GlassFish 3.1.1的persistence.xml [英] persistence.xml with Glassfish 3.1.1

问题描述

我对玻璃鱼，JPA等非常陌生，在设置这些方面我遇到了很多问题。我打算做的是一个带有持久后端的简单RESTful服务。我使用glassfish3作为应用程序服务器，并且已经使用泽西库部署了一个简单的REST服务。现在我想通过JPA提供对数据库的访问。 Glassfish随JavaDB / derby和EclipseLink提供，是吗？所以，我想使用它： - ）

我在META-INF中创建了一个persistence.xml：

 <？xml version =1.0encoding =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 /持久性/ persistence_1_0.xsd> 
< persistence-unit name =myPUtransaction-type =JTA> 
< provider> org.eclipse.persistence.jpa.PersistenceProvider< / provider> 
< exclude-unlisted-classes> false< / exclude-unlisted-classes> 
<属性> 
< property name =javax.persistence.jdbc.drivervalue =org.apache.derby.jdbc.ClientDataSource/> <！ -  org.apache.derby.jdbc.EmbeddedDriver  - > 
< property name =javax.persistence.jdbc.urlvalue =jdbc：derby：// localhost：1527 / sample; create = true/> 
< property name =javax.persistence.jdbc.uservalue =APP/> 
< property name =javax.persistence.jdbc.passwordvalue =APP/> 
< property name =eclipselink.ddl-generationvalue =create-tables/> 
< / properties> 
< / persistence-unit> 
< /余辉> 
  

然后，我在资源中创建了一个字段，用于访问/存储som数据：

  @PersistenceUnit（unitName =myPU）
 EntityManagerFactory emf; 
  

但是emf始终为NULL： - （

）

我猜我的persistence.xml没有配置好。

如果有人有提示，我做错了什么， / p>

谢谢！

解决方案

这里是相应的配置：

$ ul

glassfish 3.1.1

内建JavaDB / derby数据库：jdbc / __ default

glassfish的JPA，它是eclipselink

（JAX RS：Jersey， li>

因此，您必须在src文件夹中创建文件夹META-INF，并将persistence.xml放在该文件夹中：

 <？xml version =1.0encoding =UTF-8？> 
< persistence version =1.0 
 xmlns =http://java.sun.com/xml/ns/persistence
 xmlns：xsi =http://www.w3.org/2001/XMLSchema-instance
 xsi：schemaLoc ation =http://java.sun.com/xml/ns/persistence 
 http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd\"> 
< persistence-unit name =myPUtransaction-type =JTA> 
< provider> org.eclipse.persistence.jpa.PersistenceProvider< / provider> 
< jta-data-source> jdbc / __ default< / jta-data-source> 
< exclude-unlisted-classes> false< / exclude-unlisted-classes> 
<属性> 
< property name =eclipselink.ddl-generationvalue =drop-and-create-tables/> 
< / properties> 
< / persistence-unit> 
< /余辉> 
  

我之前在WebContent的META-INF中创建了.xml，这是错误的。
您也不需要引用任何额外的库，因为您已经添加了glassfish模块。

现在我创建了一个JavaBean，在那里注入PersistenceUnit：

  @Stateless 
 public class StorageService {
 
 @PersistenceContext（unitName = myPU）
 EntityManager em; 
 
 ... 
} 
  

这个注入在Jersey-Servlets的资源类中：

  @Path（/ someres）
 @Produces（ MediaType.APPLICATION_XML）
 @Stateless 
 public class SomeRes {
 
 @EJB 
 StorageService storageService; 
 
 
} 
  

注射只能起作用如果这些类标记为@Stateless。

I am very new to glassfish, JPA and so on and I have really problems with setting that up. What I am planning to do is a simple RESTful service with a persistent backend. I am using glassfish3 as application server and already deployed a simple REST service with the jersey-library. Now I want to provide access to a database via JPA. Glassfish is shipped with JavaDB/derby and EclipseLink, is that right? So, I want to use that :-)

I created a persistence.xml in META-INF:

<?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="myPU" transaction-type="JTA">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <exclude-unlisted-classes>false</exclude-unlisted-classes>
    <properties>
      <property name="javax.persistence.jdbc.driver"   value="org.apache.derby.jdbc.ClientDataSource" /> <!-- org.apache.derby.jdbc.EmbeddedDriver -->
      <property name="javax.persistence.jdbc.url"      value="jdbc:derby://localhost:1527/sample;create=true" />
      <property name="javax.persistence.jdbc.user"     value="APP" />
      <property name="javax.persistence.jdbc.password" value="APP" />
      <property name="eclipselink.ddl-generation"      value="create-tables" />
    </properties>
  </persistence-unit>
</persistence>

Then I created a field in my resource, where I want to access/store som data:

@PersistenceUnit(unitName = "myPU")
EntityManagerFactory emf;

But "emf" is always NULL :-(

I guess that my persistence.xml is not configured appropriate.

Would be really glad if someone has a hint, what I am doing wrong...

thanks!

解决方案

I have the solution now for my problem. Here is the corresponding configuration:

• glassfish 3.1.1
• built-in JavaDB/derby database: jdbc/__default
• glassfish's JPA, which is eclipselink
• (JAX RS: Jersey, which is shipped with glassfish)

So, you have to create the folder "META-INF" wihtin your src folder and put the persistence.xml there:

<?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="myPU" transaction-type="JTA">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <jta-data-source>jdbc/__default</jta-data-source>
    <exclude-unlisted-classes>false</exclude-unlisted-classes>
    <properties>
        <property name="eclipselink.ddl-generation" value="drop-and-create-tables" />
    </properties>
  </persistence-unit>
</persistence>

I created the .xml previously in the META-INF of WebContent, and that is wrong. You also do not have to reference any additional libraries, since you have the glassfish modules added.

Now I have created a JavaBean, where I do inject the PersistenceUnit:

@Stateless
public class StorageService {

    @PersistenceContext(unitName = "myPU")
    EntityManager em;

...
}

And this one is injected in my Resource-Classes of the Jersey-Servlets:

@Path("/someres")
@Produces(MediaType.APPLICATION_XML)
@Stateless
public class SomeRes {

    @EJB
    StorageService storageService;

...
}

The injections do only work if the classes are marked as "@Stateless".

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