jpa persistence.xml的配置模板

<?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" />   
    <property name="hibernate.format_sql" value="true" /> 
   </properties>   
   
</persistence-unit>   
   
</persistence>