没有名为EntityManager的持久性提供程序

Question

没有名为EntityManager的持久性提供程序我使用Toplink在meta-INF目录下使用相同的名称。然后我的代码调用它：EntityManagerFactory emfdb = Persistence.createEntityManagerFactory("agisdb");但是，我收到了以下错误消息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)下面是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。

Answer 1

确保persistence.xml文件位于目录中：<webroot>/WEB-INF/classes/META-INF