Get generic type of class at runtime
As others mentioned, it's only possible via reflection in certain circumstances.
If you really need the type, this is the usual (type-safe) workaround pattern:
public class GenericClass<T> { private final Class<T> type; public GenericClass(Class<T> type) { this.type = type; } public Class<T> getMyType() { return this.type; }}
I have seen something like this
private Class<T> persistentClass;public Constructor() { this.persistentClass = (Class<T>) ((ParameterizedType) getClass() .getGenericSuperclass()).getActualTypeArguments()[0]; }in the hibernate GenericDataAccessObjects Example
Generics are not reified at run-time. This means the information is not present at run-time.
Adding generics to Java while mantaining backward compatibility was a tour-de-force (you can see the seminal paper about it: Making the future safe for the past: adding genericity to the Java programming language).
There is a rich literature on the subject, and some people are dissatisfied with the current state, some says that actually it's a lure and there is no real need for it. You can read both links, I found them quite interesting.