NIO demo:EchoServer

客戶端可以用telnet工具,退出命令爲 exit 。

以下爲Echo服務器端:

package org.sl.nio;

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.Iterator;
import java.util.Set;

public class EchoServer1 {
	static private int bufferSize = 1024*2;
	private int servicePort = 7777;
	private Selector selector = null; 
	private byte[] welcomeMsg = null;	
	private ByteBuffer echo = null;
	private ByteBuffer bye = null;
	
	public EchoServer1(){
		this(7777);
	}
	
	public EchoServer1(int port){
		this.servicePort = port;
	}
	
	public void initialize() throws IOException{
		ServerSocketChannel server = null;
		
		server = ServerSocketChannel.open();
		server.configureBlocking(false);
		server.socket().bind(new InetSocketAddress(servicePort), bufferSize);
		
		selector = Selector.open();
		server.register(selector, SelectionKey.OP_ACCEPT);
		
		String msg 	= "Welcome to MyOS(v1.0).\r\n";					
		welcomeMsg = msg.getBytes();
		echo = ByteBuffer.wrap("$ ".getBytes());
		bye = ByteBuffer.wrap("bye.\r\n".getBytes());
	}
	
	public void startup() throws IOException{
		System.out.println("服務啓動,正在監聽端口 "+servicePort);
		Set<SelectionKey> keys = null;
		Iterator<SelectionKey> iter = null;
		SelectionKey key = null;
		
		while(selector.select() > 0){
			keys = selector.selectedKeys();
			iter = keys.iterator();	
			
			while(iter.hasNext()){
				key = iter.next();
				iter.remove();
				
				try{
					if(key.isAcceptable()){
						accept(key);						
						continue;
					}
					
					if(key.isReadable()){
						receive(key);						
						continue;
					}
					
					if(key.isWritable()){
						if(send(key)){
							try{
								if(null!=key) key.cancel();
							}catch(Exception e){						
							}
							
							try{
								if(null!=key) key.channel().close();
							}catch(Exception e){						
							}
							
							break;
						}		
						continue;
					}
				}catch(Exception ex){
					ex.printStackTrace();
					
					try{
						if(null!=key) key.cancel();
					}catch(Exception e){						
					}
					
					try{
						if(null!=key) key.channel().close();
					}catch(Exception e){						
					}
				}
			}
		}
	}
	
	void accept(SelectionKey key) throws IOException{
		ServerSocketChannel ssc = (ServerSocketChannel) key.channel();
		SocketChannel sc = ssc.accept();
		sc.configureBlocking(false);
		System.out.println("有新客戶連接 "+ sc.socket().getInetAddress()+":"+sc.socket().getPort());
		
		ByteBuffer buffer = ByteBuffer.allocate(bufferSize);		
		buffer.position(0);
		buffer.put(welcomeMsg);
		sc.register(selector, SelectionKey.OP_READ | SelectionKey.OP_WRITE, buffer);
	}
	
	/**
	 * 接收數據
	 * @param key	
	 * @throws IOException
	 */
	void receive(SelectionKey key) throws IOException{
		SocketChannel sc = (SocketChannel) key.channel();
		ByteBuffer buffer = (ByteBuffer) key.attachment();
		ByteBuffer readBuffer = ByteBuffer.allocate(128);
//		byte[] cmd = null;
//		String cmdStr = null;
		int readLen = sc.read(readBuffer);
		readBuffer.flip();
		
//		readBuffer.position(0);
//		if(readBuffer.limit()<16){
//			cmd = new byte[16];
//			readBuffer.get(cmd, 0, readLen);
//			cmdStr = new String(cmd, 0, readLen);
//			
//			if(cmdStr.startsWith("exit")){
//				System.out.println("exit.");
//				buffer.put("bye.\r\n".getBytes());
//				return true;
//			}
//		}
		
		readBuffer.position(0);
		buffer.put(readBuffer);		
//		byte[] bys = new byte[128];
//		readBuffer.get(bys, 0, readLen);		
//		System.out.println("|"+new String(bys,0,readLen)+"|");		
		
//		buffer.flip();
//		byte[] bys = new byte[1024];
//		int limit = buffer.limit();
//		buffer.get(bys,0,limit);
//		System.out.println("|"+new String(bys,0,limit)+"|");
//		buffer.limit(buffer.capacity());
	}
		
	boolean send(SelectionKey key) throws IOException{
		SocketChannel sc = (SocketChannel) key.channel();		
		ByteBuffer buffer = (ByteBuffer) key.attachment();
//		ByteBuffer sendBuffer = ByteBuffer.wrap("echo:".getBytes());
		ByteBuffer sendBuffer1 = null;
//		byte[] bys = new byte[buffer.capacity()];
		byte[] bys = null;
		String cmd = null;
		
//		buffer.flip();
		int bl = buffer.position();
				
		if(bl>0){
			byte end = buffer.get(bl-1);
			
			if(end == '\n'){				
//				bys[0] = '{';
//				buffer.get(bys, 1, bl-1);
//				bys[bl] = '}';
//				bys[bl+1] = '\n';
//				String str = new String(bys,0,bl+2);
//				System.out.println(str);
				
//				sendBuffer1 = ByteBuffer.wrap(buffer.);			
//				buffer.position(0);
								
				buffer.flip();
				buffer.position(0);
				
				bys = new byte[buffer.limit()];
				buffer.get(bys, 0, bl);
				cmd = new String(bys,0,bl);
				
				if(cmd.startsWith("exit")){
					sc.write(bye);
					return true;
				}				
				buffer.position(0);
//				sendBuffer1 = buffer.slice();
				sc.write(buffer);
				
				echo.position(0);
				sc.write(echo);
//				
//				sendBuffer1.clear();
				buffer.clear();
			}
		}
		buffer.limit(buffer.capacity());
		return false;
		//byte end = buffer.get(-1);
	}	
	
	public void setBufferSize(int _bufferSize){
		bufferSize = _bufferSize;
	}
}

啓動測試類:

package org.sl.test0;

import java.io.IOException;

import org.sl.nio.EchoServer;
import org.sl.nio.EchoServer1;

public class T1 {
	public static void main(String[] args){
		t2();
//		t1();
	}
	
	static void t2(){		
		try {
			int port = 7777;
			EchoServer1 server = new EchoServer1(7777);
			server.initialize();
			
			server.startup();
			
		} catch (IOException e) {		
			e.printStackTrace();
		}
		
	}
}