New to Java

I want to take String Object, which represents the name of a class, then make an Object. If the String is "Mouse" then it will create a new Mouse Object.

This is the Mouse constructor:

public Mouse(int weight){ 
	this.weight = weight;
}

This is what I got so far for my code:

Class<?> c = Class.forName(sub);
Constructor<?> ctorlist[] = c.getDeclaredConstructors();

I don't know how to proceed from here. I checked some websites but they don't make a lot of sense to me. Can someone tell me how to create the object or at least provide a good website with a clear and easy to follow tutorial?

Thanks.

PS. I have to use reflections.