Configuring the JPA default persistence provider
Two persistence providers are included in the product: JPA for WebSphere Application Server persistence provider and Apache OpenJPA persistence provider. The Java™ Persistence API (JPA) for WebSphere Application Server persistence provider is the default provider for the product. You can use one of these two providers, or a third-party persistence provider, as the default provider.
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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.
- 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:
This property can be useful in many scenarios. For example, assume you 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).<property name="wsjpa.BrokerImpl" value="checkCacheForLazyFields=true"/>
- The following table shows how the default values for the JPA for WebSphere Application Server
persistence provider configuration properties are different from the
Apache OpenJPA provider:
Table 1. Comparison . JPA for WebSphere Application Server persistence provider and Apache OpenJPA provider comparison Property Apache OpenJPA default value JPA for WebSphere Application Server persistence provider default value openjpa.Compatibility StrictIdentityValues=false StrictIdentityValues=true openjpa.RuntimeUnenhancedClasses unsupported warn openjpa.DynamicEnhancementAgent true false open.jdbc.DriverDataSource auto simple
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 previous property overrides, the use of the default JPA for WebSphere Application Server persistence provider also implies the use of the following JPA for WebSphere Application Server 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 Enterprise JavaBeans (EJB) module, the default JPA provider that is currently configured for this server is used. The product is packaged with the JPA for WebSphere Application Server persistence provider defined as the default provider. However, it is possible to override this default and specify a different default through the administrative console.
You can set your default persistence provider in one of two ways.