what's wrong with my @PersistenceContext?

Question

I'm using Eclipse Juno, Glassfish 3.1.2, and MySQL 5.1.

I'm building a simple EJB & JSF application. I created the following eclipse projects:

appEAR <-- the EAR file
appEJB <-- contains UserService.java EJB
appJPA <-- contains UserDAO.java EJB, and User.java object
appWeb <-- contains index.jsp

It's just a skeleton right now, but I can deploy the app and see the index.jsp

Next, I tried to add the following to the UserDAO ...

@PersistenceContext
EntityManager em;

But then when the app tries to republish, it gives me the error:

'Publishing to GlassFish 3.1.2 at localhost...' has encountered a problem.  cannot Deploy appEar

There are no other details.

When I remove the two lines of @PersistenceContent code, the app deploys again.

Also, the persistence.xml file n the appJPA project is as follows:

<?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="appJPA">
            <class>app.model.User</class>
    </persistence-unit>
</persistence>

Please help ... what am I missing? I'm rather stuck.

At first site it seems that the "" is missing. I don't have to much experience with glassfish, but you can check the log files and see for other errors. — Olimpiu POP, Mar 05 '13 at 06:29
I think you have to add the transaction-type inside the persistence unit. also, does the user entity exist? — greenkode, Mar 05 '13 at 06:24

score 1 · Answer 1 · answered Mar 05 '13 at 08:48

Your persistence.xml is incomplete , you need to provide Connection properties to specify the provider ,which DB to connect etc

Heres an example using hibernate as the JPA provided

<persistence-unit name="educationPU"
    transaction-type="JTA">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <class>com.coe.jpa.StudentProfile</class>
    <properties>
        <property name="hibernate.connection.driver_class"
            value="com.mysql.jdbc.Driver" />
        <property name="hibernate.connection.url"
            value="jdbc:mysql://localhost:3306/COE" />
        <property name="hibernate.connection.username" value="root" />
        <property name="show_sql" value="true" />
        <property name="dialect" value="org.hibernate.dialect.MySQLDialect" />
    </properties>
</persistence-unit>

and heres a more Generic one

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>

score 0 · Answer 2 · answered Mar 05 '13 at 06:44

0

I don't use glassfish. But I think the reason is that you didn't specify any datasource in the persistence.xml. you should do this in it, which you can use jndi or other way. and second, you should define the entityManagerFactory bean in spring context xml file.

answered Mar 05 '13 at 06:44

OQJF

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also you should add transaction type if you want to use transaction. – OQJF Mar 05 '13 at 06:46

Gab · Answer 3 · 2013-03-05T13:42:11.447

0

Did you add the datasource in glasfish ? You will need to add the mysql jdbc drivers too. In Java EE, it's the persistence container (inside the server) which will create and manage the datasource for you.

See http://www.albeesonline.com/blog/2008/08/06/creating-and-configuring-a-mysql-datasource-in-glassfish-application-server/

edited Mar 05 '13 at 13:42

answered Mar 05 '13 at 08:28

Gab

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what's wrong with my @PersistenceContext?

3 Answers3