在faq里的 ----------------------------------------
用httpurlconnection好了,因为都是http的连接。  
在httpurlconnection里可以给servlet传递参数,也可以接收servlet发送出来的符合http协议的data,httpurlconnection有相应的方法分析http-head,不过http-body,也就是html就需要自己来分析。  
还有就是applet只可以与它被下载的服务器的servlet通信。  
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ServerSocket  serverSocket  =  null;  
       private  DataOutputStream  outStream  =  null;    
       private  DataInputStream  inStream  =  null;              
               try  {  
                       serverSocket  =  new  ServerSocket(port);  
       
                       socket  =  serverSocket.accept();  
 
                       //initialize  socket,outStream  
                       inStream  =  new  DataInputStream(new  BufferedInputStream(socket.getInputStream()));  
                       outStream  =  new  DataOutputStream(new  BufferedOutputStream(socket.getOutputStream()));  
 
                       //receive  Msg  from  client  
                       int  len  =  inStream.readInt();  
                       //if(len  <=  0)  {  
                               //return;  
                       //}  
                       byte[]  readBytes=new  byte[len];  
                       int  i=0,j=len;  
                       //获取返回信息  
                       while(j>0)  {  
                                       int  k=inStream.read(readBytes,i,j);  
                                       i=i+k;  
                                       j=j-k;  
                       }  
                       String  clientMsg  =  new  String(readBytes,0,len,"GB2312");  
 
                       //send  Ack  to  client  
                       byte[]  sendBytes  =  null;  
 
                               sendBytes  =  "<Ack>error</Ack>".getBytes("GB2312");  
                               outStream.writeInt(sendBytes.length);  
                               outStream.write(sendBytes);  
                               outStream.flush();  
                               outStream.close();  
                               socket.close();  
               }  
               catch(Exception  e)  {  
                       if(socket  !=  null)  {  
                               socket.close();  
                       }  
                       if(outStream  !=  null)  {  
                               outStream.close();  
                       }  
                       if(inStream  !=  null)  {  
                               inStream.close();  
                       }  
               }  
我不是高手,别人的代码借过来用一下,共同学习。