Configure the WSJPA persistence provider

Configure the WSJPA persistence provider

The WebSphere Application Server persistence provider (WSJPA) is the default provider for Java Persistence API (JPA) 2.0.

While built from the Apache OpenJPA persistence provider, the JPA for WAS persistence provider, WSJPA, contains the following enhancements and differences:
Static SQL support using the DB2 pureQuery feature
Access intent support
Enhanced tracing support
Version ID generation
WebSphere product-specific commands and scripts
Translated message files
Check in-memory caches for lazily loaded many-to-one or one-to-one relationships. Setting the wsjpa.BrokerImpl property to true specifies that the JPA implementation will attempt to load lazy fields from memory at run time if the foreign key data for the lazy fields are available. Use the following property:
<property name="wsjpa.BrokerImpl" value="checkCacheForLazyFields=true"/> 
This property can be useful in many scenarios. For example, assume we have a person entity, Person(A), that has a one-to-one relationship to another person, Person(B), and Person(B) is stored in the L2 data cache. If this property is set, when the JPA implementation finds Person(A), the foreign key that is loaded from Person(A) will be used to populate the relationship from Person(A) to Person(B).
The following table shows how the default values for the JPA for WAS persistence provider configuration properties are different from the Apache OpenJPA provider:

Property Apache OpenJPA default value JPA for WAS persistence provider default value
openjpa.Compatibility StrictIdentityValues=false StrictIdentityValues=true
openjpa.RuntimeUnenhancedClasses unsupported warn
openjpa.DynamicEnhancementAgent true false
open.jdbc.DriverDataSource auto simple
The OpenJPA compatibility property does not remove proxy types that OpenJPA generates for certain data types, especially date types such as GregorianCalendar. This omission can cause problems with deserialization. If a deserialization problem occurs, an error message, similar to the following message, is issued.
Error Message is:org.codehaus.jackson.map.JsonMappingException: 
Can not construct instance of org.apache.openjpa.util.java$util$GregorianCalendar$proxy, 
problem: no suitable creator method found at 
[Source: org.apache.http.conn.EofSensorInputStream@d83fbd5; line: 1, column: 4094]
In addition to the property overrides, the use of the default JPA for WAS persistence provider also implies the use of the following JPA for WAS classes which override the corresponding classes in Apache OpenJPA:
com.ibm.ws.persistence.jdbc.kernel.ConstraintUpdateManager;
com.ibm.ws.persistence.jdbc.kernel.WsJpaJDBCBrokerFactory;
com.ibm.ws.persistence.jdbc.sql.DB2Dictionary;
com.ibm.ws.persistence.jdbc.sql.OracleDictionary;
com.ibm.ws.persistence.jdbc.sql.SQLFactoryImpl;
com.ibm.ws.persistence.jdbc.sql.SQLServerDictionary;
com.ibm.ws.persistence.kernel.WsJpaBrokerImpl;
com.ibm.ws.persistence.kernel.WsJpaFinalizingBrokerImpl;
If no JPA provider is configured in the <provider> element of the persistence.xml file within an EJB module, the default JPA provider that is currently configured for this server is used. The product is packaged with the JPA for WAS persistence provider defined as the default provider. However, it is possible to override this default and specify a different default through the administrative console.

We can set your default persistence provider in one of two ways.

If we have a default persistence provider, default Java Transaction API (JTA) data source JNDI name, and default non-JTA data source JNDI name values that were set in the product before WAS v7.0, through the JVM properties, any change to these values through the administrative console override values that were set with the JVM properties.

These properties include com.ibm.websphere.jpa.default.provider, com.ibm.websphere.jpa.default.jta.datasource, and com.ibm.websphere.jpa.default.nonjta.datasource. Support for these properties has been deprecated. Any values that were set through these properties are displayed as default values on this panel. These values that are set through the administrative console panel overrides any values set through the JVM properties.

Tasks

Select the default JPA provider from a list of providers included with the product.

In the administrative console, click...
Servers > Server Types > WebSphere application servers > server > Container Services > Default Java Persistence API settings.
Select the JPA specification level to use for the provider.
Select Select a default persistence provider that is included with WAS.
Click the slider and select from the list.
Click Apply and save the configuration.

Specify an alternative default persistence provider through the administrative console.

In the administrative console, click...
Servers > Server Types > WebSphere application servers > server > Container Services > Default Java Persistence API settings.
Select the JPA specification level to use for the provider.
Select Specify an alternative default persistence provider.
Specify the fully qualified JPA implementation class name of a JPA persistence provider in the Default persistence provider field.
Click Apply and save the configuration.

Subtopics

Default Java Persistence API settings
To increase the portability of the applications, use this page to configure the default Java Persistence API (JPA) settings for applications running on this server instead of defining the <provider> element in each persistence unit in the applications.
Use third-party persistence providers
Java Persistence API (JPA) for WAS supports third-party persistence providers in their application server environment.
Default Java Persistence API settings
To increase the portability of the applications, use this page to configure the default Java Persistence API (JPA) settings for applications running on this server instead of defining the <provider> element in each persistence unit in the applications.
Use third-party persistence providers
Java Persistence API (JPA) for WAS supports third-party persistence providers in their application server environment.

Default Java Persistence API settings
WAS persistence providers
Use third-party persistence providers
Configure the default JTA and non-JTA data source JNDI names

Property	Apache OpenJPA default value	JPA for WAS persistence provider default value
openjpa.Compatibility	StrictIdentityValues=false	StrictIdentityValues=true
openjpa.RuntimeUnenhancedClasses	unsupported	warn
openjpa.DynamicEnhancementAgent	true	false
open.jdbc.DriverDataSource	auto	simple