how to add Arraylist filter for a jsp page showing results from a servlet-Arraylist

[alok_sharma]

hello sir/mam, in my project i have an arraylist showing results in a jsp page table of given contents of database, i want to add a filter to it to show only the matched contents from list,

the table which is coming out is as:
student_id class_id student_name
1x0001        10         Ashish
1x2001        11         Anurag
1x2002        11         Arpit
1x0001        10         Alok

.............going on...

but i want the result to display page only for class_id::11 and remove other results how to do that?

and from that i want result filtered as this

the table which is filter will show as:
student_id class_id student_name
1x2001        11         Anurag
1x2002        11         Arpit

.............going on...

[Tolls]

Change the query you're using to retrieve this stuff form the database?

[alok_sharma]

easy to say hard to implement, the database query is in nests of joins and union thus its much harder to implement and also i am using getters and setters and the same query on many places where filter is not needed thus i asked for arraylist filtering ;)

[Tolls]

Nope.
You filter in the query.
You must be able to attach a filter to the existing query...joins and unions and all that are irrelevant if you still need to filter the result. Java will be so much slower than than the db at doing this.

[alok_sharma]

yes i know but still i will emphasize on java, as changing my query will make my project upside down.

[Tolls]

Sounds like it's already upside down...anyway, iterate over the List calling the iterators remove method on the ones you don't want.

[alok_sharma]

i am not using iterators in my code so should i need to re-write it with iterators

[Tolls]

Because an iterator is the correct way for doing this.
You have an ArrayList (according to your first post), so getting an iterator is easy. As for re-writing, well presumably you have to rework some of it because you need to do this filtering?