Question

How to sort list based on its element value?

In my unit test class, I am receiving list which is in sorted form based on one of its element’s value {sortOrder and it has value 1, 2 and 3} now I am comparing returnedList with expectedList to make sure that both list are same and have same elements in same order.

Example of my return and expected list:

expected List = [Code: ANALYST, SortOrder: 2, Code: STREET, SortOrder: 1]

and returned List = [Code: STREET, SortOrder: 1, Code: ANALYST, SortOrder: 2]

So how can i sort the list on SortOrder so that my expected list becomes:

expected List = [Code: STREET, SortOrder: 1, Code: ANALYST, SortOrder: 2]

I cannot use any libraries and this question is related to Compare List Question, any suggestions?

Answer 1

use this:

 public static void sort(List list, Comparator c)

So do something like this:

Collections.sort(myList, myComparator)

myComparator is an interface for which you only have to implement one method which is compare:

public int compare(Object o1, Object o2)

So you can do this with an anonymous inner class:

Collections.sort(myList, new Comparator<MyType>(){ 
    public int compare(MyType o1, MyType o2) { 
        //My implementation
    }
 });

For information on how to implement the compare method take a look at the documentation here:

Comparator