CODEWITHSUNDEEP
javaobjectoopmemorystatic
navyad
navyad

Reputation: 3860

Where static objects are stored in Java?

I'm reading a book "Thinking in Java" which says

objects are stored on heap and static variable are stored on some fixed location, saying it as static storage, so that they can be available for the entire time program when it is running.

class Myclass {    
  static int x =0; //stored on static storage
  Myclass obj = new Myclass(); //stored on heap    
}

Although making a object, static will not be a good idea as far as OOP is concerned. Putting this aside for a while, there comes my questions:

  1. Where does object, which is declared static, is stored.
  2. How does JVM instantiation of the object in this case.
class Myclass { 
  static Myclass obj = new Myclass(); //no man's land
}

Upvotes: 4

Views: 2767

Answers (4)

Den R
Den R

Reputation: 547

It depends on JVM implementation. In your example the variable is initialized to a primitive value and so it will be stored in metaspace(native memory, offheap). In case you initialized it with new ObjectClassSmthng() the object will be stored on heap and x variable (which is a reference) would be stored in metaspace.

This is true for HotSpot JDK 8.

Upvotes: 0

Ravindra Bagale
Ravindra Bagale

Reputation: 17655

static variables are stored on method area.
method area is part of non-heap memory. It stores per-class structures, code for methods and constructors. Per-class structure means runtime constants and static fields.
heap memory, non-heap memory and method area are the main jargon when it comes to memory and JVM.

Upvotes: 0

Roman C
Roman C

Reputation: 1

Static is a special memory location to the program. So the program could easily access it. Only one such location available for the program to run. And it's the place where static content is created. The JVM instantiates objects on the heap. But if you make a static reference to the object then it placed in the static memory place.

Upvotes: 1

kosa
kosa

Reputation: 66637

All static content will be created on class load/initiation and stored in special location (most probably part of perm gen, differs based on implementation).

For second example, When your Myclass is loaded, it's static content will be created/instantiated.

This tutorial may give you high level overview.

Upvotes: 3

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