Geek Answers Handbook

Security type: uncheck the class objects

I really like generics, etc., but in this special case I have a question regarding a warning like "Type: Unchecked cast from .. to ..".

Basically, I have objects of class Class, and now I want to get a subset of them that implement a special interface, but the resulting List should also have a special type:

...
private List<Class<?>> classes;

public List<Class<? extends Concrete>> getConcreteClasses() {

    List<Class<? extends Concrete>> concreteClasses = new LinkedList<Class<? extends Concrete>>();

    for (Class<?> clazz: this.classes) {
        for (Class<?> i : clazz.getInterfaces()) {
            if (i.equals(Concrete.class)) {
                concreteClasses.add((Class<? extends Concrete>) clazz);
            }
        }
    }

    return concreteClasses;

}

The warning, of course, is related to the cast type:

Type safety: Unchecked cast from Class<?> to Class<? extends Concrete>

Can I get rid of the cast type or should I suppress the warning with @SuppressWarnings ("unchecked")?

Thanks for answers!

PS: environment is Java 6.

Solution: Instead

concreteClasses.add((Class<? extends Concrete>) clazz);

using

concreteClasses.add(clazz.asSubclass(Concrete.class));
+5
source share
2

, , , , , Concrete...

0

More articles:


All Articles