我是Java EE中的新手。这是我想要做的第一个项目,我有一个我无法解决的问题。我创建了三个项目:slowka-beans(EJB),slowka-persistance(JPA)和slowka-web(JSF)。部署它们后,我无法访问持久性单元 - EntityManager为空。一切正常 - 我可以创建bean,在其中实例化实体类并在JSF页面上显示它们。但是,我如何将它们存储在数据库中?我在JBoss站点上配置了MySQL数据库。JBoss 5.1上的Java EE bean中的空EntityManager
,我有以下看起来代码: LanguagesManager.java(在slowka豆)
@Stateless
public class LanguagesManager implements LanguagesManagerLocal {
@PersistenceContext(unitName="slowka-persistance")
private EntityManager em;
public LanguagesManager() {
System.out.println("LanguagesManagerBean constructor");
}
public String getWorking() {
if(em == null) {
System.out.println("Not working...");
return "Not working...";
} else {
System.out.println("It's ALIVE!");
return "It's ALIVE!";
}
}
}
的persistence.xml(slowka-持久性):
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
<persistence-unit name="slowka-persistance">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<jta-data-source>java:/PraktykiDS</jta-data-source>
<class>pl.edu.uj.sobczak.szymon.Language</class>
</persistence-unit>
</persistence>
服务器上部署没有按这没有任何例外。但我发现了以下警告在服务器的输出:
23:02:23,801 INFO [PersistenceUnitDeployment] Starting persistence unit persistence.unit:unitName=slowka.ear/slowka-persistance.jar#slowka-persistance
23:02:23,803 INFO [Ejb3Configuration] Processing PersistenceUnitInfo [
name: slowka-persistance
...]
23:02:23,804 WARN [Ejb3Configuration] Persistence provider caller does not implement the EJB3 spec correctly. PersistenceUnitInfo.getNewTempClassLoader() is null.
(... trimmed ...)
23:02:23,868 INFO [SessionFactoryObjectFactory] Bound factory to JNDI name: persistence.unit:unitName=slowka.ear/slowka-persistance.jar#slowka-persistance
23:02:23,868 WARN [SessionFactoryObjectFactory] InitialContext did not implement EventContext
每当我访问来自JSP LanguagesManager::getWorking()
我越来越“不工作......”输出。
我在Eclipse中创建了项目,JPA正在使用EclipseLink。我试过两种--EclipseLink 1.1.4和2.1.0,结果相同。
可以请你帮我吗?
我有完全相同的问题,并花了数天的时间来解决这个问题!最后你有没有运气?如果是这样,请你发表您的persistence.xml的副本,并从你的servlet/bean中relavent短代码片断 我对计算器的问题是[这里] [1] [1] :http://stackoverflow.com/questions/5373598/how-to-use-container-managed-transaction-cmt-with-jboss-as-6-hibernate-3-6-jp – willtardy 2011-03-21 11:13:08