PROBLEM
By default, IntelliJ IDEA generates mutable classes and fields.
One of the steps to achieve immutability is to make all classes and fields to be final.
SOLUTION
Making Fields Final
Go to Preferences… -> Code Style -> Java -> Code Generation tab
Under Final Modifier, check both Make generated local variables final and Make generated parameters final.
Making Classes Final
Go to Preferences… -> File and Code Templates -> Templates tab
Select Class and add final.
Leave a Reply