In object-oriented programming, a wrapper class is a class that encapsulates types, so that those types can be used to create object instances and methods in another class that needs those types. So a primitive wrapper class is a wrapper class that encapsulates, hides or wraps data types from the eight primitive data types, so that these can be used to create instantiated objects with methods in another class or in other classes. The primitive wrapper classes are found in the Java API.

Primitive wrapper classes are used to create an Object that needs to represent primitive types in Collection classes (i.e., in the Java API), in the java.util package and in the java.lang.reflect reflection package. Collection classes are Java API-defined classes that can store objects in a manner similar to how data structures like arrays store primitive data types like int, double, long or char, etc., but arrays store primitive data types while collections actually store objects.

The primitive wrapper classes and their corresponding primitive types are: