Get generic type of java.util.List

Question

I have;

List<String> stringList = new ArrayList<String>();
List<Integer> integerList = new ArrayList<Integer>();

Is there a (easy) way to retrieve the generic type of the list?

Answer 1

You can do the same for method parameters as well:

Type[] types = method.getGenericParameterTypes();
//Now assuming that the first parameter to the method is of type List<Integer>
ParameterizedType pType = (ParameterizedType) types[0];
Class<?> clazz = (Class<?>) pType.getActualTypeArguments()[0];
System.out.println(clazz); //prints out java.lang.Integer

Answer 2

The type is erased so you will not be able to. See http://en.wikipedia.org/wiki/Type_erasure and http://en.wikipedia.org/wiki/Generics_in_Java#Type_erasure