When should I use static methods in Java?

You should use static methods in Java when the method performs a task that is not dependent on the state of an object instance. Static methods belong to the class rather than any specific instance and can be called directly using the class name.

When to Use Static Methods:

1. Utility or Helper Methods:
   Methods that perform a general operation or calculation, such as mathematical operations or string manipulations, can be made static. For example, Math.pow() or Arrays.sort().
2. Accessing Static Data:
   When a method operates only on static variables or constants in the class, it should be static. This avoids the need to create unnecessary object instances.
3. Performance Optimization:
   Since static methods are associated with the class and not with objects, they can sometimes be more efficient, as they don’t require object creation or instance method calls.
4. Global Logic:
   Static methods are often used for logic that is globally relevant across the application, such as logging frameworks or configuration loaders.
5. Factory Methods:
   In cases where an object creation process is simplified, a static factory method can be used instead of a constructor, e.g., Integer.valueOf().
6. Main Method:
   The public static void main(String[] args) method is a prime example. It is the entry point for Java applications and must be static because it is called without an instance.

When Not to Use Static Methods:

Avoid static methods if the logic depends on instance variables or requires polymorphic behavior, as static methods cannot be overridden by subclasses.