相关疑难解决方法(0)

我在META-INF目录下使用toplink,使用相同名称的persistence.xml.然后我让我的代码调用它:

EntityManagerFactory emfdb = Persistence.createEntityManagerFactory("agisdb");

但是,我收到以下错误消息

2009-07-21 09:22:41,018 [main] ERROR - No Persistence provider for EntityManager named agisdb
javax.persistence.PersistenceException: No Persistence provider for EntityManager named agisdb
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:89)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:60)

这是persistence.xml:

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="1.0">
    <persistence-unit name="agisdb">
        <class>com.agis.livedb.domain.AddressEntity</class>
        <class>com.agis.livedb.domain.TrafficCameraEntity</class>
        <class>com.agis.livedb.domain.TrafficPhotoEntity</class>
        <class>com.agis.livedb.domain.TrafficReportEntity</class>
        <properties>
            <property name="toplink.jdbc.url" value="jdbc:mysql://localhost:3306/agisdb"/>
            <property name="toplink.jdbc.driver" value="com.mysql.jdbc.Driver"/>
            <property name="toplink.jdbc.user" value="root"/>
            <property name="toplink.jdbc.password" value="password"/>
        </properties>
    </persistence-unit>
</persistence>

它应该在类路径中.然而,我得到了上述错误.