Is it possible to override static method in java

Though it is certainly possible, does it not defeat the whole purpose of static modifier. Please correct me if I am wrong, however I felt compelled to post my query.

Regards, Ravi Prakash. Post a Comment. Can a static method be overridden in Java, or can you override and overload static method in Java , is a common Java interview questions mostly asked to 2 years experienced Java programmers. The answer is, No, you can not override static method in Java , though you can declare a method with the same signature in a subclass.

It won't be overridden in the exact sense, instead, that is called method hiding. But at the same time, you can overload static methods in Java, there is nothing wrong with declaring static methods with the same name, but different arguments.

Some time interviewer also ask, Why you can not override static methods in Java? The answer to this question lies in the time of resolution. As I said in the difference between static and dynamic binding , static methods are bonded during compile time using Type of reference variable, and not Object. If you have using IDE like Netbeans and Eclipse, and If you try to access static methods using an object, you will see warnings. As per Java coding convention, static methods should be accessed by class name rather than an object.

In short, a static method can be overloaded, but can not be overridden in Java. If you declare, another static method with same signature in derived class than the static method of superclass will be hidden, and any call to that static method in subclass will go to static method declared in that class itself.

This is known as method hiding in Java. Let's see an example of trying to override a static method. In this Java The program, we have two classes Parent and Child , both have name method which is static.

Now, As per rules of method overriding , if a method is overridden than a call is resolved by the type of object during runtime. This means, in our test class StaticOverrideTest , p. This happens, because static methods are resolved or bonded during compile time , and only information that is available, and used by the compiler is a type of reference variable.

Since p was a reference variable of the Parent type, the name method from the Parent class was called. Now, In order to prove that static method can be hidden, if we call Child. This means static methods can not be overridden in Java, they can only be hidden. This also answers, Why the static method can not be overridden in Java , because they are resolved during compile time. We cannot overload two methods in Java if they differ only by static keyword number of parameters and types of parameters is the same.

See the following Java program for example. Can we Override static methods in java? If a derived class defines a static method with the same signature as a static method in the base class, the method in the derived class is hidden by the method in the base class.

For example, the following program has two compiler errors. Such overloaded methods neither hide nor override the superclass methods — they are new methods, unique to the subclass. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

Skip to content. Change Language. Related Articles. Consider if the instance is passed as a parameter. Then you are saying that the runtime instance should dictate which static method is called. That basically makes a whole separate hierarchy parallel to the existing instance one. Now what if a subclass defines the same method signature as non-static? I think that the rules would make things quite complicated.

It is precisely these kinds of language complications that Java tries to avoid. Yishai: RE "Runtime instance dictate which static method is called": Exactly. I don't see why you can't do anything with a static that you can do with a virtual. Why aren't statics included in the same hierarchy? I think Jay has a point - it surprised me too when I discovered that statics could not be overridden. If I subsequently add someStatic to B, the calling code still invokes A. Also it surprised me that bInstance.

Show 28 more comments. The short answer is: it is entirely possible, but Java doesn't do it. Here is some code which illustrates the current state of affairs in Java: File Base.

Called static Base method. Called non-static Child method. Object: static type Child; runtime type Child. Called static Child method.

Class: Child static call. Class: Base static call. Non-static calls own static. Non-static calls overridden? Here, the only cases which might be a surprise and which the question is about appear to be the first case: "The run-time type is not used to determine which static methods are called, even when called with an object instance obj.

Calling from within an object method Object method calls are resolved using the run-time type, but static class method calls are resolved using the compile-time declared type.

Changing the rules To change these rules, so that the last call in the example called Child. Other considerations If we changed this behaviour and made static calls potentially dynamically non-local , we would probably want to revisit the meaning of final , private and protected as qualifiers on static methods of a class.

Steve Powell Steve Powell This is routinely touted as a positive feature for ordinary virtual functions, not a problem. Add a comment. Despite Java doesn't allow you to override static methods by default, if you look thoroughly through documentation of Class and Method classes in Java, you can still find a way to emulate static methods overriding by following workaround: import java.

InvocationTargetException; import java. Patlatus Patlatus 9 9 silver badges 19 19 bronze badges. This answer is the biggest hack I've seen so far across all Java topics. Was fun to read it still : — Andrejs. EDIT You can overload static method, that's ok.

Lawrence Dol Even many modern languages like Ruby have class-methods and allow overriding them. Classes do exist as objects in Java. See the "Class" class. I can say myObject.

