This question already has answers here:
How do I test a class that has private methods, fields or inner classes?
(58 answers)
Closed 8 years ago.
I have some abstract class and some classes that inheritance from it.
I want to make JUNIT tester for it. I tried use reflect on the sub classes but in this way I cant see the private variables in the absract class.
how can I get to, Or maybe I can create instance of the abstract class for this?
To see all fields of a class use Class.getDeclaredFields()
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Are static variables inherited
(4 answers)
Closed 6 months ago.
Recently, I was trying to use interfaces to store some information which I needed to use globally. Initially, I was going to make every class which needed the information implement this interface to access the data. However, I eventually realized the enormously better solution of using the fact that variables are final and static to just get the data from a static call.
Through this journey I now have a question. When a class implements an interface with variables, does each class independently store the variables in new memory, or does it just get stored once in the interface. Kind of a weird question which I couldn't find an answer to.
Static fields are stored once within their class or interface, they are not duplicated in every instance
This question already has answers here:
Java doesn't support multiple inheritance but implicitly every class in java extends Object and allows one more [duplicate]
(8 answers)
Closed 2 years ago.
Every class is inherited from Object class and they will also extend some other parent class in inheritance why is it not considered as multiple inheritance.
It's because in Java you can directly inherit from only one parent class. We would consider multiple inheritance if you'd be able to extend from multiple classes but that's not a thing in Java.
This question already has answers here:
Why instantiation of static nested class object is allowed?
(3 answers)
Can a static nested class be instantiated in Java?
(5 answers)
What does the 'static' keyword do in a class?
(22 answers)
Static Classes In Java
(14 answers)
Closed 3 years ago.
I know that java doesn't support static Top-Level classes, and only nestled classes can be static.
But, wherever I read about these nestled static classes, it says you have to initialize these classes with the "new" keyword.
Is this not instancing? if yes, how are we instancing "static" classes?
Does this mean we can have multiple instances of this class running simultaneously? Can we store these on variables just like non-static classes?
If this is true, then is the "static" modifier just a modifier used to access the nestled class without instantiating the container class?
Any Light shed on these questions are very welcome. Thanks!
EDIT: This question is different than the questions it has been marked duplicate against as I am NOT asking what the static modifier does to an object, nor am I asking if static classes exist. I know what static nestled classes are, and how static objects behave, but the static nestled class'es peculiar behaviour of being instantiatable by using the"new" keyword (which is used to create an instance of an object). Static classes can usually not be created instances of in OOP, and I was asking is this different in java. can you create instances of static classes in java.
This question already has answers here:
What is the difference between public, protected, package-private and private in Java?
(30 answers)
Closed 7 years ago.
I am new to java. Can anyone please tell me best way to access private method variables in another class. Thank u
Private variables are private for a reason- you're not supposed to be able to access them directly. Many classes do have getter methods though which allow you to access private variables but not change them. If you need to access private variables in your program, you need to rethink your design.
This question already has answers here:
Why are you not able to declare a class as static in Java?
(14 answers)
Closed 9 years ago.
This question has been asked here earlier too. But i did not find it helpful.
It is just based on an assumption. please throw some insight on this.
static classes means there is no reference to an instance of an outer class.
Top level classes cannot have a reference to an outer class, so in a way they are all static classes.
The reason you can't make them static, is there is no other option and the syntax for top level classes was determined before there was a option for nested classes.
Your question doesn't mean anything. Whether an inner class is static or not basically means, is an instance of that inner class associated with a particular instance of the outer class. If a class is not an inner class, it doesn't mean anything to say that it's static or not static.