How is it possible to configure EntityManager in Hibernate without using persistence.xml? Maybe there is an approach to creating a configuration through annotations or directly in the code? I will be glad to any link

  • and how are you going to completely do without configs, even for a spring boot, configs are needed - Sanaev
  • The same SessionFactory can be used without configs by simply configuring everything in the code. My project is being launched by another project because of what hibernate cannot find configs. - Dinar Zaripov
  • But access to the database, the driver to the database as far as I know, is filled only in the config file - Sanaev

1 answer 1

public class HibernateUtil { private static EntityManagerFactory entityManagerFactory; private static EntityManager entityManager; public static EntityManagerFactory getEntityManagerFactory() { return entityManagerFactory; } public static EntityManager getEntityManager() { return entityManager; } public static void shutdown() { if(entityManager != null) { entityManager.close(); } if(entityManagerFactory != null) { entityManagerFactory.close(); } } public static void build(){ entityManagerFactory = new HibernatePersistenceProvider().createContainerEntityManagerFactory( archiverPersistenceUnitInfo(), new HashMap<String, Object>() {{ put(JPA_JDBC_DRIVER, JPA_JDBC_DRIVER); put(JPA_JDBC_URL, JPA_JDBC_URL); put(DIALECT, PostgreSQL95Dialect.class); put(SHOW_SQL, true); 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); }} ); entityManager = entityManagerFactory.createEntityManager(); } private static PersistenceUnitInfo archiverPersistenceUnitInfo() { return new PersistenceUnitInfo() { @Override public String getPersistenceUnitName() { return "YourPersistenceUnit"; } @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 entityClassNames(); } @Override public boolean excludeUnlistedClasses() { return false; } @Override public SharedCacheMode getSharedCacheMode() { return null; } @Override public ValidationMode getValidationMode() { return null; } @Override public Properties getProperties() { return hibernateProperties(); } @Override public String getPersistenceXMLSchemaVersion() { return null; } @Override public ClassLoader getClassLoader() { return null; } @Override public void addTransformer(ClassTransformer transformer) { } @Override public ClassLoader getNewTempClassLoader() { return null; } }; } private static Properties hibernateProperties(){ final Properties properties = new Properties(); properties.put("hibernate.hbm2ddl.auto", "update" ); properties.put("hibernate.show_sql", true); properties.put("hibernate.connection.driver_class", "org.postgresql.Driver" ); properties.put("hibernate.dialect", "org.hibernate.dialect.PostgreSQL95Dialect" ); properties.put("hibernate.connection.datasource", dataSource()); return properties; } private static DataSource dataSource() { final PGSimpleDataSource dataSource = new PGSimpleDataSource(); dataSource.setDatabaseName("dbName"); dataSource.setUser("user"); dataSource.setPassword("password"); return dataSource; } private static List<String> entityClassNames() { Class<?>[] entities = new Class<?>[] { YourEntity.class }; return Arrays.stream(entities).map(Class::getName).collect(Collectors.toList()); }

}