错误原因是什么“在类路径中找不到META-INF/persistence.xml”？

Question

包括所有necesaary排名靠前的lib仍然得到关于使用NetBeans 6.8

没有META-INF/persistence.xml中在类路径中运行example.java

以下错误。

的persistence.xml

<?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="MatdaanPU" transaction-type="JTA"> 
    <provider>oracle.toplink.essentials.PersistenceProvider</provider> 
    <jta-data-source>matdaan</jta-data-source> 
    <class>EntityBeans.Trial</class> 
    <exclude-unlisted-classes>true</exclude-unlisted-classes> 
    <properties> 
     <property name="toplink.ddl-generation" value="create-tables"/> 
    </properties> 
    </persistence-unit> 
</persistence> 

---

Example.java

import java.util.List; 
import javax.persistence.EntityManager; 
import javax.persistence.EntityManagerFactory; 
import javax.persistence.Persistence; 
public class Example { 
    public Example() { 

     EntityManagerFactory emf=Persistence.createEntityManagerFactory("MatdaanPU"); 
     EntityManager em=emf.createEntityManager(); 
     List results = em.createNamedQuery("Trial.findById") 
    .setParameter("id", "1") 
    .getResultList(); 
     System.out.println("HI"); 
     System.out.println(results.get(1)); 
    } 

    public static void main(String args[]){ 
     Example e=new Example(); 

    } 
} 

---

目录结构

Root 
| 
| 
|----src 
|  | 
|  |----conf 
|   | 
|   |-----Manifest.MF 
|   |-----Persistence.xml 

Answer 1

认沽你的persistence.xml在src/META-INF文件夹中。

此外信件可能很重要。重命名Persistence.xml至persistence.xml