Date problems - Strings and math

Good day all
I'm using the Sun JDK1.3.0_02 on Windows 2000. I need to:
1) get the current date in the format dd/mm/yyyy (call this the deal_date)
2) add 30 days to the above (call the result expiry_date)
3) convert both deal_date and expiry_date to Strings
4) when calling expiry_date from a database, compare it to the current (system) date to see if the difference is greater than 30 days.
Please could somone give me the cleanest possible method of doing this. I have grappled with the classes Calendar, GregorianCalendar, Date and DateFormat until my head hurts. I would prefer to use the standard classes found in the JDK rather than adding additional classes.
many thanks.
Clive

Hi Clive,
Try the following code. It might be what you are looking for.

import java.util.*;
import java.text.*;
public class A
{
  public static void expired( GregorianCalendar dealGC )
  {
    //
    // Figure out the date 30 days ago.
    //
    GregorianCalendar expireGC = new GregorianCalendar();
    expireGC.add( Calendar.DATE, -30 );
    if( dealGC.before( expireGC ) )
    {
      System.out.println( "Date: " + dealGC.getTime() + " has expired!" );
    }
    else
    {
      System.out.println( "Date: " + dealGC.getTime() + " still good." );
    }
  }
  public static void main( String[] args )
  {
    //
    // Start with todays date in a calendar variable.
    //
    GregorianCalendar dealGC = new GregorianCalendar();
    //
    // Add 30 days to the dealGC to get the expireGC
    //
    GregorianCalendar expireGC = new GregorianCalendar();
    expireGC.add( Calendar.DATE, 30 );
    //
    // Create date formatter to get dd/mm/yyyy.
    //
    SimpleDateFormat sdf = new SimpleDateFormat( "dd/mm/yyyy" );
    System.out.println( "Deal Date: " + dealGC.getTime() );
    System.out.println( "Expire Date: " + expireGC.getTime() );
    //
    // Now suppose we start with dealGC and need to see if it has expired.
    // Lets say we made the deal 28 days ago.
    //
    dealGC = new GregorianCalendar();
    dealGC.add( Calendar.DATE, -28 );
    expired( dealGC );
    //
    // Now lets say we made the deal 31 days ago.
    //
    dealGC.add( Calendar.DATE, -3 );
    expired( dealGC );
  }
}

Enjoy,
Manfred.

Thanks very much Manfred, this is just fine. Thanks also to JavaRanch for a really useful site

Clive