Description Jeff Xiong 2005-06-30 04:53:00 EDT

If a method is generic and has varargs, such as:

//////// Fragment 1 //////////
public class Functor<T> {
	public void func(T... args) {

When invoking this method, such as:
		//////// Fragment 2 //////////
		Functor<String> functor = new Functor<String>();
		functor.func("Hello!");

The invoker should be compiled as following (with JDK 1.5.0):

	//////// Fragment 3 //////////
        functor.func(new String[] {
            "Hello!"
        });

but Eclipse 3.1 JDT compiled it as following:

	//////// Fragment 4 //////////
        functor.func(new Object[] {
            "Hello!"
        });

If there's an inner class which overriden this method, such as:

		//////// Fragment 5 //////////
		Functor<String> functor = new Functor<String>() {
			public void func(String... args) {
				System.out.println(args.length);
			}
		};

it will be compiled with two methods, one is a volatile delegation, another is 
really functional, as following:

//////// Fragment 6 //////////
static class Functor$1 extends Functor
{

    public transient void func(String as[])
    {
        System.out.println(as.length);
    }

    public volatile void func(Object aobj[])
    {
        func((String[])aobj);    // ClassCastException here
    }

Combine Fragment 4 and Fragment 6, there will be a ClassCastException thrown. 
Fragment 3 should be correct.