robinmag robinmag - 9 months ago 40
Java Question

How to get a class instance of generics type T

I have a generics class,

. In a method of
, I want to get the class instance of type T, but I just can't call

What is the preferred way to get around it using


The short answer is, that there is no way to find out the runtime type of generic type parameters in Java. I suggest reading the chapter about type erasure in the Java Tutorial for more details.

A popular solution to this is to pass the Class of the type parameter into the constructor of the generic type, e.g.

class Foo<T> {
    final Class<T> typeParameterClass;

    public Foo(Class<T> typeParameterClass) {
        this.typeParameterClass = typeParameterClass;

    public void bar() {
        // you can access the typeParameterClass here and do whatever you like