JUnit, JPA, Hibernate and Postgres: How to unit test?
===

I've been stuck for a while now. I have searched a lot and I can't find the easiest way to unit test entity classes or JPA operations. I've found how to using Spring, Mockito and other things, but I can't find the simplest way using pure Java.

I have the following JUnit test: 

    public class ModelConverterTest {
        
        private static EntityManagerFactory emf;
        private static EntityManager em;
    
        
        public ModelConverterTest() {
        }
    
        @BeforeClass
        public static void setUpClass() throws Exception {
            emf = Persistence.createEntityManagerFactory("PU");
            em = emf.createEntityManager(); // Retrieve an application managed entity manager
        }
    
        @AfterClass
        public static void tearDownClass() throws Exception {
            em.close();
            emf.close(); //close at application end
        }
        
        @Before
        public void setUp() {
             ...    
        }
        
        @After
        public void tearDown() {
        }
    
        /**
         * Test of SIMModelToModel method, of class ModelConverter.
         */
        @Test
        public void testSIMModelToModel() {
            System.out.println("SIMModelToModel");
            SIMModel simModel = new PESMModel();
            simModel.addState(testState);
            Model expResult = null;
            Model result = ModelConverter.SIMModelToModel(em, simModel);
            assertTrue(expResult!=null);
            // TODO review the generated test code and remove the default call to fail.
            //fail("The test case is a prototype.");
        }
    }

and when running it, I get the following error:

    java.lang.ClassFormatError: Absent Code attribute in method that is not native or abstract in class file javax/persistence/PersistenceContextType
    	at java.lang.ClassLoader.defineClass1(Native Method)
    	at java.lang.ClassLoader.defineClass(ClassLoader.java:787)
    	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    	at java.net.URLClassLoader.defineClass(URLClassLoader.java:447)
    	at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
    	at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
    	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    	at java.security.AccessController.doPrivileged(Native Method)
    	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    	at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
    	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    	at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
    	at java.lang.Class.getDeclaredMethods0(Native Method)
    	at java.lang.Class.privateGetDeclaredMethods(Class.java:2442)
    	at java.lang.Class.getDeclaredMethods(Class.java:1808)
    	at sun.reflect.annotation.AnnotationType$1.run(AnnotationType.java:104)
    	at sun.reflect.annotation.AnnotationType$1.run(AnnotationType.java:101)
    	at java.security.AccessController.doPrivileged(Native Method)
    	at sun.reflect.annotation.AnnotationType.<init>(AnnotationType.java:100)
    	at sun.reflect.annotation.AnnotationType.getInstance(AnnotationType.java:84)
    	at sun.reflect.annotation.AnnotationParser.parseAnnotation(AnnotationParser.java:221)
    	at sun.reflect.annotation.AnnotationParser.parseAnnotations2(AnnotationParser.java:88)
    	at sun.reflect.annotation.AnnotationParser.parseAnnotations(AnnotationParser.java:70)
    	at java.lang.reflect.Field.declaredAnnotations(Field.java:1033)
    	at java.lang.reflect.Field.getDeclaredAnnotations(Field.java:1026)
    	at java.lang.reflect.AccessibleObject.getAnnotations(AccessibleObject.java:196)
    	at org.junit.runners.model.FrameworkField.getAnnotations(FrameworkField.java:26)
    	at org.junit.runners.model.TestClass.addToAnnotationLists(TestClass.java:52)
    	at org.junit.runners.model.TestClass.<init>(TestClass.java:45)
    	at org.junit.runners.ParentRunner.<init>(ParentRunner.java:73)
    	at org.junit.runners.BlockJUnit4ClassRunner.<init>(BlockJUnit4ClassRunner.java:55)
    	at org.junit.internal.builders.JUnit4Builder.runnerForClass(JUnit4Builder.java:13)
    	at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
    	at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:29)
    	at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57)
    	at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:24)
    	at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:51)
    	at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:123)
    	at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:104)
    	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    	at java.lang.reflect.Method.invoke(Method.java:601)
    	at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:164)
    	at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:110)
    	at org.apache.maven.surefire.booter.SurefireStarter.invokeProvider(SurefireStarter.java:175)
    	at org.apache.maven.surefire.booter.SurefireStarter.runSuitesInProcessWhenForked(SurefireStarter.java:107)
    	at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:68)


My persistence.xml file is:

    <?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="PU" transaction-type="JTA">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
        <jta-data-source>jdbc/modelsystemdb</jta-data-source>
        <exclude-unlisted-classes>false</exclude-unlisted-classes>
        <properties/>
      </persistence-unit>
    </persistence>

What should I do to make the test run?



