Get heap memory used by method in java class

Question

I am writing Java code and I want to run some performance tests. I want to get the heap memory used by only one of the methods in my class.

 public AccessControl {

     public boolean Allowed () {
        code
        }
     public  void print () {
    code }
}

I want to get the heap memory used in java every time the Allowed method is called at runtime. I read that I can do this with HPROf, but I noticed that HPROf does not provide memory computation for methods, but only for classes, is there code that I can write inside the method to get the available memory and then the used memory? thank

Answer 1

There is no such thing as “heap memory used by a method”. Ways do not take up heap memory, objects do.

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Answer 2

InMemProfiler . .

# tracetarget-org.yourcode.YourClass, " ", YourClass.

. . , git fork InMemProfiler .

Answer 3

, , . HPROF , , . JProfiler. , , , . .

Answer 4

oracle jvm, !

ThreadMXBean threadmx = ManagementFactory.getThreadMXBean();
long startbyte = ((com.sun.management.ThreadMXBean)threadmx)
    .getThreadAllocatedBytes(Thread.currentThread().getId());
//call method
int usedbyte = ((com.sun.management.ThreadMXBean)threadmx)
    .getThreadAllocatedBytes(Thread.currentThread().getId())-startbyte;

Answer 5

One way is to use a memory profiler such as jprofiler , but if you just want to see the memory used by the application set, the code below is used

Runtime runtime = Runtime.getRuntime();
long memoryUsedBefore = runtime.totalMemory() - runtime.freeMemory();
System.out.println("Memory used before: " + memoryUsedBefore );
    // set of memory consumption statements here
long memoryUsedAfter = runtime.totalMemory() - runtime.freeMemory();
System.out.println("Total Memory increased:" + (memoryUsedAfter - memoryUsedBefore ));