How to remove duplicate objects in a List without equals/hashcode?

Question

I have to remove duplicated objects in a List. It is a List from the object Blog that looks like this:

public class Blog {
    private String title;
    priv         


        

Answer 1

1. override hashCode() and equals(..) using those 4 fields
2. use new HashSet(blogList) - this will give you a Set which has no duplicates by definition

Update: Since you can't change the class, here's an O(n^2) solution:

• create a new list
• iterate the first list
• in an inner loop iterate the second list and verify if it has an element with the same fields

You can make this more efficient if you provide a HashSet data structure with externalized hashCode() and equals(..) methods.