Reflection - The Java Programming Language - page 622

zero-length Annotation array is provided for that parameter. If the Method
object represents a method that is itself an element of an annotation,
the geTDefaultValue method returns an Object representing the default
value of that element. If it is not an annotation element or if there is no
default value, then null is returned.
The Method class also implements GenericDeclaration and so defines the
method getTypeParameters which returns an array of TypeVariable objects.
If a given Method object does not present a generic method, then an
empty array is returned.
You can ask a Method object if it is a varargs (variable-argument) method
using the isVarArgs method. The method isBridge asks if it is a bridge
method (see Section A.3.1 on page 745 ) .
The most interesting use of a Method object is to reflectively invoke it:
public Object invoke(Object onThis, Object... args) tHRows Illeg-
alAccessException, IllegalArgumentException, InvocationTargetExcep-
tion
Invokes the method defined by this Method object on the ob-
ject onThis , setting the parameters of the method from the
values in args . For non-static methods the actual type of
onThis determines the method implementation that is invoked.
For static methods onThis is ignored and is traditionally null .
The number of args values must equal the number of para-
meters for the method, and the types of those values must
all be assignable to those of the method. Otherwise you will
get an IllegalArgumentException . Note that for a varargs meth-
od the last parameter is an array that you must fill with the
actual "variable" arguments you want to pass. If you attempt
to invoke a method to which you do not have access, an Il-
legalAccessException is thrown. If this method is not a method
of the onThis object, an IllegalArgumentException is thrown. If
onThis is null and the method is not static, a NullPointerExcep-
tion is thrown. If this Method object represents a static method