Troubleshooting
Problem
You receive a ClassCastException when casting a remote Enterprise Java™Beans home or remote interface stub instance to its actual remote home interface or remote interface type. When resolving a remote EJB home reference or a local EJB home reference, an application programmer may "cleverly" attempt to narrow the result of a JNDI lookup using the EJBHome class rather than the exact home class (type) in order to generalize the task. Here is an example involving a remote Enterprise JavaBeans, MyBean and it's corresponding home, MyHome:
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InitialContext context = new InitialContext();
Object remoteObj = context.lookup("java:comp/env/ejb/MyHomeName");
EJBHome ejbHome = PortableRemoteObject.narrow(remoteObj, EJBHome.class):
MyBean myBean = (MyBean)ejbHome.create();
...
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Symptom
In this example, a ClassCastException indicating class MyBean_Stubxxx occurs when the application casts the result of myHome.create() to class MyBean. The explanation is provided below.
A ClassCastException occurs if myHome (an instance of EJBHome, above) is cast to its actual type, MyHome. The following example statements also result in a ClassCastException indicating the MyHome_Stubxxx class:
MyHome myHome = (MyHome)ejbHome;
Which is synonymous with:
MyHome myHome = (MyHome)PortableRemoteObject.narrow(object, EJBHome.class):
Because the code snippets above violate the Enterprise JavaBeans 2.0 specification with regard to narrowing remote EJB references, their expected behavior is indeterminate.
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Document Information
More support for:
WebSphere Application Server
Software version:
9.0, 8.5.5, 8.0, 7.0
Operating system(s):
AIX, HP-UX, Linux, Solaris, Windows
Document number:
81059
Modified date:
03 March 2025
UID
swg21192568