boolean is a primitive data type in Java and primitive data types can not be null like other primitives int, float etc, they should be containing default values if not assigned.
In Java, only objects can assigned to null, it means the corresponding object has no reference and so does not contain any representation in memory.
Hence If you want to work with object as null , you should be using Boolean class which wraps a primitive boolean type value inside its object.
These are called wrapper classes in Java
For Example:
Boolean bool = readValue(...); // Read Your Value
if (bool == null) { do This ...}