For what reasons is Java considered a programming language that does not fully comply with object-oriented principles?

Java is considered a language that does not fully adhere to the principles of object-oriented programming (OOP) for several reasons:

• Primitive data types (int, double, boolean, etc.) are not objects, which violates the idea that everything is an object.
• Lack of multiple inheritance of classes — Java supports only single inheritance, which limits the flexibility of OOP.
• Static methods and fields — they belong to the class, not the object, which contradicts the pure object model.
• Lack of operator overloading support — in pure OOP, operators should be methods of objects.

Thus, Java is a language with strong OOP support but with some compromises for practicality and performance.