java.util.Set;

import org.apache.log4j.Logger;

public class NIOServer extends Thread {
	private Logger log=Logger.getLogger(NIOServer.class);
	private boolean stop=false;
	private String ip="localhost";
	private int port=9999;
	private Selector selector;
	private ByteBuffer buffer=ByteBuffer.allocate(1024);
	private Charset gbkCharset = Charset.forName( "GB2312" );  
	public NIOServer() {
		try {
			selector=Selector.open();
			ServerSocketChannel ssc=ServerSocketChannel.open();
			InetSocketAddress address=new InetSocketAddress(ip, port);
			//ServerSocket  IP
			ssc.socket().bind(address);
			//        
			ssc.configureBlocking(false);
			//      
			ssc.register(selector,SelectionKey.OP_ACCEPT);	
			System.out.println("Listen to port:"+port);
		} catch (IOException e) {
			log.error(e);
		}
		
	}

	@Override
	public void run() {
		System.out.println("deal with request");
		while(!stop){
				String content="HelloWorld";
				try {
					int numKeys = selector.select();
					Set<SelectionKey> selectionKeys=selector.selectedKeys();
					Iterator<SelectionKey> iterator=selectionKeys.iterator();
					while (iterator.hasNext()) {
						 SelectionKey key = iterator.next();
						 iterator.remove();
						 dealRequest(key,content);
					}
				} catch (IOException e) {
					log.equals(e);
				}
				
		}
	}
	
	private void dealRequest(SelectionKey key,String contentToSend) {
		try {
			 
			 StringBuffer clientContent=new StringBuffer();
			  if(key.isAcceptable()){//                      。
				  ServerSocketChannel ssc=(ServerSocketChannel) key.channel();
				  SocketChannel sc=ssc.accept();
				  sc.configureBlocking(false);
				  sc.register(selector, SelectionKey. OP_READ);
			  }else if(key.isReadable()) {//                 。 
				  SocketChannel sc=(SocketChannel) key.channel();
				  while(true){//      
					  buffer.clear();
					  int r=sc.read(buffer);
					  buffer.flip();
					  byte[] temp=new byte[r];
					  if (r<=0) {
						break;
					  }
					  clientContent.append(gbkCharset.decode(buffer).toString());
					 
				  }
				  //       
				  String content=clientContent.toString();
				  String[] info=content.split(",");//       
				  System.out.println("         :"+content);

					  sc.register(selector, SelectionKey.OP_WRITE);
				  
			  }else if(key.isWritable()){//                 
				System.out.println("       "+contentToSend);
				buffer.clear();
				buffer.put(contentToSend.getBytes());
				buffer.flip();
				SocketChannel sc = (SocketChannel)key.channel();
				sc.write(buffer);
				buffer.flip();
				//          
				key.cancel();
                sc.close();
			}
			
		} catch (IOException e) {
			System.out.println(e);
			//       ，   Selector      
			key.cancel();
			if(key.channel() != null)
				try {
					key.channel().close();
					log.debug("the client socket is closed!");
					//System.out.println("the client socket is closed!");
				} catch (IOException e1) {
					e1.printStackTrace();
				}
		}
	}
		

	public static void main(String[] args){
		new NIOServer().start();
	}

}

package com.liuc.io;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;

public class NIOClient {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Socket socket=null;
		OutputStream outputStream=null;
		InputStream inputStream=null;
		try {
			socket=new Socket("localhost", 9999);
			outputStream=socket.getOutputStream();
			String sendContent="HelloWorld";
			outputStream.write(sendContent.getBytes());
			outputStream.flush();
			
			
			inputStream=socket.getInputStream();
			byte[] bytes=new byte[1024];
			int n=inputStream.read(bytes);
			System.out.println(new String(bytes));
			
			
		} catch (UnknownHostException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}finally{
			try {
					if(inputStream!=null){
						inputStream.close();
					}
					if (outputStream!=null) {
						outputStream.close();
					}
					if (socket!=null) {
						socket.close();
					}
			} catch (IOException e) {
				e.printStackTrace();
			}
			
		}
		

	}

}