Use instanceof in a generic way

Question

Is there a way to use instanceof based on the passed argument of a method? Example

doSomething(myClass.class); /* I would like to call this also with other classes */

public void doSomething(/*generic parameter that accepts all classes, not just myClass */) {
  if (myObject instanceOf /* the generic parameter */ == true) {...}
}

sometimes I'll call the method using myClass.class but other times I would like to call it using someOtherClass.class - I don't want to change the if condition though. Is that possible? If so, how? :)

Thanks

Yair Zaslavsky · Accepted Answer · 2012-12-07 22:05:13Z

7

You're looking for the Class.isInstance() method.

public void doSomething(Class<?> c, Object myObject) {
    if (c.isInstance(myObject)) {...}
}

edited Dec 7, 2012 at 22:05

Yair Zaslavsky

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answered Dec 7, 2012 at 17:30

SLaks

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1 Comment

Brian Over a year ago

Although, technically speaking, this is changing the if condition. Still, +1, exactly what I would have suggested.

Yair Zaslavsky · Accepted Answer · 2012-12-07 17:30:38Z

2

This is the way to do it, as far as I know:

public static <T> boolean doInstanceOf(Object object,Class<T> clz) {
        return clz.isInstance(object);
    }

Usage:

System.out.println(doInstanceOf(myObject,MyClass.class));

answered Dec 7, 2012 at 17:30

Yair Zaslavsky

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