Persistence.xml 配置说明

<?xml version="1.0" encoding="UTF-8"?>

<persistence version="1.0"
xmlns:persistence="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 persistence_1_0.xsd ">


<!-- 
     Name属性用于定义持久化单元的名字 (name必选,空值也合法);
     transaction-type 指定事务类型(可选) 
-->
<persistence-unit name="unitName" transaction-type="JTA">


   <!-- 描述信息.(可选) -->
   <description> </description>

   <!-- javax.persistence.PersistenceProvider接口的一个实现类(可选) -->
   <provider>   </provider>

   <!-- Jta-data-source和 non-jta-data-source用于分别指定持久化提供商使用的JTA和/或non-JTA数据源的全局JNDI名称(可选) -->
   <jta-data-source>java:/MySqlDS</jta-data-source>
   <non-jta-data-source> </non-jta-data-source>

   <!-- 声明orm.xml所在位置.(可选) -->
   <mapping-file>product.xml</mapping-file>

   <!-- 以包含persistence.xml的jar文件为基准的相对路径,添加额外的jar文件.(可选) -->
   <jar-file>../lib/model.jar</jar-file>

   <!-- 显式列出实体类,在Java SE 环境中应该显式列出.(可选) -->
   <class>com.domain.User</class>
   <class>com.domain.Product</class>

   <!-- 声明是否扫描jar文件中标注了@Enity类加入到上下文.若不扫描,则如下:(可选) -->
   <exclude-unlisted-classes/>

   <!--   厂商专有属性(可选)   -->
   <properties>
    <!-- hibernate.hbm2ddl.auto= create-drop / create / update -->
    <property name="hibernate.hbm2ddl.auto" value="update" />
    <property name="hibernate.show_sql" value="true" />
   </properties>

</persistence-unit>
</persistence>

persistence.xml
2008-02-13 21:42

<?xml version="1.0" encoding="UTF-8"?>
<persistence 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" version="1.0">
    
    <!-- 
    persistence-unit name="EjbXmlMappingsPU" // 持久化单元名
    transaction-type="JTA(default)/RESOURCE_LOCAL" // 事务类型
    -->
<persistence-unit name="EjbXmlMappingsPU" transaction-type="JTA">
   <description></description> <!-- 描述 -->
   <provider>oracle.toplink.essentials.PersistenceProvider</provider> <!-- 指定一个持久化提供者 -->
   <jta-data-source>jdbc/MyDataSource</jta-data-source> <!-- 指定JTA数据源 -->
   <non-jta-data-source>jdbc/NonTxMyDataSource</non-jta-data-source> <!-- 指定非JTA数据源 -->
   <mapping-file>META-INF/my_queries.xml</mapping-file> <!-- 指定映射文件 -->
   <mapping-file>META-INF/my_entities.xml</mapping-file>
   <jar-file>my/my-classes.jar</jar-file> <!-- 指定托管类的附加JAR -->
   <class>myclass1</class> <!-- 明确列出的类 -->
   <class>myclass2</class>
   <exclude-unlisted-classes/> <!-- 使本地类不能被加到持久化单元中 -->
   <properties> <!-- 使用提供者属性 -->
    <property name="toplink.logging.level" value="FINE"/>
    <property name="toplink.cache.size.dafault" value="500"/>
   </properties>
</persistence-unit>

</persistence>