Trespassers will be prostituted: Bean instances from Spring context must be cast into interface, not implementing class

Bean instances from Spring context must be cast into interface, not implementing class

Mei 27, 2013 By Firman

So I have interface Thinker, and a class Volunteer implementing that interface.

I have a bean like this in my context.xml:

And in the Java code:

Thinker vol = (Volunteer)context.getBean("thinker");

I got the following exception:

Exception in thread "main" java.lang.ClassCastException: com.sun.proxy.$Proxy1 cannot be cast to springidol.classes.Volunteer

It turns out that I must cast all beans instantiated from context into its interface, not its implementing class. The following Java code is correct:

Thinker vol = (Thinker)context.getBean("thinker");

Label: Spring |