How to implement column header sort

Question

Hi all,
Does anyone know how to configure Oracle 9i AS Portal Release 2 column header sort.
In Portal, Oracle has setup the IDE to sort your columns using arrow keys in the
column headers. I would like to do the same thing without using the Custom Form.
TIA,
Daniel N

Answer 1

I would suggest using the built in Collections framework for sorting.
have class A implement the Comparable interface then implement the compareTo method as follows:
public int compareTo(Object o) {
    A a = (A)o;  // <-- may cause ClassCastException if (o instanceof A) != true, but that should not be a problem.
    int value = attr1.compareTo(a.attr1);
    if (value != 0) return value;
    value = attr2.compareTo(a.attr2);
    if (value != 0) return value;
    value = a.attr3.compareTo(attr3);  //Notice I switched a.attr3 and attr3 for desc
    return value;
}That should do it for you.
Now put everything into an instance of java.util.List and pass that to java.util.Collections.sort(java.util.List);
If you didn't create class A, and therefore can't add a method to it, then implement a Comparator. The idea is the same, just look at the java.util.Comparator API and use java.util.Collection.sort(java.util.List, java.util.Comparator) method to sort;