How can i know the name of class who is calling my class ? i need not want the callee to provide any information abut its class

Question

I need an suggestion on this

 class A{
    B b;
 }

 Class B{
    P String  something();
 }

In

 class test{
    B b = new B();
    b.something();
 }

something()

must return the name of the cal-lee class its like if somebody calls me(by name) I should know his name.

please check below link. http://stackoverflow.com/questions/421280/in-java-how-do-i-find-the-caller-of-a-method-using-stacktrace-or-reflection Hope it helps to you — Mallikarjuna Reddy, Mar 07 '13 at 08:25
If you need to know who is calling you, you most likely have a design/architectural issue. — dty, Mar 07 '13 at 08:55

score 6 · Answer 1 · edited Mar 07 '13 at 08:31

6

A solution is to programmatically generate a stack trace:

private static String getCallerName() {
    StackTraceElement[] stElements = Thread.currentThread().getStackTrace();
    for (int i=1; i<stElements.length; i++) {
        StackTraceElement ste = stElements[i];
        if (!ste.getClassName().equals("B") && ste.getClassName().indexOf("java.lang.Thread")!=0) {
            return ste.getClassName();
            // you could also use ste.getMethodName() or ste.getLineNumber()
        }
    }
    return null;
}

You would use it like this, for example :

public void something() {
   System.out.println("called by " + getCallerName());
}

edited Mar 07 '13 at 08:31

Edward Samson

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answered Mar 07 '13 at 08:24

Denys Séguret

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May i know where all have you used this? (stand alone, distributed) – aksappy Mar 07 '13 at 08:27
+1, I did a if(true){try{throw new NullpointerException()}catch(Exception ex){ and here I had the stack trace }} :) – Mar 07 '13 at 08:27
@aksappy I'm not sure I get your comment. I use a similar thing in some debug tools. – Denys Séguret Mar 07 '13 at 08:28
Is there any alternate method to do instead of StackTraceElement[] ? – user2143318 Mar 11 '13 at 06:22
@user2143318 Why ? This makes only sense when logging or debugging. What's the problem you have with the stack trace ? – Denys Séguret Mar 11 '13 at 06:44

score 0 · Answer 2 · answered Mar 07 '13 at 08:23

0

If somebody calls you by name, you wouldn't know it, unless that somebody already told it to you.

Same thing here.

Pass your name from class A to class B.

answered Mar 07 '13 at 08:23

Allan Spreys

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ya ,i should not know it.But my requirement is to know the person calling me.Thanks for giving a different look to the problem. – user2143318 Mar 11 '13 at 06:20

score 0 · Answer 3 · answered Mar 07 '13 at 08:32

0

As the problem seems a bit extraordinary, an architectural alternative. Whether it fits better I do not know.

class A {
    class C extends B {
        String something() {
            ... A.this
        }
    }
}

answered Mar 07 '13 at 08:32

Joop Eggen

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How can i know the name of class who is calling my class ? i need not want the callee to provide any information abut its class

3 Answers3