What does getstatic really mean in bytecode?

Question

I have this byte code:

new                 java.lang.Object
// stack is [newObjectRef]
dup 
// Stack is [newObjectRef newObjectRef]
invokespecial       void java.lang.Object.<init>()
// Stack is [initializedAsTypeObjectObjectRef]
putstatic           java.lang.Object class.a
// variable a has the reference of new object
getstatic           java.io.PrintStream java.lang.System.out
// Take the static value of System.out
// Stack is [initializedAsTypeObjectObjectRef System.out]

Update this is the continuation:

> ldc                 "test" // Stack is
> [initializedAsTypeObjectObjectRef System.out "test"]
> jsr                  pos.0000026C // call a subrutine invokevirtual       void
> java.io.PrintStream.println(java.lang.String) // actually print the
> result // stack is (I think) Empty at this time ?

Does the translation is:

  Object a = new Object();
  a = "test";
  System.out.print(a);

Is my stack good ?

I am not sure to well understand out(). Probably I will have to use out() setter and to print() after ?

I always use out() to print habitually..

Answer 1

If I compile the code

public static void main(String[] args) {
    Object a;
    a = "test";
    System.out.println(a);
}

and run

javap -c Main

I see

public static void main(java.lang.String[]);
Code:
   0: ldc           #2                  // String test
   2: astore_1      
   3: getstatic     #3                  // Field java/lang/System.out:Ljava/io/PrintStream;
   6: aload_1       
   7: invokevirtual #4                  // Method java/io/PrintStream.println:(Ljava/lang/Object;)V
  10: return    

You can see that getstatic loads the field System.out

---

Object doesn't have a method called out() so I don't believe you are looking at the code you believe you are.

getstatic gets a static fields e.g. System.out is a static field of System so if you write

System.out.println();

This will result in a use of getstatic