integer vs int

use int if you can, if can be null or used as an Object e.g. Generics, use Integer

• Prefer int for performance reasons
• Methods that take objects (including generic types like List<T>) will implicitly require the use of Integer
• Use of Integer is relatively cheap for low values (-128 to

127. because of interning - use Integer.valueOf(int) and not new Integer(int)

• Do not use  == or != with Integer types
• Consider using Integer when you need to represent the absence of a value (null)
• Beware unboxing Integer values to int with null values