sort a map or arraylist according to the value of the object inside

[Imesh Damith]

I have 400 Employee objects in a hashmap. This employee object contains salary detail.
The Employe objects are now in the hashMap. i want to put these objects in to a array list which is sorted to lowest salary object to come first.

how do i sort the arraylist to come lowest salary first.

[pete stein]

Collections.sort(myArrayList) will work, but first you have to either have your Employee class implement the Comparable<Employee> interface. Either that or use a Comparator object.

[Imesh Damith]

how does it know to sort to salary? Employee object contains firstname, lastname, TP etc.

[pete stein]

Imesh Damith wrote:how does it know to sort to salary? Employee object contains firstname, lastname, TP etc.

If implementing a Comparable interface, then you class will know how to sort because you will place the sorting logic in the compareTo(....) method. Please google for a tutorial on this as I bet if you read one or two of them, it will become all clear.

[Charith De Silva]

This would do your job.

BeanComparator beanComparator = new BeanComparator(colomn);
Collections.sort(arraylist,beanComparator);

[Rob Spoor]

Only if you have the BeanComparator class in your class path. I certainly don't. Where is it from?

[Imesh Damith]

Thanks charith, this is really working.