Question

My problem is this; I have to order a table of data. Each row of the table is an object (lets call it TableObject) stored in a List. Each column of data is a property of the class (usually a String).

I have to do the typical ordering of data when the user clicks on any column. So I thought about changing the List to a TreeSet and implementing Comparator in my TableObject.

The problem comes when I try to reorder the TreeSet. The compare is fairly easy at first (cheeking for exceptions in parseInt have been omitted):

   public int compare(TableObject to1, TableObject to2){
        TableObject t1 = to1;
        TableObject t2 = to2;

        int result = 1;

        if(Integer.parseInt(t1.getId()) == Integer.parseInt(t2.getId())){result=0;}
        if(Integer.parseInt(t1.getId()) < Integer.parseInt(t2.getId())){result=-1;}

        return result;

    }

But when I have to reorder by the text of the data or by other dozens of data that the TableObject has I have a problem.
I do not want to create dozens of compare functions, each for one. I prefer not to use a switch (or a chain of ifs) to decide how to compare the object.

Is there any way to do this in some way (like Reflexive), that doesn’t imply that I will write like hundreds of lines of nearly the same code?

Thanks for all!

Answer 1

Bean Comparator should work.

Using reflection the BeanComparator that will allow you to sort on any property that has a zero parameter method that returns the value of the property.

So basically you can sort on any property that has a "getter" method.