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openejb embedded container cannot find persistence.xml

Posted by: admin December 28, 2021 Leave a comment


I am using openEjb in embedded mode to test a stateless session bean, which has an injected EntityManager. However, when I run the test, it fails because it could not initialize the application. When I see the console I can also see an error related to not being able to find persistence.xml

Note: I tried putting WebContent, as well as META-INF in the classpath, but that does not help either.


There is something very strange about resource lookups when using openejb + eclipse.

  1. I added WebContent to source folders. I stopped getting the persistence.xml error, but now I get an error which suggests that openejb could not find any managed resource
  2. I added WebContent to source folders, but with a different output folder (using allow output folders for source folders), and the persistence.xml error starts occuring again
  3. I copied META-INF into ‘test’, which is the source folder for all tests, and everything runs fine
  4. Regarding points 1, and 2, teh issue seems to be the fact that WEB-INF also gets included as part of WebContent. If I exclude WEB-INF, then again openejb can find persistence.xml in the test and the test runs fine

I am honestly clueless about what is happening.

I am pasting all the relevant errors and code below.

Error stack from failing JUnit test in Eclipse

org.apache.openejb.OpenEjbContainer$InvalidApplicationException: org.apache.openejb.config.ValidationFailedException: Module failed validation. AppModule(name=)
    at org.apache.openejb.OpenEjbContainer$Provider.createEJBContainer(OpenEjbContainer.java:273)
    at javax.ejb.embeddable.EJBContainer.createEJBContainer(EJBContainer.java:56)
    at javax.ejb.embeddable.EJBContainer.createEJBContainer(EJBContainer.java:43)
    at com.diycomputerscience.slides.service.SlideServiceTest.setUp(SlideServiceTest.java:45)
    at junit.framework.TestCase.runBare(TestCase.java:128)
    at junit.framework.TestResult$1.protect(TestResult.java:106)
    at junit.framework.TestResult.runProtected(TestResult.java:124)
    at junit.framework.TestResult.run(TestResult.java:109)
    at junit.framework.TestCase.run(TestCase.java:120)
    at junit.framework.TestSuite.runTest(TestSuite.java:230)
    at junit.framework.TestSuite.run(TestSuite.java:225)
    at junit.framework.TestSuite.runTest(TestSuite.java:230)
    at junit.framework.TestSuite.run(TestSuite.java:225)
    at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:130)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.apache.openejb.config.ValidationFailedException: Module failed validation. AppModule(name=)
    at org.apache.openejb.config.ReportValidationResults.deploy(ReportValidationResults.java:82)
    at org.apache.openejb.config.AppInfoBuilder.build(AppInfoBuilder.java:264)
    at org.apache.openejb.config.ConfigurationFactory.configureApplication(ConfigurationFactory.java:696)
    at org.apache.openejb.OpenEjbContainer$Provider.createEJBContainer(OpenEjbContainer.java:267)
    ... 18 more

My console output:

Apache OpenEJB 4.0.0-beta-2    build: 20120115-08:26
INFO - openejb.home = /home/user/workspace/wwald/slides
INFO - openejb.base = /home/user/workspace/wwald/slides
INFO - Using 'javax.ejb.embeddable.EJBContainer=true'
INFO - Configuring Service(id=Default Security Service, type=SecurityService, provider-id=Default Security Service)
INFO - Configuring Service(id=Default Transaction Manager, type=TransactionManager, provider-id=Default Transaction Manager)
INFO - Inspecting classpath for applications: 38 urls. Consider adjusting your exclude/include.  Current settings: openejb.deployments.classpath.exclude='', openejb.deployments.classpath.include='.*'
INFO - Found EjbModule in classpath: /home/user/workspace/wwald/slides/build/classes
INFO - Searched 38 classpath urls in 2000 milliseconds.  Average 52 milliseconds per url.
INFO - Beginning load: /home/user/workspace/wwald/slides/build/classes
INFO - Configuring enterprise application: /home/user/workspace/wwald/slides
INFO - Configuring Service(id=Default Stateless Container, type=Container, provider-id=Default Stateless Container)
INFO - Auto-creating a container for bean SlideService: Container(type=STATELESS, id=Default Stateless Container)
INFO - Configuring Service(id=Default Managed Container, type=Container, provider-id=Default Managed Container)
INFO - Auto-creating a container for bean com.diycomputerscience.slides.service.SlideServiceTest: Container(type=MANAGED, id=Default Managed Container)
INFO - Dumping Generated ejb-jar.xml to: /tmp/ejb-jar-5804778531295096416slides.xml
INFO - Dumping Generated openejb-jar.xml to: /tmp/openejb-jar-2921830618491817127slides.xml
ERROR - FAIL ... SlideService:  Missing required persistence.xml for @PersistenceContext ref "em" to unit "entities"
ERROR - Invalid EjbModule(name=slides, path=/home/user/workspace/wwald/slides/build/classes)
INFO - Set the 'openejb.validation.output.level' system property to VERBOSE for increased validation details.
WARN - configureApplication.loadFailed

The Stateless Session Bean:

public class SlideService {
    @PersistenceContext(unitName="entities", type=PersistenceContextType.TRANSACTION)
    private EntityManager em;

    //various business methods not shown for brevity


<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="entities">
            <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema" />

The JUnit test case:

public class SlideServiceTest extends TestCase {

    private SlideService slideService;

    public SlideServiceTest(String name) {

    protected void setUp() throws Exception {

        final Properties p = new Properties();
        p.put("myds", "new://Resource?type=DataSource");
        p.put("myds.JdbcDriver", "org.hsqldb.jdbcDriver");
        p.put("myds.JdbcUrl", "jdbc:hsqldb:mem:slidedb");

        EJBContainer ejbContainer = EJBContainer.createEJBContainer();
        Object oSlideService = ejbContainer.getContext().lookup("java:global/slides/SlideService");
        this.slideService = (SlideService)oSlideService;

    //not showing test methods for brevity, since the code fails in setUp itself

I received the same exception and the problem was that two persistence.xml were on the classpath of OpenEJB.

When I removed one of them, the problem was solved.

The exception message is not helpful here on part of OpenEJB, but if you debug into org.apache.openejb.config.Appmodule‘s hasFailures() or hasErrors() method, you can see more useful info in EjbModule.getValidation() calls! (Version 4.0.0).


Maven creates directory structure for web projects as shown below:


To resolve your issue you should create dir [META-INF] under directory [resources] and place persistence.xml there.


The main problem here is that while running junit, JUnit starts to think the WAR file as JAR file hence tries to find the persistance.xml in META-INF at root, while in WAR file the META-INF gets created inside WebContent folder. I simply created a symbolic link in the src folder pointing to the original META-INF. And voilla……………it worked. 🙂