javax.persistence jar is not loaded into tomcat - eclipse

Question

I'm trying to run JPA servlet on Tomcat 8.
From my servlet I call method of a class named QueryDB.class located in another Eclipse project (JPA project, not WEB project).
But tomcat throws
SEVERE: Servlet.service() for servlet [MyRESTService] in context with path [/AutomationWeb] threw exception [org.glassfish.jersey.server.ContainerException: java.lang.NoClassDefFoundError: javax/persistence/Persistence] with root cause
java.lang.ClassNotFoundException: javax.persistence.Persistence
at java.net.URLClassLoader$1.run(Unknown Source)
...
Exception is thrown at line EntityManagerFactory emf = Persistence.createEntityManagerFactory( "AutomationDB_JPA" ); in QueryDB.class
I'm using Eclipse Mars with Maven. I have EclipseLink in my pom.xml defined:
<dependency>
<groupId>org.eclipse.persistence</groupId>
<artifactId>eclipselink</artifactId>
<version>2.6.1</version>
</dependency>
I have following jars in my Application's WEB-INF/lib:
eclipselink-2.6.1.jar
javax.persistence-2.1.0.jar , it has javax/persistence/Persistence.class inside
There is no other SEVERE messages in the tomcat log.
What's wrong with this setup?
I also tried adding the persistence jar to apache-tomcat-8.0.28\lib , but got the same error.
Update: I moved Persistence.createEntityManagerFactory call to the servlet itself and got no classloader exception. So the question changes: why classloader used for QueryDB.class is different from servlet's classloader? Also, why classloader used in QueryDB.class does not see the Persistence.class, which is seen by the servlet's classloader?

Answer 1

Ok I've found a solution.
Excluded my JPA project from tomcat VM classpath
Converted my JPA project to the Utility project
Modified Deployment Assembly in my Web project properties so that it
will accept JPA project as .jar archive into WEB-INF/lib
I have no classloader exception anymore.