Cannot access an enterprise bean

 

1. javax.naming.NameNotFoundException... Name name not found in context "local" message when access is attempted

2. BeanNotReentrantException is thrown

3. CSITransactionRolledbackException / TransactionRolledbackException

4. Stack trace beginning EJSContainer E Bean method threw exception [exception_name]

5. ObjectNotFoundException or ObjectNotFoundLocalException when accessing stateful session EJB

6. Attempt to start CMP EJB module fails with javax.naming.NameNotFoundException: dataSourceName

7. Transaction [tran ID] has timed out after 120 seconds error accessing EJB.

8. Symptom: CNTR0001W... A Stateful SessionBean could not be passivated

9. Symptom: org.omg.CORBA.BAD_PARAM... Servant is not of the expected type. minor code: 4942F21E completed: No

If the client is remote to the enterprise bean, which means, running in a different appserver or as a stand-alone client, browse the JVM logs of the application server hosting the enterprise bean as well as log files of the client.

If you do not see a problem that resembles yours, or if the information provided does not solve your problem, perform these steps...

1. If the problem appears to be name-service related, which means that you see a NameNotFoundException, or a message ID beginning with NMSV, see these topics for more information...

   • Cannot look up an object hosted by WAS from a servlet, JSP file, or other client

   • Naming services component troubleshooting tips

2. Check to see if the problem is identified and documented using the links in Diagnosing and fixing problems... Resources for learning.

If you still cannot fix your problem, seeObtaining help from IBM for further assistance.

 

ObjectNotFoundException or ObjectNotFoundLocalException when accessing stateful session EJB

A possible cause of this problem is that the stateful session bean timed out and was removed by the container. This event must be addressed in the code, according to the EJB 2.0 specification (available at http://java.sun.com/products/ejb/docs.html ), section 7.6.2, Dealing with exceptions.

 

Stack trace beginning "EJSContainer E Bean method threw exception [exception_name]" found in JVM log file

If the exception name indicates an exception thrown by an IBM class that begins with "com.ibm...", then search for the exception name within the information center, and in the online help as described below. If "exception name" indicates an exception thrown by your application, contact the application developer to determine the cause.

 

javax.naming.NameNotFoundException: Name name not found in context "local"

A possible reason for this exception is that the enterprise bean is not local (not running in the same Java virtual machine [JVM] or appserver) to the client JSP, servlet, Java application, or other enterprise bean, yet the call is to a "local" interface method of the enterprise bean . If access worked in a development environment but not when deployed to WAS, for example, it might be that the enterprise bean and its client were in the same JVM in development, but are in separate processes after deployment.

To resolve this problem, contact the developer of the enterprise bean and determine whether the client call is to a method in the local interface for the enterprise bean. If so, have the client code changed to call a remote interface method, or to promote the local method into the remote interface.

References to enterprise beans with local interfaces are bound in a name space local to the server process with the URL scheme of local:. To obtain a dump of a server local: name space, use the name space dump utility described in the article "Name space dump utility for java:, local: and server name spaces."

 

BeanNotReentrantException is thrown

This problem can occur because client code (typically a servlet or JSP file) is attempting to call the same stateful SessionBean from two different client threads. This situation often results when an application stores the reference to the stateful session bean in a static variable, uses a global (static) JSP variable to refer to the stateful SessionBean reference, or stores the stateful SessionBean reference in the HTTP session object. The application then has the client browser issue a new request to the servlet or JSP file before the previous request has completed.

To resolve this problem, ask the developer of the client code to review the code for these conditions.

 

CSITransactionRolledbackException / TransactionRolledbackException is thrown

An enterprise bean container throws these high-level exceptions to indicate that an enterprise bean call could not successfully complete. When this exception is thrown, browse the JVM logs to determine the underlying cause.

Some possible causes include...

• The enterprise bean might throw an exception that was not declared as part of its method signature. The container is required to roll back the transaction in this case. Common causes of this situation are where the enterprise bean or code that it calls throws a NullPointerException, ArrayIndexOutOfBoundsException, or other Java runtime exception, or where a BMP bean encounters a JDBC error. The resolution is to investigate the enterprise bean code and resolve the underlying exception, or to add the exception to the problem method signature.

• A transaction might attempt to do additional work after being placed in a "Marked Rollback", "RollingBack", or "RolledBack" state. Transactions cannot continue to do work after they are set to one of these states. This situation occurs because the transaction has timed out which, often occurs because of a database deadlock. Work with the application database management tools or administrator to determine whether database transactions called by the enterprise bean are timing out.

