无法从Web应用程序使用EJB

Question

I have the next problem while trying to develope a REST app using JPA and EJB 's.

I have 3 projects in NetBeans (same workspace, just projects, not EAR or that weird stuff):

• One of them is a Java Application in which I created some entity classes from a database. Inside of the same project, I created other package containing the controller classes from the entities. I tested the project creating a java main class and using the controllers.

• The other project is a EJB module, it as simple as a package and the next class inside of it:

   package com.studentejb; import java.util.List; import javax.ejb.LocalBean; import javax.ejb.Stateless; import studentdao.StudentTO; import studentdao.StudentJpaController; @Stateless @LocalBean public class StudentEJB { private StudentJpaController studentDao = new StudentJpaController(); public List<StudentTO> findStudents() { return studentDao.findStudentTO(); } } 

As you can see, I imported the previous JAR project (the one with the entity's controllers). I also tested this EJB project with a java main class and it worked.

• The last project is a web application, as you can imagine I want to use the EJB modules of the previous project but I get the following errors while trying to enter to the resource http://localhost:8080/studentWeb/student/ :

   12:00:12,384 ERROR [io.undertow.request] (default task-2) UT005023: Exception handling request to /studentWeb/student/hola: com.google.common.util.concurrent.ExecutionError: java.lang.ExceptionInInitializerError at com.google.common.cache.LocalCache$Segment.get(LocalCache.java:2201) at com.google.common.cache.LocalCache.get(LocalCache.java:3937) at com.google.common.cache.LocalCache.getOrLoad(LocalCache.java:3941) at com.google.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4824) at org.jboss.weld.util.cache.LoadingCacheUtils.getCacheValue(LoadingCacheUtils.java:49) . . . at java.lang.Thread.run(Thread.java:745) Caused by: java.lang.ExceptionInInitializerError at studentdao.StudentJpaController.<init>(StudentJpaController.java:40) at com.studentejb.StudentEJB.<init>(StudentEJB.java:23) at com.studentweb.Resources.<init>(Resources.java:52) at com.studentweb.Resources$Proxy$_$$_WeldClientProxy.<init>(Unknown Source) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) . . . ... 58 more Caused by: javax.persistence.PersistenceException: Unable to locate persistence units at org.hibernate.jpa.HibernatePersistenceProvider.getEntityManagerFactoryBuilderOrNull(HibernatePersistenceProvider.java:99) at org.hibernate.jpa.HibernatePersistenceProvider.getEntityManagerFactoryBuilderOrNull(HibernatePersistenceProvider.java:86) at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:67) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39) at studentdao.EntityProvider.<clinit>(EntityProvider.java:20) ... 80 more Caused by: javax.persistence.PersistenceException: Invalid persistence.xml. Error parsing XML [line : -1, column : -1] : cvc-elt.1.a: Cannot find the declaration of element 'persistence'. at org.hibernate.jpa.boot.internal.PersistenceXmlParser.validate(PersistenceXmlParser.java:377) at org.hibernate.jpa.boot.internal.PersistenceXmlParser.loadUrl(PersistenceXmlParser.java:310) at org.hibernate.jpa.boot.internal.PersistenceXmlParser.parsePersistenceXml(PersistenceXmlParser.java:114) at org.hibernate.jpa.boot.internal.PersistenceXmlParser.doResolve(PersistenceXmlParser.java:104) at org.hibernate.jpa.boot.internal.PersistenceXmlParser.locatePersistenceUnits(PersistenceXmlParser.java:86) at org.hibernate.jpa.HibernatePersistenceProvider.getEntityManagerFactoryBuilderOrNull(HibernatePersistenceProvider.java:95) ... 85 more 

Here is the code of the web app (Resources.java):

@Path("/student")
public class Resources {
    @EJB
    private StudentEJB studentEjb;

    @Context
    private UriInfo context;

    public Resources() throws FileNotFoundException, IOException, NamingException {
        studentEjb = new StudentEJB();
    }

    @GET
    @Path("/")
    @Produces(MediaType.APPLICATION_JSON)
    public Response getJson() {
        return Response.ok(studentEjb.findStudents()).build();
    }
}

So I am using 2 JARs for the web project, the one with the EJB modules and the other with the entities and controllers..

Here is the persistence.xml generated by the JPA project:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://xmlns.jcp.org/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="studentJPAPU" transaction-type="RESOURCE_LOCAL">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <!-- <provider>org.hibernate.ejb.HibernatePersistence</provider> -->
    <class>studentjpa.Address</class>
    <class>studentjpa.Phone</class>
    <class>studentjpa.Student</class>
    <class>studentjpa.Email</class>
    <properties>
      <property name="javax.persistence.jdbc.url" value="jdbc:sqlserver://localhost:1433;databaseName=tca_student_db;integratedSecurity=true"/>
      <property name="javax.persistence.jdbc.user" value="xxxx"/>
      <property name="javax.persistence.jdbc.driver" value="com.microsoft.sqlserver.jdbc.SQLServerDriver"/>
      <property name="javax.persistence.jdbc.password" value="xxxx"/>
    </properties>
  </persistence-unit>
</persistence>

Thank you!

Answer 1

Caused by: javax.persistence.PersistenceException: Invalid persistence.xml. Error parsing XML [line : -1, column : -1] : cvc-elt.1.a: Cannot find the declaration of element 'persistence'.

Here :

<persistence version="2.0" xmlns="http://xmlns.jcp.org/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">

xmlns : http://xmlns.jcp.org/xml/ns/persistence doesn't match with the namespace in xsischemaLocation which is http://java.sun.com/xml/ns/persistence

Try to use the same in both :

<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">