chatserver.java

本光盘包含了本书各章中出现的所有程序的源代码。 1. 如果是Java程序

package Server;

import java.nio.channels.Channels;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.channels.WritableByteChannel;
import java.net.ServerSocket;
import java.net.InetSocketAddress;
import java.nio.channels.Selector;
import java.nio.channels.SelectionKey;
import java.io.IOException;
import java.util.Iterator;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.nio.charset.*;
import java.nio.*;

public class ChatServer {
	 
	 private int port = 19;
	 private Selector selector;
	 private ServerSocketChannel ssc;
	 private ServerSocket server;
	 private InetSocketAddress address;
	 private ArrayList connectKey=new ArrayList();
	 
	 public ChatServer(){
	  //initServer  
	  try{
	   ssc=ServerSocketChannel.open();
	   server=ssc.socket();
	   address = new InetSocketAddress(port);
	   server.bind(address);
	   selector=Selector.open();
	   ssc.configureBlocking(false);
	   ssc.register(selector,SelectionKey.OP_ACCEPT);
	   System.out.println("============================================================");
	   System.out.println("=                                                                                                                                        =");
	   System.out.println("=                                                                                                                                        =");
	   System.out.println("=                                     version1.0                                                    =");
	   System.out.println("=                                                                                                                                        =");
	   System.out.println("=                                                                                                 =");
	   System.out.println("============================================================");   
	   System.out.println("Listening the port "+port+"...");  
	  }catch(IOException ex){
	   ex.printStackTrace();
	   System.exit(-1);
	  }
	 }
	 
	 public void startServer() throws IOException{
		 WritableByteChannel out=Channels.newChannel(System.out);
	  while(true){
	   int i=selector.select();
	   //System.out.print(i);
	   Iterator keys = selector.selectedKeys().iterator();
	   
	   while(keys.hasNext()){
	    SelectionKey key = (SelectionKey)keys.next();
	    keys.remove();
	    try{    
	     if(key.isAcceptable()){
	      ServerSocketChannel ssc=(ServerSocketChannel)key.channel();     
	      SocketChannel channel = ssc.accept();//return null if there's no request
	      System.out.println(channel+" has accepted");
	      channel.configureBlocking(false);
	      SelectionKey clientKey=channel.register(selector,SelectionKey.OP_READ);     
	     }//else 
	     if(key.isWritable()){
	      SocketChannel channel = (SocketChannel)key.channel();
	      ByteBuffer buffer = (ByteBuffer)key.attachment();
	      
	      if(buffer!=null){   
	       key.attach(null);//avoid the return twice
	       
	       //check info:the login or the message
	       //buffer.flip();
	       String checkBuffer = this.decode(buffer);
	       System.out.println("write:"+checkBuffer);
	       
	       if(checkBuffer.equals("LOGIN:OK")){
	        //return LOGIN:OK then add into the connectKey array!
	        System.out.println("ok"+buffer);
	        buffer.flip();
	        //while(buffer.hasRemaining()&channel.write(buffer)!=-1);
	        channel.write(buffer);
	        buffer.clear();
	        key.interestOps(SelectionKey.OP_READ|SelectionKey.OP_WRITE);      
	        connectKey.add(key);//add to the connectKey array
	        System.out.println("here");
	       }else if(checkBuffer.equals("LOGIN:ERROR")){
	        //return LOGIN:ERROR the client should close the channel
	        //warning:method:key.channel();
	        //Returns the channel for which this key was created.
	        // This method will continue to return the channel even after the key is cancelled.
	        while(buffer.hasRemaining()&channel.write(buffer)!=-1);
	        key.cancel();
	       }else //if(checkBuffer.indexOf("SENTO:")!=-1){
	       {	        
	        //return the message to everyone
	       // while(buffer.hasRemaining()&channel.write(buffer)!=-1);	  
	    	System.out.println("=============");    	
	        buffer.flip();
	        //out.write(buffer);
	        while(buffer.hasRemaining()&channel.write(buffer)!=-1);
	        buffer.clear();
	        //channel.write(buffer);
	        System.out.println("send over"); 
	       }
	      }
	     }//else 
	     if(key.isReadable()){
	      SocketChannel channel = (SocketChannel)key.channel();
	      ByteBuffer buffer=ByteBuffer.allocate(50);
	      System.out.println("read...");
	      
	      channel.read(buffer);
	 
	      buffer.flip();
	      String checkBuffer = this.decode(buffer);
	      System.out.println("read:"+checkBuffer);
	     
	      //while(buffer.hasRemaining()&&channel.read(buffer)!=-1);
	      
	      //check the buffer
	      //buffer.flip();
	      
	      //String checkBuffer = this.decode(buffer);
	     // System.out.println("read:"+checkBuffer);
	      
	     
	      if(checkBuffer.startsWith("LOGIN:")){
	       //get info of the user & pass then check for it,return feedback!
	       //the format is LOGIN:user&pass
	       int p1=checkBuffer.length();
	       int p2=checkBuffer.indexOf("&");
	       
	       String user=checkBuffer.substring(6,p2);
	       String pass=checkBuffer.substring(p2+1,p1);
	       System.out.println(user+pass);
	       
	       //todo check from the database!!!
	       //assume the user is legal
	       ByteBuffer feedback = ByteBuffer.allocate(20);
	       feedback=ByteBuffer.wrap("LOGIN:OK".getBytes());
	       key.interestOps(SelectionKey.OP_WRITE);
	       key.attach(feedback);      
	      }else if(checkBuffer.startsWith("SENTO:")){
	       String message = checkBuffer.substring(6);
	       System.out.println("sentto:"+message);
	       ByteBuffer buffer1 = ByteBuffer.allocate(50);
	       buffer1=ByteBuffer.wrap(message.getBytes());
	       Iterator it = connectKey.iterator();
	       //key.interestOps(SelectionKey.OP_WRITE);
	       while(it.hasNext()){
	        ((SelectionKey)it.next()).attach(buffer1.duplicate());
	       }
	       System.out.println("here1");
	       //for(int i=0;i<connectKey.add.;i++){
	        //connectKey[i].attach(buffer.duplicate());
	       //}
	      }
	     }
	    }catch(IOException ex){
	    	if(connectKey.contains(key)){
	    		System.out.println("has key");
	    		connectKey.remove(key);
	    	}
	     key.cancel();
	     //System.exit(-1);
	     
	     try{
	      key.channel().close();
	     }catch(IOException cex){
	     }
	    }
	   }
	  }
	 }
	 
	 public String decode(ByteBuffer buffer){
	  Charset charset=null;
	  CharsetDecoder decoder=null;
	  CharBuffer charBuffer=null;
	  try{
	   charset= Charset.forName("gb2312");
	    decoder= charset.newDecoder();
	    charBuffer= decoder.decode(buffer);
	   return charBuffer.toString();
	  }catch(Exception ex){
	   ex.printStackTrace();
	   return "";
	  }
	  
	 }
	 
	 public static void main(String []args){
	  ChatServer cs = new ChatServer();
	  try{
	   cs.startServer();
	  }catch(IOException ex){
	   ex.printStackTrace();
	   System.exit(-1);
	  }
	 }
	}