CODEWITHSUNDEEP
javareflectionstatic
Greg Witczak
Greg Witczak

Reputation: 1684

get caller class name from inherited static method

I have following classes (note that methods are static):

class Base
{
   public static void whosYourDaddy()
   {
      Class callerClass = // what should I write here to get caller class?
      System.out.print(callerClass.getName());
   }
}

Class A extends Base
{
   public static void foo()
   {
      A.whosYourDaddy();
   }
}

Class B extends Base
{
   public static void bar()
   {
      B.whosYourDaddy();
   }
}

And when I call:

A.foo();
B.bar();

I'd like to get output: AB instead of BaseBase. Is it even possible with static methods (in Java 7)?

Upvotes: 8

Views: 6892

Answers (3)

zhanhb
zhanhb

Reputation: 1

 private static class Reflection {
    private static final SecurityManager INSTANCE = new SecurityManager();
    static Class getCallClass() {
        return INSTANCE.getCallClass(2);
    }
    private Reflection() {
    }
    private static class SecurityManager extends java.lang.SecurityManager {
        public Class getCallClass(int i) {
            Class[] classContext = getClassContext();
            if (i >= 0 && i + 1 < classContext.length) {
                return classContext[i + 1];
            }
        return null;
        }
    };
}

Upvotes: 0

Ben Brammer
Ben Brammer

Reputation: 998

What you can do, but shouldn't :) is use the Throwable getStackTrace method. Aside from the smell, this is pretty slow, because getting the stack trace isn't that fast. But you will get an array of StackTraceElement, and each one will contain the class of teh class that is calling it (and you can also get the file and line, and if you separate the two with a : you can get a clickable link in eclipse, not that I'd ever do such a thing...).

Something like 

String className = new Throwable().getStackTrace()[1].getClassName();

Hope that helps :)

Upvotes: 8

Muel
Muel

Reputation: 4425

Is it even possible with static methods (in Java 7)?

No, Static methods aren't inherited. Only non-static methods are inherited.

In your case change Base (and subclasses) as follows:

class Base
{
  public void whosYourDaddy()
  {
    Class<?> callerClass = getClass();
    System.out.print(callerClass.getName());
  }
}

Upvotes: -1

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