Question

Somebody help me with these generics!

If you have an overloaded method with different types which can be an argument, can one write a generic method which at runtime call the right one? (Sorry if my java-nology is poor, if so)

Example:

public interface CoolInterface {
   setOverloadedValue(String o);
   setOverloadedValue(Integer o);
   setOverloadedValue(Date o);
}

public interface ClazzProvider {
   Class getClazz();
}

public class SomeUncoolClass {

   @AutowiredMagic CoolInterface coolGuy;
   @AutowiredMagic ClazzProvider clazzyProvider;

   public void helpMeMethod() {
      coolGuy.setOverloadedValue(getValue(clazzyProvider.getClazz()));
   }

   private ??? getValue(???) {
      return ???;
   }
}

What is the method signature of getValue()? And how can i implement it?

Answer 1

No – the overload is selected at compile time, and the compiler can’t tell which overload you want to use.

You might want to have a look at at the Visitor Pattern as a workaround for the case where the types you want to accept are under your control – it doesn’t help much when you want to accept String/Date/Object though 🙁