Class file is being deleted on compiling

Question

Hi,
I am new to this forum. I am having problem compiling my code. I have imported a package and when I compile the source code the class file from the package gets deleted and compiler gives me error that noClassDeff found.Could anyone please help me. I would highly appreciate it.
I have to submit this assignment in 3 days time.

Answer 1

Thanks for replying
the code is:
import aston.net.DatagramMessage;
import java.io.*;
import java.util.*;
import java.net.*;
public class TCPclient
public static void main(String args[])
try
{I
netAddress duke = InetAddress.getByName("127.0.0.1");
DatagramMessage one=new DatagramMessage("here",duke,9001);
TCPclient.sendString("127.0.0.1", 9001);
catch (UnknownHostException ex) {
System.err.println(ex);
the error i get is:
Exception in thread "main" java.lang.NoClassDefFoundError: aston/net/DatagramMessage
     at TCPclient.main(TCPclient.java:81)
the code for DataMessage is:
package aston.net;
import java.net.InetAddress;
* A class to use with MyServerDatagramSocket for
* returning a message and the sender's address
* @author M. L. Liu
public class DatagramMessage{
private String message;
private InetAddress senderAddress;
private int senderPort;
public DatagramMessage(String message, InetAddress addr, int port) {
this.message = message;
this.senderAddress = addr;
this.senderPort = port;
public String getMessage( ) {
return this.message;
public InetAddress getAddress( ) {
return this.senderAddress;
public int getPort( ) {
return this.senderPort;
} // end class
The DatagramMessage compiles and Class file is created but when i use it in TCPClient the class file gets deleted.
I am using JBuilder and OS is windows XP