CODEWITHSUNDEEP
javacollectionshashset
Akhil K Nambiar
Akhil K Nambiar

Reputation: 3975

Increase speed of HashSet

I have a List of objects with unique identifier (id), fetched from a DB. For a particular scenario I have to remove duplicates. For that purpose, I am storing it in a HashSet. However, that process takes some time.

I wanted to know how this HashSet identifies duplicates. toString function has been overridden. Is there any other function or something that I should override to help speedup the HashSet function?

Will hash function overriding be of any help?

Upvotes: 0

Views: 79

Answers (1)

Eran
Eran

Reputation: 394136

You should be overriding the hashCode and equals methods. Those are the methods used to locate a key in the HashSet/HashMap.

The HashSet identifies duplicates by first calculating the hashCode of the object it is searching for, and then iterating over all the objects in the HashSet that share this hashCode and comparing them to the searched object with equals, until a match is found.

Upvotes: 2

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