I have very simple persistance.xml file:
<?xml version="1.0" encoding="UTF-8"?> <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"> <persistence-unit name="eventractor" transaction-type="RESOURCE_LOCAL"> <class>pl.michalmech.eventractor.domain.User</class> <class>pl.michalmech.eventractor.domain.Address</class> <class>pl.michalmech.eventractor.domain.City</class> <class>pl.michalmech.eventractor.domain.Country</class> <properties> <property name="hibernate.hbm2ddl.auto" value="validate" /> <property name="hibernate.show_sql" value="true" /> </properties> </persistence-unit> </persistence>
and it works.
But when I remove <class>
elements application doesn't see entities (all classes are annotated with @Entity
).
Is there any automatic mechanism to scan for @Entity
classes?
xml file. This file defines a persistence unit named OrderManagement, which uses a JTA-aware data source jdbc/MyOrderDB. The jar-file and class elements specify managed persistence classes: entity classes, embeddable classes, and mapped superclasses.
A JPA Persistence Unit is a logical grouping of user defined persistable classes (entity classes, embeddable classes and mapped superclasses) with related settings. Defining a persistence unit is optional when using ObjectDB, but required by JPA.
xml should be put in the EJB JAR's META-INF directory. If you package the persistence unit as a set of classes in a WAR file, persistence. xml should be located in the WAR file's WEB-INF/classes/META-INF directory.
The persistence. xml file must define a persistence-unit with a unique name in the current scoped classloader. The provider attribute specifies the underlying implementation of the JPA EntityManager. In JBoss AS, the default and only supported / recommended JPA provider is Hibernate.
The persistence.xml has a jar-file
that you can use. From the Java EE 5 tutorial:
<persistence> <persistence-unit name="OrderManagement"> <description>This unit manages orders and customers. It does not rely on any vendor-specific features and can therefore be deployed to any persistence provider. </description> <jta-data-source>jdbc/MyOrderDB</jta-data-source> <jar-file>MyOrderApp.jar</jar-file> <class>com.widgets.Order</class> <class>com.widgets.Customer</class> </persistence-unit> </persistence>
This file defines a persistence unit named OrderManagement
, which uses a JTA-aware data source jdbc/MyOrderDB
. The jar-file
and class
elements specify managed persistence classes: entity classes, embeddable classes, and mapped superclasses. The jar-file
element specifies JAR files that are visible to the packaged persistence unit that contain managed persistence classes, while the class
element explicitly names managed persistence classes.
In the case of Hibernate, have a look at the Chapter2. Setup and configuration too for more details.
EDIT: Actually, If you don't mind not being spec compliant, Hibernate supports auto-detection even in Java SE. To do so, add the hibernate.archive.autodetection
property:
<persistence-unit name="eventractor" transaction-type="RESOURCE_LOCAL"> <!-- This is required to be spec compliant, Hibernate however supports auto-detection even in JSE. <class>pl.michalmech.eventractor.domain.User</class> <class>pl.michalmech.eventractor.domain.Address</class> <class>pl.michalmech.eventractor.domain.City</class> <class>pl.michalmech.eventractor.domain.Country</class> --> <properties> <!-- Scan for annotated classes and Hibernate mapping XML files --> <property name="hibernate.archive.autodetection" value="class, hbm"/> <property name="hibernate.hbm2ddl.auto" value="validate" /> <property name="hibernate.show_sql" value="true" /> </properties> </persistence-unit>
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