Important topics to lean in java for Selenuim

OOPS Concept

Basic concept of Oops like
Class
Object
Inheritance
Polymorphism
Abstraction

List of keywords, Interface in Java.

Handle data types and usage of same.

Strings class

Control statements.

Looping statements.

String class, Wrapper classes, Array (2 D arrays)

Exception handling.

Collection framework (List, Set)

File handling.

Packages and Eclipse usages.