describe this program code by code ....

Code Java:

---

import java.util.*;
import java.io.*;
class StudAccount {
public static void main (String[] args)throws IOException {
 
 TreeSet currAccounts = new TreeSet();
 TreeSet oldAccounts =  new TreeSet();
 TreeSet gradAccounts = new TreeSet();
 TreeSet newAccounts =  new TreeSet();
       try
       {
   readAccounts
   ("curraccounts.txt", currAccounts);
   readAccounts
   ("oldaccounts.txt", oldAccounts);
 
   gradAccounts.addAll(oldAccounts);
   gradAccounts.removeAll(currAccounts);
   newAccounts.addAll(currAccounts);
   newAccounts.removeAll(oldAccounts);
       }
  catch(IOException ioe)
   {
   System.out.println("Cannot open file");
   System.exit(1);
   }
   FileOutputStream out1;
               PrintStream p1;
   FileOutputStream out2;
               PrintStream p2;
               try
                {
   out1 = new FileOutputStream("gradaccounts.txt");
   out2 = new FileOutputStream("newaccounts.txt");
 
     p1 = new PrintStream( out1 );
     p2 = new PrintStream( out2 );
                       p1.println (gradAccounts);
     p2.println (newAccounts);
                       p1.close();
                       p2.close();
                }
               catch (Exception e)
                 {
                       System.err.println ("Error writing to file");
                 }
 System.out.println("The people who have graduated are" + gradAccounts);
 System.out.println("The people who are new" + newAccounts);
    }
public static void readAccounts(String filename, TreeSet Accounts)
   throws IOException
     {
 Scanner sc = new Scanner(new FileReader(filename));
   String id = null;
   String name = null;
   String cgpa = null;
 
 while (sc.hasNext())
    {
id = sc.next();
name = sc.next();
cgpa = sc.next();
   Accounts.add(name);
        }
        }
}

---

Please see the link in my signature entitled 'getting help'

Edit: and that link applies to every one of your other posts as well. I would also encourage you to read the following: http://catb.org/~esr/faqs/smart-questions.html

Well it seems you don't know the Rules of this forum!