9 Oracle TopLink

This chapter describes issues associated with Oracle TopLink. It includes the following topics:

9.1 General Issues and Workarounds

This section describes general issue and workarounds. It includes the following topic:

9.1.1 TopLink Object-Relational Issues

This section contains information on the following issues: Cannot set EclipseLink log level in WLS System MBean Browser

Use Oracle Enterprise Manager to set the EclipseLink log level; do not use the WLS System MBean Browser to complete this action. Incorrect outer join SQL on SQLServer2005

TopLink generates incorrect outer join for SQL Server v2005. The outer join syntax generated is correct for earlier versions of this database. To work around this limitation, reconfigure the database compatibility (refer to the SQLServer documentation for details). Alternatively, you can use a custom TopLink database platform. UnitOfWork.release() not Supported with External Transaction Control

A unit of work synchronized with a Java Transaction API (JTA) will throw an exception if it is released. If the current transaction requires its changes to not be persisted, the JTA transaction must be rolled back.

When in a container-demarcated transaction, call setRollbackOnly() on the EJB/session context:

public class MySessionBean
{    @Resource 
    SessionContext sc;
    public void someMethod()

When in a bean-demarcated transaction then you call rollback() on the UserTransaction obtained from the EJB/session context:

public class MySessionBean implements SomeInterface 
    SessionContext sc;
    public void someMethod() 
} Returning Policy for UPDATE with Optimistic Locking

The returning policy, which allows values modified during INSERT and UPDATE to be returned and populated in cached objects, does not work in conjunction with numeric version optimistic locking for UPDATE. The value returned for all UPDATE operations is 1 and does not provide meaningful locking protection.

Do not use a returning policy for UPDATE in conjunction with numeric optimistic locking.

The use of returning policy for INSERT when using optimistic locking works correctly. JDBC Drivers returning Timestamps as Strings

TopLink assumes that date and time information returned from the server will use Timestamp. If the JDBC driver returns a String for the current date, TopLink will throw an exception. This is the case when using a DB2 JDBC driver.

To work around this issue, consider using a driver that returns Timestamp (such as COM.ibm.db2.jdbc.app.DB2Driver) or change the policy to use local time instead of server time.

Another option is to use a query re-director on the ValueReadQuery used by the platform:

ValueReadQuery vrq = new ValueReadQuery(
    "SELECT to_char(sysdate, 'YYYY-MM-DD HH:MM:SS.SSSSS') FROM DUAL"
vrq.setRedirector(new TSQueryRedirector());
class TSQueryRedirector implements QueryRedirector 
    public Object invokeQuery(DatabaseQuery query, Record arguments, Session session)
        String value = (String)session.executeQuery(query);
        return ConversionManager.getDefaultManager().convertObject(
            value, java.sql.Timestamp.class
} Unit of Work does not add Deleted Objects to Change Set

When accessing the change set of a Unit of Work to determine what has changed, objects that are pending deletion (such as uow.deleteObject( ) and uow.deleteAllObjects( )) will not be returned from the result set.

The objects pending deletion are only available through the Unit of Work getDeletedObjects call.

9.1.2 TopLink Workbench Issues

This section contains information on the following issues: User Interface Issue

When running TopLink Mapping Workbench using JDK 1.7, dialogs with a group box containing check boxes or radio buttons may display duplicated or truncated group box titles. There is no loss of functionality, and you should proceed as usual. Accessibility

Due to an issue with IBM JDK 1.6, if NullPointExecption error dialog is generated when saving a file, the error dialog window is not in focus. Running the TopLink Workbench on Windows OS

Due to an issue with certain configurations and versions of Windows operating systems, users that launch the TopLink Workbench with the workbench.cmd file may receive a dialog that states: Could not find the main class. This occurs because the classpath specified contains a directory path which has periods in it. The workaround is to rename the offending directory or change the classpath to use directory paths which do not contain periods.

9.1.3 Oracle Database Extensions with TopLink

This section contains information on the following issue: Template JAR for Spatial and XDB Support in Oracle WebLogic Server

To fully support Oracle Spatial and Oracle XDB mapping capabilities (in both standalone Oracle WebLogic Server and the Oracle JDeveloper integrated WebLogic Server), you must use the toplink-spatial-template.jar and toplink-xdb-template.jar to extend the WebLogic Server domain to support Oracle Spatial and XDB, respectively.

