Get generic type of class at runtime

Question

How can I achieve this?

public class GenericClass
{
    public Type getMyType()
    {
        //How do I return the type of T?
    }
}

Answer 1

Java generics are mostly compile time, this means that the type information is lost at runtime.

class GenericCls
{
    T t;
}

will be compiled to something like

class GenericCls
{
   Object o;
}

To get the type information at runtime you have to add it as an argument of the ctor.

class GenericCls
{
     private Class type;
     public GenericCls(Class cls)
     {
        type= cls;
     }
     Class getType(){return type;}
}

Example:

GenericCls instance = new GenericCls(String.class);
assert instance.getType() == String.class;