How to get generic container class of a ParameterizedType in java

Every questions about the java reflection on generic types I found, were asking about getting parameters of a generic type. In my case, I have a ParameterizedType and want to get the Generic container class.

For example, suppose a

ParameterizedTypeImpl.toString()

returns

java.util.List<test.Bar>

Now I want to get a Class of java.util.List.

It might sound a little wired for you, but I need you to suppose it is what it is!

So what I need is something like

 Class cls = ((MagicCast)ParameterizedTypeImpl.mayBeAMagicHere()).someOtherMagic();
 //Now cls is of type List

The only way I can think of is to use subString or regex to get java.util.List out of the ParameterizedTypeImpl.toString() and then use class.forName to get the class. But I don't know how portable it is. Is it possible some versions of java have other implementation for the toString of a ParameterizedTypeImpl?

Is there any better solution than that?

Thank you.