Class extends another class and implements interface in java can be casted to anyd of these types?

Question

I have spring bean like:

 <bean id="testBean" class="TestBean"
  ......
  <property name="resolver" ref="resolver"....

class Resolver extends BaseResolver implements IManagementInterface

in class TestBean setter:

 public void setResolver (IManagementInterface resolver) {
 this.resolver=resolver;
 ...

But when I run I receive exception:

Cannot convert value of type Resolver to required type IManagementInterface.

But this seems not correct - because Resolver is also type IManagementInterface. What the sense of this error? Or may be I should clean install all my project?

Can you post `` complete definition? – Grzegorz Rożniecki Apr 23 '12 at 09:44 — Grzegorz Rożniecki, Apr 23 '12 at 09:44

score 2 · Accepted Answer · edited May 23 '17 at 12:31

Do a clean install first. If this doesn't make the problem disappear, you might be experiencing a classloader problem. If your Resolver instance (and the corresponding class declarations) was loaded by a different classloader than TestBean, it belongs to a different classloader realm, and it (or specifically its super interface IManagementInterface) is thus seen by the JVM as a completely different type from the IManagementInterface parameter type of TestBean.setResolver. So one can't be cast to another.

See this earlier answer of mine for a way to verify whether or not this is the root cause.

Class extends another class and implements interface in java can be casted to anyd of these types?

1 Answers1