Product Version = NetBeans IDE 8.1 (Build 201510222201)
Operating System = Windows 10 version 10.0 running on amd64
Java; VM; Vendor = 1.8.0_72
Runtime = Java HotSpot(TM) 64-Bit Server VM 25.72-b15

Reproducibility: Happens every time

STEPS:
  * Open dialog Foo
  * Click on button "Click me"

ACTUAL:
  nothing happens

EXPECTED:
  message pops up


For a String Object in a class, which by reflection is accessible from the Field, return null when casted to int[][][][][], the rouitne used is from Class class

    /**
     * Casts an object to the class or interface represented
     * by this {@code Class} object.
     *
     * @param obj the object to be cast
     * @return the object after casting, or null if obj is null
     *
     * @throws ClassCastException if the object is not
     * null and is not assignable to the type T.
     *
     * @since 1.5
     */
    @SuppressWarnings("unchecked")
    public T cast(Object obj) {
        if (obj != null && !isInstance(obj))
            throw new ClassCastException(cannotCastMsg(obj));
        return (T) obj;
    }


thus:

public Class MyClass {

public String name;

public void function() {
	Field[] ff = getClass().getFields();
	if (ff != null) {
                        for (Field field : ff) {
                            try {
                                int[][][][][] fv = int[][][][][].class.cast(field.get(this));
                             } catch (ClassCastException e) {

                            }
                        }
	
	}
}

return in function for fv null when function is called, wheras the javadoc states a cast exception is thrown