persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1"
  xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="john" transaction-type="RESOURCE_LOCAL">

        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <class>po.Book</class>
        
        <properties>
            <!-- 标准配置方法，适用性高 -->
            <!-- 
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/test"/> 
            <property name="javax.persistence.jdbc.user" value="root"/> 
            <property name="javax.persistence.jdbc.password" value="123"/>
            <property name=“javax.persistence.jdbc.driver” value=“com.mysql.jdbc.Driver”/> 
            <property name="javax.persistence.schema-generation.database.action" value="drop-and-create"/>
            -->
            
            <!-- hibernate 的配置方法-->
            <property name="hibernate.connection.url" value="jdbc:oracle:thin:@10.211.55.3:1521:xe" />
            <property name="hibernate.connection.username" value="tom3" />
            <property name="hibernate.connection.password" value="123" />
            <property name="hibernate.connection.driver_class" value="oracle.jdbc.OracleDriver" />
            <property name="hibernate.dialect" value="org.hibernate.dialect.OracleDialect" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.format_sql" value="true"/>
             <property name="hibernate.hbm2ddl.auto" value="update"/> <!--create,create-drop,update,validate  -->
        </properties>
    </persistence-unit>
</persistence>