ArrayList sorting on the basis of object property [duplicate]

Answer 1

You need to write a Comparator.

class EmployeeAgeComparator implements Comparator
{
    @Override
    public int compare(Employee e1, Employee e2)
    {
        if (e1.getAge() > e2.getAge())
        {
            return -1;
        } 
        else if (e1.getAge() < e2.getAge())
        {
            return 1;
        }
        return 0;
    }
}

Then use Collections.sort method like this.

Collections.sort(empList, new EmployeeAgeComparator());

Hope this helps.