You get only a "description" of the class -- not the class itself. But the difference is subtle. You still have class but it is hidden in the VM near the class loader , user have almost no access to it. To use clazz2 instanceof clazz1 properly you can instead use class2.

Jayanga Kaushalya 2, 5 5 gold badges 35 35 silver badges 56 56 bronze badges. I don't think, one should argue "static" vs "dynamic" by its internal implementation.

That's an language's API keyword. What is the programmer expecting? Yoon5oo 5 5 silver badges 11 11 bronze badges. Shubhamhackz Shubhamhackz 5, 4 4 gold badges 37 37 silver badges 62 62 bronze badges. It's bad practice to call static methods from object. Kevin Brock Kevin Brock 8, 1 1 gold badge 31 31 silver badges 37 37 bronze badges. Of course, there's no reason why Java couldn't pass a "Class" object as a hidden parameter to static methods. It just wasn't designed to do it. Athens Holloway Athens Holloway 2, 3 3 gold badges 17 17 silver badges 25 25 bronze badges.

Did you not read any of the other answer already covering this and making it clear that these are not reasons enough to discount overriding statics at the conceptual level. We know it doesnt work. It is perfectly "clean to desire the overriding of static methods and indeed it IS possible in many other languages. Richard, let's assume for a minute that when I responded to this question 4 years ago most of these answers had not been posted, so don't be an ass!

There is no need to assert that I did not read carefully. Furthermore, did you not read that we are only discussing overriding with respect to Java. Who cares what's possible in other languages. It's irrelevant. Go troll somewhere else.

Your comment does not add anything of value to this thread. Rupesh Yadav Rupesh Yadav Lars Lars 1, 6 6 silver badges 6 6 bronze badges. Intuitively, I would think it should work just like a virtual function. Why can't it do the same with static functions? After all, the compiler knows what class each object is an instance of. Jay, a static method need not be generally is not called on an instance If a static method is called using a classname, you'd use the method appropriate for the class.

But then what is overriding doing for you. If you call A. And if you have C or B then you are calling those versions anyway I am suggesting that an alternative design might have been a better idea. BTW, in a very real sense static functions are called with an instance quite routinely: When you call the static function from within a virtual function. Then you implicitly get this. DeveloperArnab DeveloperArnab 3 3 silver badges 11 11 bronze badges. I think Delphi was the first language implementing OOP used in commercial application development and wide-known.

Looks like I need to rephrase this statement — Patlatus. This is not true in a lot of instances where at runtime the static method is in fact called from an instance of the containing class and thus it's perfectly feasible to determine which instances of the function to invoke.

Sam Harwell A proper modern IDE will generate a warning when you do that though, so at least you can catch it while Oracle can keep the backwards compatibility thing going. You can overload a static method but you can't override a static method. Actually you can rewrite a static method in subclasses but this is not called a override because override should be related to polymorphism and dynamic binding. The static method belongs to the class so has nothing to do with those concepts.

The rewrite of static method is more like a shadowing. I design a code of static method overriding. I think It is override easily. Please clear me how its unable to override static members. Here is my code-. Refer static keyword. As any static method is part of class not instance so it is not possible to override static method. From Why doesn't Java allow overriding of static methods? Overriding depends on having an instance of a class. The point of polymorphism is that you can subclass a class and the objects implementing those subclasses will have different behaviors for the same methods defined in the superclass and overridden in the subclasses.

A static method is not associated with any instance of a class so the concept is not applicable. There were two considerations driving Java's design that impacted this.

One was a concern with performance: there had been a lot of criticism of Smalltalk about it being too slow garbage collection and polymorphic calls being part of that and Java's creators were determined to avoid that. Definitely, we cannot override static methods in Java. Because JVM resolves correct overridden method based upon the object at run-time by using dynamic binding in Java. However, the static method in Java is associated with Class rather than the object and resolved and bonded during compile time.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Can I override and overload static methods in Java? Ask Question. Asked 11 years, 8 months ago. Active 1 year, 6 months ago. Viewed k times. I'd like to know: Why can't static methods be overridden in Java?

Can static methods be overloaded in Java? Dup: stackoverflow. Add a comment. Active Oldest Votes. Static methods can not be overridden in the exact sense of the word, but they can hide parent static methods In practice it means that the compiler will decide which method to execute at the compile time, and not at the runtime, as it does with overridden instance methods. Overriding: Overriding in Java simply means that the particular method would be called based on the run time type of the object and not on the compile time type of it which is the case with overriden static methods Hiding: Parent class methods that are static are not part of a child class although they are accessible , so there is no question of overriding it.