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[英]Sometimes getting PersistenceException: No Persistence provider for EntityManager
[英]Still getting PersistenceException: No Persistence provider for EntityManager
部署应用程序后,我得到了这样的异常:
Caused by: javax.persistence.PersistenceException: No Persistence provider for EntityManager named JavaAcademyUnit
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:85)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54)
at com.bogdankobylinsky.javaacademy.dao.impl.jpa.UserJPADAO.<init>(UserJPADAO.java:13)
,此行失败:
private EntityManager em = Persistence.createEntityManagerFactory("JavaAcademyUnit").createEntityManager();
JPA配置描述符persistanceance.xml文件位于正确的位置: ./ WEB-INF / classes / META-INF / persistence.xml ,其中包含:
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">
<persistence-unit name="JavaAcademyUnit" transaction-type="JTA">
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<jta-data-source>jdbc/__JavaAcademy</jta-data-source>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
<property name="hibernate.hbm2ddl.auto" value="update"/>
</properties>
</persistence-unit>
</persistence>
pom.xml包含:
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.6</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>4.3.1.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>4.3.1.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate.javax.persistence</groupId>
<artifactId>hibernate-jpa-2.0-api</artifactId>
<version>1.0.1.Final</version>
</dependency>
谢谢你的帮助!
最终,经过4个小时的谷歌搜索,我发现了原因:
Artifacts文件夹的根目录中必须带有所需的库的lib文件夹:
希望它会帮助某人。
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