PersistenceUnitInfo implementation in EclipseLink

Question

EntityManagerFactory can be created without a persistence unit xml using

org.eclipse.persistence.jpa.PersistenceProvider {
 public EntityManagerFactory createContainerEntityManagerFactory(PersistenceUnitInfo info,
                                                                    java.util.Map properties)
    }

but what is the implementation class of javax.persistence.spi.PersistenceUnitInfo in eclipselink

daizhuoxian · Answer 1 · 2013-12-08T06:07:37.430

I am struggling on this problem too. I think that a PersistenceUnitInfo must be provided by the container(i.e. Application Server). It means that Eclipselink do not create one itself. If you are using Spring ORM, it uses a DefaultPersistenceUnitManager and call its obtainPersistenceUnitInfo(String unitName) method to get a instance of PersistenceUnitInfo. The unitName must be defined in persistence.xml. This means that you still needs an xml file.

By digging into the source code of Spring ORM, I found that Spring provides several implementations of PersistenceUnitInfo. In fact they are generally a Java Bean. You may be interested in SmartPersistenceInfo, MutablePersistenceInfo and SpringPersistenceUnitInfo. View them on Github.

EDIT:

I found the implementation of Eclipselink: It's SEPersistenceUnitInfo in org.eclipse.persistence.internal.jpa.deployment. Also found the method that reads every persistence unit in the configuration xml file.

    public static Set<SEPersistenceUnitInfo> getPersistenceUnits(ClassLoader loader, Map m, List<URL> jarFileUrls) {
    String descriptorPath = (String) m.get(PersistenceUnitProperties.ECLIPSELINK_PERSISTENCE_XML);
    if(descriptorPath == null) {
        descriptorPath = System.getProperty(PersistenceUnitProperties.ECLIPSELINK_PERSISTENCE_XML, PersistenceUnitProperties.ECLIPSELINK_PERSISTENCE_XML_DEFAULT);
    }
    Set<Archive> archives = findPersistenceArchives(loader, descriptorPath, jarFileUrls);
    Set<SEPersistenceUnitInfo> puInfos = new HashSet();
    try {
        for(Archive archive : archives) {
            List<SEPersistenceUnitInfo> puInfosFromArchive = getPersistenceUnits(archive, loader);
            puInfos.addAll(puInfosFromArchive);
        }
    } finally {
        for(Archive archive : archives) {
            archive.close();
        }
    }
    return puInfos;
}

score 1 · Answer 2 · answered Aug 05 '15 at 00:56

1

Java EE platform spec 6 says : the container is responsible for finding persistence.xml condensing the information into PersistenceUnitInfo and supplying that with a call to createContainerEntityManagerFactory.

answered Aug 05 '15 at 00:56

tomk

31
5

score 0 · Answer 3 · answered Jul 02 '13 at 14:37

0

PersistenceUnitInfo is defined by the Spec, refer to the JPA spec code or JavaDoc for its implementation.

http://www.eclipse.org/eclipselink/api/2.5/javax/persistence/spi/PersistenceUnitInfo.html

answered Jul 02 '13 at 14:37

James

17,965
11
91
146

Not clear about, how to create instance of PersistenceUnitInfo ? JPA spec define that it is implemented by container . Is there any example code about to create entitymanager without persistence xml using `createContainerEntityManagerFactory(PersistenceUnitInfo info,java.util.Map properties)` – user225928 Jul 03 '13 at 12:01
You need to define your own class that implements the interface. – James Jul 03 '13 at 13:10
May you define small code example snippet to create entitymanager without persistence xml using `createContainerEntityManagerFactory(PersistenceUnitInfo info,java.util.Map properties)` – user225928 Jul 03 '13 at 18:25

PersistenceUnitInfo implementation in EclipseLink

3 Answers3