Find Form bean changes in Action

Question

I have a requirement in struts 1.2 framework where i have 50 to 60 fields in my form in which i have to update only 3Fields(which are changed by the user) so when i submit the form only these 3Fields needs to be updated in the database.
How can i identify the 3 changed/modified fields out of 50 fields in the struts ActionForm.
Your suggestions are very mush appreciated.

Answer 1

There is no out of the box approach to achieve this. If your application collects form data into a DTO object, you could probably hold that object in session and compare it with the form object for differences.
Another option would be to maintain a boolean field (for each form field) which toggles its state when the form field is changed.
  public class <XXX>Form extends ActionForm{
     private String xxxField;
     private boolean xxxFieldIsDirty;
     public void setXXXField(String val){
       this.xxxField = val;
       xxxFieldIsDirty = true;
   .....You will have to then write some reflection code that returns you the 'dirty' fields of the form. You will also have to reset all the isDirty fields to false before the response goes out.