环境：Windows 7，NetBean 6.9（包括GlassFish v3，Java EE 6），MySQL服务器。
我已在MySQL数据库中创建了表，并使用NetBean的功能通过右键单击项目并选择“从数据库创建实体”（如果措辞不正确，请见谅，因为我的NetBean是日语版）。
这将创建实体。
现在我想测试是否可以通过实体管理器访问数据库。
Tmp.java
package local.test.tmp;
import Resources.Users;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.EntityManager;
import javax.persistence.Query;
import java.util.List;
/**
*
* @author m-t
*/
public class Tmp {
private static EntityManagerFactory factory;
private static final String WEB_PU = "WebApplication1PU";
public static void main(String args[]) {
factory = Persistence.createEntityManagerFactory(WEB_PU);
EntityManager em = factory.createEntityManager();
//read existing entries and write to concole
Query q = em.createQuery("select * from users");
List<Users> userList = q.getResultList();
for(Users u : userList) {
System.out.println(u);
}
}
}
persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" 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_2_0.xsd">
<!-- orignal
<persistence-unit name="WebApplication1PU" transaction-type="JTA">
<jta-data-source>masatoJNDI</jta-data-source>
<properties/>
</persistence-unit>
-->
<persistence-unit name="WebApplication1PU" transaction-type="JTA">
<jta-data-source>masatoJNDI</jta-data-source>
<properties>
<property name="toplink.jdbc.user" value="masato" />
<property name="toplink.jdbc.password" value="foobar" />
</properties>
</persistence-unit>
</persistence>
当我运行Tmp.java时，我发现它失败了：
factory = Persistence.createEntityManagerFactory(WEB_PU);
错误信息：
Exception in thread "main" javax.persistence.PersistenceException: No Persistence
provider for EntityManager named WebApplication1PU
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:84)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54)
at local.test.tmp.Tmp.main(Tmp.java:24)
我已经检查了测试代码中持久化单元“WebApplication1PU”的拼写，与persistence.xml文件匹配，并且是正确的。
persistence.xml位于...它是用日语编写的，我不知道如何用英语表达 :(
让我试试...
project
|-------web page
|-------test package
|-------lib
|-------enterprise bean
|-------*** file //blah file, I can't translate..
|-----MNIFEST.MF
|-----faces-cofig.xml
|-----persistence.xml //HERE!!
由于工厂尝试在persistence.xml中定位持久化单元失败，我完全感到困惑。 我应该核实有什么吗？
如果需要更多澄清，请告诉我。
更新
我已经尝试了建议的可能解决方案，但是没有成功... 返回相同的错误消息。 是的，Netbean 6.9默认提供程序是Toplink。
我所做的:
将提供程序添加到persistence.xml中
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" 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_2_0.xsd">
<persistence-unit name="NoJSFPU" transaction-type="JTA">
<provider>oracle.toplink.essentials.PersistenceProvider</provider>
<jta-data-source>masatoJNDI</jta-data-source>
<properties>
<property name="toplink.jdbc.url" value="jdbc:mysql://localhost:3306/mytest"/>
<property name="toplink.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="toplink.jdbc.user" value="masato" />
<property name="toplink.jdbc.password" value="mocha123" />
</properties>
</persistence-unit>
</persistence>
看起来大多数人都在我的情况下取得了成功。我现在开始考虑可能是我运行测试文件的方式或文件所在位置有问题？
我从Netbean执行的Tmp.java位于：
project
|------web page
|------source package
| |-----------local.test.session
|-----------local.test.tmp
|------------------Tmp.java //HERE
我不确定这是否重要。
更新2
我已经将包含toplink-essential.jar和toplink-essential-agent.jar的toplink lib添加到我的项目的lib目录中，现在除了原来的错误之外，我还遇到了新的错误，但我相信我已经接近解决问题了。
看起来persistence.xml文件中的version属性有问题...???
Exception in thread "main" javax.persistence.PersistenceException: No Persistence provider for EntityManager named WebApplication1PU: Provider named oracle.toplink.essentials.PersistenceProvider threw unexpected exception at create EntityManagerFactory:
oracle.toplink.essentials.exceptions.PersistenceUnitLoadingException
Local Exception Stack:
Exception [TOPLINK-30005] (Oracle TopLink Essentials - 2.0.1 (Build b09d-fcs (12/06/2007))): oracle.toplink.essentials.exceptions.PersistenceUnitLoadingException
Exception Description: An exception was thrown while searching for persistence archives with ClassLoader: sun.misc.Launcher$AppClassLoader@f6a746
Internal Exception: Exception [TOPLINK-30004] (Oracle TopLink Essentials - 2.0.1 (Build b09d-fcs (12/06/2007))): oracle.toplink.essentials.exceptions.PersistenceUnitLoadingException
Exception Description: An exception was thrown while processing persistence.xml from URL: file:/C:/Users/m-takayashiki/Documents/NetBeansProjects/NoJSF/build/web/WEB-INF/classes/
Internal Exception:
(1. cvc-complex-type.3.1: Value '2.0' of attribute 'version' of element 'persistence' is not valid with respect to the corresponding attribute use. Attribute 'version' has a fixed value of '1.0'.)
at oracle.toplink.essentials.exceptions.PersistenceUnitLoadingException.exceptionSearchingForPersistenceResources(PersistenceUnitLoadingException.java:143)
at oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider.createEntityManagerFactory(EntityManagerFactoryProvider.java:169)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:110)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83)
at local.test.tmp.Tmp.main(Tmp.java:24)
更新 3
经过一些研究，发现版本号需要符合1.0标准，所以我应用了修复程序，但是出现了新的错误。
<?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="NoJSFPU" transaction-type="JTA">
<provider>oracle.toplink.essentials.PersistenceProvider</provider>
<jta-data-source>masatoJNDI</jta-data-source>
<class>local.test.session.Addresses</class>
<class>local.test.session.Users</class>
<properties>
<property name="toplink.jdbc.url" value="jdbc:mysql://localhost:3306/mytest"/>
<property name="toplink.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="toplink.jdbc.user" value="masato" />
<property name="toplink.jdbc.password" value="mocha123" />
</properties>
</persistence-unit>
</persistence>
很奇怪，因为我已经在上面的persistence.xml中指定了class :(
Exception in thread "main" javax.persistence.PersistenceException: Exception [TOPLINK-7060]
(Oracle TopLink Essentials - 2.0.1 (Build b09d-fcs (12/06/2007))): oracle.toplink.essentials.exceptions.ValidationException
Exception Description: Cannot acquire data source [masatoJNDI].
Internal Exception: javax.naming.NoInitialContextException: Need to specify class name in
environment or system property, or as an applet parameter, or in an application resource
file: java.naming.factory.initial
更新 4
我认为这并不算是“已解决”，但是经过长时间的尝试后，我决定在网页应用程序中运行我的测试代码，而不是从Netbean单独运行。由于GlassFish没有提供web.xml，所以我不得不自己创建它。(我看到了sun-web.xml，但它不是替代品) 然后创建Servlet，在web.xml中定义映射，并将我的测试代码片段添加到Servlet中，在浏览器上进行测试。它工作了，成功地从数据库中获取数据。
我想知道为什么当我尝试从Netbean运行只有Tmp.java（我的测试文件）时它不能工作...