Creating EntityManagerFactory in Spring

To create JPA based EntityManagerFactory backed by Hibernate implementation in Spring which gets auto configured, follow the code

@Configuration

@EnableAutoConfiguration

//package containing the mapped model

@EnableJpaRepositories(basePackages = "com.lalit.example.Model")

@EnableTransactionManagement

public class DatabaseConfiguration {

        //You can autowire env which contains values from properties file or you

        //can inject properties directly using $

@Autowired

Environment env;

        //This will also create a pool of connections

@Bean

public DataSource dataSource() {

BasicDataSource dataSource = new BasicDataSource();

dataSource.setDriverClassName(env.getProperty("db.driver"));

dataSource.setUrl(env.getProperty("db.url"));

dataSource.setUsername(env.getProperty("db.username"));

dataSource.setPassword(env.getProperty("db.password"));

dataSource.setPoolPreparedStatements(true);

dataSource.setMaxOpenPreparedStatements(20);

return dataSource;

}

@Bean(name="entityManagerFactory")

public LocalContainerEntityManagerFactoryBean entityManagerFactory() {

// Put all the Hibernate properties

Properties additionalProperties = new Properties();

additionalProperties.put("hibernate.dialect", env.getProperty("hibernate.dialect"));

additionalProperties.put("hibernate.show_sql", env.getProperty("hibernate.show_sql"));

additionalProperties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));

LocalContainerEntityManagerFactoryBean entityManagerFactory = new LocalContainerEntityManagerFactoryBean();

entityManagerFactory.setDataSource(dataSource());

JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter(); entityManagerFactory.setJpaVendorAdapter(vendorAdapter);

entityManagerFactory.setJpaProperties(additionalProperties);

entityManagerFactory.setJpaProperties(additionalProperties);

return entityManagerFactory;

}

        //Hook the transaction manager

@Bean

public PlatformTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {

JpaTransactionManager transactionManager = new JpaTransactionManager();

transactionManager.setEntityManagerFactory(entityManagerFactory);

return transactionManager;

}

        //Hook the exception translator

@Bean

public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {

return new PersistenceExceptionTranslationPostProcessor();

}

}