import java.io.*;    import java.net.*;    public class EchoTest{    public static void main(String[] args){     try{     Socket echoSocket=new Socket("hust",8);     OutputStream os=echoSocket.getOutputStream();     DataInputStream is=new DataInputStream     (echoSocket.getInputStream)());                 int c;    String responseLine;    while((c=System.in.read())!=-1){       os.write((byte)c);       if(c==‘\n’){     os.flush();     responseLine=is.readLine();     System.out.println("echo:"+responseLine);    }      }       os.close();       is.close();       echoSocket.close();      }catch(Exception e){    System.err.println("Exception:"+e);      }     }                                  }