Question

How do I know which class called a method?

class A {
   B b = new B();

   public void methodA() {
    Class callerClass = b.getCallerCalss(); // it should be 'A' class
   } 
}

class B {
 public Class getCallerCalss() {
   //... ???
   return clazz;
 }
}

Answer 1

This is easily done with Thread.currentThread().getStackTrace().

public static void main(String[] args) {
    doSomething();
}

private static void doSomething() {
    System.out.println(getCallerClass());
}

private static Class<?> getCallerClass() {
    final StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
    String clazzName = stackTrace[3].getClassName();
    try {
        return Class.forName(clazzName);
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
        return null;
    }
}

[3] is used because [0] is the element for Thread.currentThread(), [1] is for getCallerClass, [2] is for doSomething, and finally, [3] is main. If you put doSomething in another class, you’ll see it returns the correct class.