JPA的配置檔案要放在類路徑下的META-INF下，預設命名為persistence.xml。

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">

    <!--
        transaction-type有兩個取值：
                            RESOURCE_LOCAL：本地事務管理，當只用一個數據庫時選擇這個
                            JTA:分散式事務管理，當資料庫採用分散式時使用
    
 
-->
    <persistence-unit name="myJpa" transaction-type="RESOURCE_LOCAL">
        <!--jpa的實現方式-->
        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>


        <!--可選配置-->
        <properties>
            <!--配置資料庫資訊-->
            <
 
property name="javax.persistence.jdbc.user" value="root"/>
            <property name="javax.persistence.jdbc.password" value="123456"/>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
            <property name="javax.persistence.jdbc.url" value
 
="jdbc:mysql://localhost:3306/jpa"/>


            <!--配置jpa實現方(hibernate)的配置資訊-->
            <property name="hibernate.show_sql" value="true"/>
            <property name="hibernate.hbm2ddl.auto" value="update"/>
        </properties>
    </persistence-unit>
</persistence>

相關maven依賴：

    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-entitymanager -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>5.0.7.Final</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-c3p0</artifactId>
            <version>5.0.7.Final</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>
    </dependencies>