Java Generics AnyType, how do I allow any method to be called?

Question

Given:

public<?> void methodName(? input){
  var something = ?.GetItNow();
}

We have a ton of classes that were auto-generated from WSDL. Almost all of them have the same methods, but there is no way to have them implement an interface for those same methods. Assume all these different classes have a method named GetItNow(). My question is how do I set up a Generic method to allow the code above to work?

When using the "?" do I have to always use the "extends" key-word? If so how do I extend any object so I don't see compile errors that "method doesn't exist.

Note the code above is for illustration purposes only and does not do anything (yet).

write a helper method/class/whatever which uses reflection to get the GetItNow value. — Vasilii Ruzov, Mar 21 '19 at 15:03
https://stackoverflow.com/questions/160970/how-do-i-invoke-a-java-method-when-given-the-method-name-as-a-string — Tyler Nichols, Mar 21 '19 at 15:04
if there is no way to group them (the methods) by an interface, there is no way to write a generic method for them — Andrew Tobilko, Mar 21 '19 at 15:21
Presumably you could auto-generate overloads of this method too. — Tom Hawtin - tackline, Mar 21 '19 at 15:29
Is there any known way to create a template for WSDL generation that we can inject the interface at class creation time? — JWP, Mar 21 '19 at 15:40
Check this: https://stackoverflow.com/questions/7652338/how-to-have-java-classes-generated-from-wsdl-implement-an-interface?rq=1 — Vasilii Ruzov, Mar 21 '19 at 15:46

score 2 · Accepted Answer · answered Mar 21 '19 at 15:06

You could use reflection to access the method, provided the name is known beforehand.

public void methodName(Object input){
    try{
        Method method = input.getClass().getMethod("GetItNow");
        RETURN_TYPE returnValue = (RETURN_TYPE)method.invoke(input);
    }catch(Exception e){
        throw new RuntimeException("Error while invoking method",e);
    }
}

Java Generics AnyType, how do I allow any method to be called?

1 Answers1