使用Spring 3 + Hibernate JPA时，发现JPA带注释的类

Question

I have a web application using the Spring 3 + Hibernate JPA stack.

I would like to know if there is a way to have Hibernate to automatically discover @Entity annotated classes, so that I don't have to list them in the persistence.xml file. My @Entity annotated classes "live" in a separate jar, located in the WEB-INF/lib of my web application.

This is a snippet from my Spring configuration file:

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
   <property name="persistenceUnitName" value="mypersistence"/>
   <property name="dataSource" ref="dataSource"/>
   <property name="jpaVendorAdapter">
       <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
           <property name="showSql" value="true"/>
           <property name="generateDdl" value="true"/>
           <property name="databasePlatform" value="org.hibernate.dialect.DerbyDialect"/>
       </bean>
   </property>
</bean>

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="org.apache.derby.jdbc.ClientDriver"/>
    <property name="url" value="jdbc:derby://localhost:1527/library;create=true"/>
    <property name="username" value="app"/>
    <property name="password" value="app"/>
</bean>

<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>

<bean id="persistenceAnnotation" class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>

Answer 1

You can put the persistence.xml file inside the jar where your entities live. Don't need to specify anything then, it works automagically.

Answer 2

you can also specify your @Entity annotated classes in applicationContext.xml like this

<property name="packagesToScan">
     <list>
        <value>com.vattikutiirf.nucleus.domain</value>
        <value>com.vattikutiirf.nucleus.domain.generated.secondtime</value>
     </list>
  </property>

Answer 3

The separate jar files to scan for entities are specified using <jar-file> elements in persistence.xml . So, if you entities are located in /WEB-INF/lib/entities.jar , you need

<jar-file>lib/entities.jar</jar-file>