Dynamically Loading a Class with Parameters

Question

Hi,
I'm working on small program during my spare time and I have run into a problem. I have one abstract class (Foo) which is extended by several other subclasses (subFoo1, subFoo2). I am trying to avoid making a whole host of if statements depending on user input by coding in dynamic class loading.
The newInstance() method I've read about works well except that it does not accept arguments, something that I sorely need:
Foo a = Class.forName(input).asSubclass(Foo.class).newInstance();The other method works for creating the objects but I get an error:
Class foo = Class.forName(input);
Constructor cons = cs.getConstructor(new Class[]{String.class, Long.TYPE});
Object a = cons.newInstance(new Object[]{ FooString, FooInt});
a.method()
cannot find symbol
symbol : method(java.math.BigDecimal)
location : java.lang.ObjectI can understand the problem that the new 'Object' can't find the methods of 'foo', but i don't know how to solve the problem.

Answer 1

Object a = cons.newInstance(new Object[]{ FooString, FooInt});
a.method();That isn't very strange, is it? a is an Object, and class Object doesn't have the method you're calling. You have to cast it to a Foo:
Foo a = (Foo)cons.newInstance(new Object[]{ FooString, FooInt});
a.method();