• A transaction might fail on commit due to dangling work from local transactions. The local transaction encounters some "dangling work" during commit. When a local transactions encounters an "unresolved action" the default action is to "rollback". You can adjust this action to "commit" in the Assembly Toolkit. Open the enterprise bean .jar file (or the EAR file containing the enterprise bean) and select the Session Beans or Entity Beans object in the component tree on the left. The Unresolved Action property is on the IBM Extensions tab of the container properties.

 

Attempt to start EJB module fails with "javax.naming.NameNotFoundException dataSourceName_CMP"exception

This problem can occur because...

• When the DataSource resource was configured, container managed persistence was not selected.

  • To confirm this problem, in the administrative console, browse the properties of the data source given in the NameNotFoundException. On the Configuration panel, look for a check box labeled Container Managed Persistence.

  • To correct this problem, select the check box for Container Managed Persistence.

• If container managed persistence is selected, it is possible that the CMP DataSource could not be bound into the namespace.

  • Look for additional naming warnings or errors in the status bar, and in the hosting appserver JVM logs. Check any further naming-exception problems that you find by looking at the topic Cannot look up an object hosted by WAS from a servlet, JSP file, or other client.

 

Transaction [tran ID] has timed out after 120 seconds accessing an enterprise bean

This error can occur when a client executes a transaction on a CMP or BMP enterprise bean.

• The default timeout value for enterprise bean transactions is 120 seconds. After this time, the transaction times out and the connection closes.

• If the transaction legitimately takes longer than the specified timeout period, go to Manage Application Servers > server, select the Transaction Service properties page, and look at the property Total transaction lifetime timeout. Increase this value if necessary and save the configuration.

 

Symptom:CNTR0001W: A Stateful SessionBean could not be passivated

This error can occur when a Connection object used in the bean is not closed or nulled out.

To confirm this is the problem, look for an exception stack in the JVM log for the EJB container that hosts the enterprise bean, and looks similar to

[time EDT] <ThreadID> StatefulPassi W CNTR0001W: 
A Stateful SessionBean could not be passivated: StatefulBeanO
(BeanId(XXX#YYY.jar#ZZZZ, <ThreadID>), 
state = PASSIVATING) com.ibm.ejs.container.passivator.StatefulPassivator@<ThreadID>
java.io.NotSerializableException: com.ibm.ws.rsadapter.jdbc.WSJdbcConnection 
 at java.io.ObjectOutputStream.outputObject((Compiled Code)) 
 at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java(Compiled Code)) 
 at java.io.ObjectOutputStream.outputClassFields((Compiled Code)) 
 at java.io.ObjectOutputStream.defaultWriteObject((Compiled Code)) 
 at java.io.ObjectOutputStream.outputObject((Compiled Code)) 
 at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java(Compiled Code)) 
 at com.ibm.ejs.container.passivator.StatefulPassivator.passivate((Compiled Code)) 
 at com.ibm.ejs.container.StatefulBeanO.passivate((Compiled Code) 
 at com.ibm.ejs.container.activator.StatefulASActivationStrategy.atUnitOfWorkEnd
                      ((Compiled Code)) 
 at com.ibm.ejs.container.activator.Activator.unitOfWorkEnd((Compiled Code)) 
 at com.ibm.ejs.container.ContainerAS.afterCompletion((Compiled Code)

where XXX,YYY,ZZZ is the Bean's name, and <ThreadID> is the thread ID for that run.

To correct this problem, the application must close all connections and set the reference to null for all connections. Typically this activity is done in the ejbPassivate() method of the bean. See the enterprise bean specification mandating this requirement, specifically section 7.4 in the EJB specification Version 2.0. Also, note that the bean must have code to reacquire these connections when the bean is reactivated. Otherwise, there are NullPointerExceptions when the application tries to reuse the connections.

 

Symptom... org.omg.CORBA.BAD_PARAM: Servant is not of the expected type. minor code... 4942F21E completed: No

This error can be returned to a client program when the program attempts to execute an EJB method.

Typically this problem is caused by a mismatch between the interface definition and implementation of the client and server installations, respectively.

Another possible cause is when an appserver is set up to use a single class loading scheme. If an application is uninstalled while the application server remains active, the classes of the uninstalled application are still loaded in the application server. If you change the application, redeploy and reinstall it on the application server, the previously loaded classes become back level. The back level classes cause a code version mismatch between the client and the server.

To correct this problem...

1. Change the appserver class loading scheme to multiple.
2. Stop and restart the appserver and try the operation again.
3. Make sure the client and server code version are the same.

 

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