Database connection via JPA and JNDI

Master / Vertiefung Agile Methods and Open Source
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Database connection via JPA and JNDI
I have a problem to connect to my localdatabase via JNDI and tha Java JPA Persistence Unit usind EclipseLink.
The database with JPA only works fine. But when i try to connect via JNDI, there is no connection and our webapp says
‘HTTP Status 500 - com.vaadin.server.ServiceException: java.lang.NoClassDefFoundError: Could not initialize class com.fau.amos.team2.WoundManagement.WoundManagementUI’

I did the following:

  1. Changed my tomcat7 context.xml as described in lecture:
    Used the credentials of my local running postgresql server.

  2. Configured the persistance.xml of our webapp

	<jta-data-source>java:comp/env/jdbc/postgresql</jta-data-source>
	
	<class>com.fau.amos.team2.WoundManagement "..."</class> <!-- classes used for OR-Mapper -->
	
	        <exclude-unlisted-classes>false</exclude-unlisted-classes>
	<shared-cache-mode>NONE</shared-cache-mode>
	
	<properties>
 		<property name="eclipselink.logging.level" value="FINE"/>
 		<property name="eclipselink.ddl-generation" value="create-or-extend-tables"/>
 		<property name="eclipselink.ddl-generation.output-mode" value="database"/>
	</properties>
  1. Created a web.xml File for our webapp



testdb
persistence/em


jdbc/postgresql
javax.sql.DataSource
Container

  1. Tried to create an EntityManagerFactory:
    EntityManagerFactory emf = Persistence.createEntityManagerFactory(“testdb”);

Does anyone have an idea, why it doesnt connect to the database?

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Hi,

I have a feeling that JNDI is not directly responsible for your exception.

Are you sure your web.xml file is correct? Not in respect to JNDI but in respect to Vaadin. I think you are missing some important entries:
https://vaadin.com/book/-/page/application.environment.html

Usually, if your JNDI configuration doesn’t work you’ll get an exception as soon as you do the first access to the DataSource, but that wouldn’t be a NoClassDefFoundError. Maybe a NamingException.

  1. Can you be more specific? How were you able to test this if your application doesn’t even start?

Cheers
Hannes