9.5.2 Class-wise statistical information output by the STATIC member statistical functionality

(1) Output format and output items

The output format of the class-wise statistical information output by the STATIC member statistical functionality is as follows:

• Output format

  Java Heap Dump Static Profile
  -----------------------
  ________________Size__Instances__Class________________
   <total_size> <Instance_count> <class_name>
   <total_size> <Instance_count> <class_name>
  ...

• Output items

  The items listed in the output format are described as follows.

  Table 9‒8: Output items (STATIC member statistical functionality)

  Output items	Meaning
  <total_size>	The total size of the instance is output in byte unit.
  <Instance_count>	The number of instance is output.
  <class_name>	The class name is output.

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(2) Output examples

The output example of the class-wise statistical information output by the STATIC member statistical functionality, is described as an example of the following source:

public class static_instance {
  public static void main(String args[]) {
    classA cls_a;
    classB cls_b;
    classC cls_c;
 
    cls_a = new classA();
    cls_b = new classB();
    cls_c = new classC();
    cls_b.cls_c = cls_c;
    cls_a.cls_b = cls_b;
 
    try {
      Thread.sleep(20000);
    } catch (Exception e) {}
 }
}
class classA {
 static classB cls_b;
}
class classB {
 classC cls_c;
}
class classC {
}

The following figure shows the output result of the STATIC member statistical functionality.

Figure 9‒4: Output result (STATIC member statistical functionality)

Moreover, there is a difference in the reference relation for the above source in the instance statistical functionality and in the STATIC member statistical functionality and the following figure shows this difference.

Figure 9‒5: Difference in reference relation in the instance statistical functionality and in the STATIC member statistical functionality

The reference relation of the respective functionality is as follows:

• Reference relation of the instance statistical functionality

  Instance variable cls_b of Instance A ->Instance variable cls_c of instance B -> Instance C

• Reference relation of the STATIC member statistical functionality

  Class variable cls_b of class A ->Instance variable cls_c of instance B -> Instance C

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