To extend your WebLogic Server domain:

  1. Download the toplink-spatial-template.jar (to support Oracle Spatial) and toplink-xdb-template.jar (to support Oracle XDB) files from:

  2. Use Table 9-1, "To Support Oracle Spatial" or Table 9-2, "To Support Oracle XDB" to determine which files to copy.

    Table 9-1 To Support Oracle Spatial

    Copy this file From...Foot 1  To...Foot 2 




    Footnote 1 These are the default locations. Your actual location may vary depending on your specific environment, installed options, and version.

    Footnote 2 When using Oracle JDeveloper integrated WebLogic Server, the <WEBLOGIC_HOME> is located within the <JDEVELOPER_HOME> directory.

    Table 9-2 To Support Oracle XDB

    Copy this file From...Foot 1  To...Foot 2 










      ori18n-mapping.jarFoot 3 



    Footnote 1 These are the default locations. Your actual location may vary depending on your specific environment, installed options, and version.

    Footnote 2 When using Oracle JDeveloper integrated WebLogic Server, the <WEBLOGIC_HOME> is located within the <JDEVELOPER_HOME> directory.

    Footnote 3 Use orai18n-mapping.jar for Oracle Database 11.2 and higher.


    Although the actual JAR file may be named differently in your From directory, the file must be named as shown, when copied to the To directory.

  3. Launch the Config Wizard (<WEBLOGIC_HOME>/common/bin/config.sh (or .bat).

  4. Select Extend an existing WebLogic domain.

  5. Browse and select your WebLogic Server domain.

    When using JDeveloper with integrated WebLogic Server, the typical WebLogic Server domain location may be similar to:

    • In Windows environments: %APPDATA%\JDeveloper\systemXX.XX.XX.XX\DefaultDomain

      where XX.XX.XX.XX is the unique number of the product build.

      For Windows platforms, you must enable the Show hidden files and folders folder option.

    • In non-Windows environments, the default location is under the current user's default home directory: <$Home>/DefaultDomain

    Refer to the Oracle JDeveloper documentation for details.

  6. Select Extend my domain using an existing extension template.

  7. Browse and select the required template JAR (toplink-spatial-template.jar for Oracle Spatial, toplink-xdb-template.jar for Oracle XDB).

  8. Complete the remaining pages of the wizard.

9.1.4 Allowing Zero Value Primary Keys

By default, EclipseLink interprets zero as null for primitive types that cannot be null (such as int and long) causing zero to be an invalid value for primary keys. You can modify this setting by using the allow-zero-id property in the persistence.xml file. Valid values are:

  • true – EclipseLink interprets zero values as zero. This permits primary keys to use a value of zero.

  • false (default) – EclipseLink interprets zero as null.

Refer the EclipseLink User's Guide at http://wiki.eclipse.org/EclipseLink/UserGuide for more information.

9.1.5 Managed Servers on Sybase with JCA Oracle Database Service

When using a JCA service with the Oracle Database adapter in a cluster to perform database operations on a Sybase database, the managed nodes in the cluster process the messages and may attempt to perform duplicate operations.

Because supported versions of Sybase do not support Oracle TopLink record locking, Sybase allows the duplicate operation attempts.

9.1.6 Logging Configuration with EclipseLink Using Container Managed JPA

By default, EclipseLink users in container managed JPA will use the Oracle WebLogic Server logging options to report all log messages generated by EclipseLink. Refer to "Configuring WebLogic Logging Services" in Oracle® Fusion Middleware Configuring Log Files and Filtering Log Messages for Oracle WebLogic Server.

To use the EclipseLink native logging configuration, add the following property to your persistence.xml file:

<property name="eclipselink.logging.logger" value="DefaultLogger"/> 

9.1.7 Grid Cache requires CacheLoader

An oracle.eclipselink.coherence.integrated.EclipseLinkJPACacheLoader must be configured for entities configured as Grid Cache to ensure the necessary TopLink Grid wrapper class is generated.