Invoking methods by name

Question

Is it possible (and if so how) to invoke a method using a name stored in a variable?
private void thisMethod(){
is normally run by using the method name:
thisMethod();
or
this.thisMethod();
But if there are a number of methods (method1, method2, method3 say) and the choice of which method to use is derived from some source (in my case as a jsp request parameter), is there some way of saying "run the method whose name is stored in variable methodName"?
The alternative is of course to use a lot of if ... else if statements, but there are situations where even that does not help very much.
Clearly what I am asking for is some kind of late binding, which should not be too hard for any language which can implement run time polymorphism, but how?
Good ideas and information welcome.
David

Answer 1

If you know the class then you can use reflection to do the job. You can get the methods names using instance.getClass().getDeclaredMethods(...);
If the methods have the same interface but differ in implementation then you could create an interface, have a number of classes implement the interface, then scan the classpath for classes that implement the interface.
there's probably more
Dave