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POHow to declare a Class<?> object such that is is an Enum AND an Interface in Java
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copied!<p>I have a utility class that needs to work on a generic Class but must be restricted to those that are an enum and implement a particular interface.</p> <pre><code>// These two work Class<? extends Enum<?>> enumClass; Class<? extends MyInterface> interfaceClass; // This is what I want but does not work Class<? extends MyInterface & Enum<?>> enumAndInterfaceClass; </code></pre> <p>For generics I can successfully use this</p> <pre><code>public class MyClass<T extends Enum<T> & MyInterface> { public MyClass(Class<T> theClass) { ... } } </code></pre> <p>However I can't use the Generics everywhere and need to declare it separately. I am not sure if this is even possible. <br/> So my question boils down to how can I declare a member variable with those constraints? </p> <p>So Currently MyClass is a singleton then as needed the enum/interface can be updated. The return values of its operations will change depending on which enum it is given. I would like to not have the generics on it since that would require creating a new instance for every change to the enum. There is a lot of code using it already so deviating from the singleton is not going to be approved. So a reference must be kept. I suppose I could only enforce the Interface requirement then check in the setter method that it is an enum throwing an exception otherwise but that is not ideal. </p> <p><strong>Edit</strong> (Updated question and added more detail)</p>

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