I found 2 possibilities without changing classloader/using other Maven plugins/profiles/copy-overwrite files.
TL;DR: check provider name.
At first I started to construct the entityManagerFactory programmatically, like here: create entity manager programmatically without persistence file.
So I did sth very similar:
@BeforeClass
public static void prepare() {
Map<String, Object> configOverrides = new HashMap<>();
configOverrides.put("hibernate.connection.driver_class", "org.h2.Driver");
configOverrides.put("hibernate.connection.url", "jdbc:h2:mem:test;DB_CLOSE_DELAY=-1");
configOverrides.put("hibernate.connection.username", "sa");
configOverrides.put("hibernate.connection.password", "sa");
configOverrides.put("hibernate.dialect", "org.hibernate.dialect.H2Dialect");
configOverrides.put("hibernate.show_sql", "true");
configOverrides.put("hibernate.hbm2ddl.auto", "validate");
factory = new HibernatePersistence().createContainerEntityManagerFactory(
new CustomPersistenceUnitInfo(), configOverrides
);
//factory = Persistence.createEntityManagerFactory("test");
assertNotNull(factory);
}
...
private static class CustomPersistenceUnitInfo implements PersistenceUnitInfo {
@Override
public String getPersistenceUnitName() {
return "test";
}
@Override
public String getPersistenceProviderClassName() {
return "org.hibernate.jpa.HibernatePersistenceProvider";
// <------------note here: this is wrong!
}
@Override
public PersistenceUnitTransactionType getTransactionType() {
return PersistenceUnitTransactionType.RESOURCE_LOCAL;
}
@Override
public DataSource getJtaDataSource() {
return null;
}
@Override
public DataSource getNonJtaDataSource() {
return null;
}
@Override
public List<String> getMappingFileNames() {
return Collections.emptyList();
}
@Override
public List<URL> getJarFileUrls() {
try {
return Collections.list(this.getClass()
.getClassLoader()
.getResources(""));
} catch (IOException e) {
throw new UncheckedIOException(e);
}
}
@Override
public URL getPersistenceUnitRootUrl() {
return null;
}
@Override
public List<String> getManagedClassNames() {
return Arrays.asList(
"com.app.Entity1",
"com.app.Entity2"
);
}
@Override
public boolean excludeUnlistedClasses() {
return true;
}
@Override
public SharedCacheMode getSharedCacheMode() {
return null;
}
@Override
public ValidationMode getValidationMode() {
return null;
}
@Override
public Properties getProperties() {
return null;
}
@Override
public String getPersistenceXMLSchemaVersion() {
return null;
}
@Override
public ClassLoader getClassLoader() {
return null;
}
@Override
public void addTransformer(final ClassTransformer classTransformer) {
}
@Override
public ClassLoader getNewTempClassLoader() {
return null;
}
}
But then, I found it still return null. Why?
Then I found that when I use com.hibernate.ejb.HibernatePersistence class, the provider should not be com.hibernate.jpa.HibernatePersistenceProvider, but com.hibernate.ejb.HibernatePersistence. The class HibernatePersistenceProvider is not even found with IDEA "Open Class", even when it is in the main persistence.xml.
In Ejb3Configuration.class I found:
integration = integration != null ? Collections.unmodifiableMap(integration) : CollectionHelper.EMPTY_MAP;
String provider = (String)integration.get("javax.persistence.provider");
if (provider == null) {
provider = info.getPersistenceProviderClassName();
}
if (provider != null && !provider.trim().startsWith(IMPLEMENTATION_NAME)) { // private static final String IMPLEMENTATION_NAME = HibernatePersistence.class.getName(); which, is, "com.hibernate.ejb.HibernatePersistence"
LOG.requiredDifferentProvider(provider);
return null;
} else {
So I went back to the first solution of persistence.xml, and change provider name, and now it works. It seems that even the provider in main is jpa.xxx, in tests it is not.
So, in summary, 3 things to check:
- turn on
-X in Maven to check if maven-resources-plugin really copied your src/test/resources/META-INF/persistence.xml into target/test-classes(I think this never fails)
- check if
hibernate-entitymanager is in your classpath(you can check with mvn dependency:tree -Dincludes=org.hibernate:hibernate-entitymanager.
- check provider's name, most important one. Should be
org.hibernate.ejb.HibernatePersistence.
<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="test" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>com.app.model.Company</class>
...
