Java – find duplicate entries in the collection

Is there a tool or library that can find duplicate entries in the collection according to specific standards that can be implemented?

In order to make myself clear: I want to compare items with each other according to specific criteria So I think a predicate that only returns true or false is not enough

I can't use equality

Solution

This depends on the semantics of the standard:

If your standards are always the same for a given class and are inherent in the underlying concepts, you should implement equals and hashcode and use a collection

If your criteria depend on the context, org apache. commons. collections. CollectionUtils. Select (Java. Util. Collection, org. Apache. Commons. Collections. Predict) may be your correct solution