This is about serialization and deserialization in java.

This week, you'll be writing objects to a file and reading objects from a file. The ReadContactFile code has been done for you, and must be used as is. This file is attached to the assignment link. Your job is to create the files that can use this ReadContactFile code.

• Create a class Contact, with an integer contact ID, a first name, a last name, and a phone number. (If you look the ReadContactFile code, you'll see that your class has to have a specific method to output the information)
  
• Create the code to write out at least 4 contacts to a file. File name should be the same as the ReadContactFile code file name.

Time to put it all together. Make sure the program works, and include the three files; the object file, the write file, and the data file. Do not include the ReadContactFile code, as I'll insert the pre-written one!
ReadContactFile is as follows:

import java.io.*;
public class ReadContactFile{

 public static void main(String [] args) throws IOException, ClassNotFoundException {
  
  ObjectInputStream in = new ObjectInputStream(new FileInputStream("Contacts.dat"));
  Contact con;
  
  try {
   while(true) {
    con = (Contact)in.readObject();
    con.display();
   }
 }
 catch(EOFException e) {
  in.close();
 }
   }
   
}

I coded Contact.java as follows: