Get the outer class object from an inner class object

Question

In a nutshell, I'm trying to do the inverse of "classObject.getDeclaredClasses()".

I have a method that receives an object of type Class<? extends Object>. I want to figure out whether it is an inner class, and if it is, I want to access the surrounding class' object instance.

Is there a smart API for this, or am I forced to do some string manipulation and parsing?

Answer 1

You are looking for the Class.getDeclaringClass() method:

public Class getDeclaringClass()

If the class or interface represented by this Class object is a member of another class, returns the Class object representing the class in which it was declared. This method returns null if this class or interface is not a member of any other class. If this Class object represents an array class, a primitive type, or void,then this method returns null.

Returns: the declaring class for this class

Answer 2

Referencing the Outer Class Instance From the Inner Class Code

If inner class code needs a reference to the outer class instance that it is attached to, use the name of the outer class, a dot, and this

* remember that if there is no name conflict, there is no need for any special syntax
* for code in MyInner to obtain a reference to its MyOuter:

  MyOuter.this

static Inner Classes

An inner class may be marked as static

A static inner class my be instantiated without an instance of the outer class

* static members of the outer class are visible to the inner class, no matter what their access level
* non-static members of the outer class are not available, since there is not instance of the outer class to retrieve them from