Here is a pure programmatic way to build an entity manager without spring and without a persistence.xml. Constants are taken from org.hibernate.cfg.AvailableSettings :
entityManagerFactory = new HibernatePersistenceProvider().createContainerEntityManagerFactory(
archiverPersistenceUnitInfo(),
ImmutableMap.<String, Object>builder()
.put(JPA_JDBC_DRIVER, JDBC_DRIVER)
.put(JPA_JDBC_URL, JDBC_URL)
.put(DIALECT, Oracle12cDialect.class)
.put(HBM2DDL_AUTO, CREATE)
.put(SHOW_SQL, false)
.put(QUERY_STARTUP_CHECKING, false)
.put(GENERATE_STATISTICS, false)
.put(USE_REFLECTION_OPTIMIZER, false)
.put(USE_SECOND_LEVEL_CACHE, false)
.put(USE_QUERY_CACHE, false)
.put(USE_STRUCTURED_CACHE, false)
.put(STATEMENT_BATCH_SIZE, 20)
.build());
entityManager = entityManagerFactory.createEntityManager();
And the infamous PersistenceUnitInfo
private static PersistenceUnitInfo archiverPersistenceUnitInfo() {
return new PersistenceUnitInfo() {
@Override
public String getPersistenceUnitName() {
return "ApplicationPersistenceUnit";
}
@Override
public String getPersistenceProviderClassName() {
return "org.hibernate.jpa.HibernatePersistenceProvider";
}
@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 Collections.emptyList();
}
@Override
public boolean excludeUnlistedClasses() {
return false;
}
@Override
public SharedCacheMode getSharedCacheMode() {
return null;
}
@Override
public ValidationMode getValidationMode() {
return null;
}
@Override
public Properties getProperties() {
return new Properties();
}
@Override
public String getPersistenceXMLSchemaVersion() {
return null;
}
@Override
public ClassLoader getClassLoader() {
return null;
}
@Override
public void addTransformer(ClassTransformer transformer) {
}
@Override
public ClassLoader getNewTempClassLoader() {
return null;
}
};
}
Note that Spring offers streamlined way to configure the persistence, while supporting multiple hibernate versions. (Spring 4.2 supports Hibernate up to 5.1, Spring 4.3 supports Hibernate up to 5.2).
