Get type of a generic parameter in Java with reflection

java generics reflection
cimnine picture cimnine · Dec 14, 2009 · Viewed 184.1k times · Source

Is it possible to get the type of a generic parameter?

An example:

public final class Voodoo {
    public static void chill(List<?> aListWithTypeSpiderMan) {
        // Here I'd like to get the Class-Object 'SpiderMan'
        Class typeOfTheList = ???;
    }

    public static void main(String... args) {
        chill(new ArrayList<SpiderMan>());
    }
}

Answer

DerMike picture DerMike · Dec 14, 2009

One construct, I once stumbled upon looked like

Class<T> persistentClass = (Class<T>)
   ((ParameterizedType)getClass().getGenericSuperclass())
      .getActualTypeArguments()[0];

So there seems to be some reflection-magic around that I unfortunetly don't fully understand... Sorry.

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