lawrence mcalpin

So I have this Spring app that uses Hibernate and I’ve defined my model.  And I want to generate the DDL that I need to run to get the database in sync with my model.  I also want to get the DDL for tables needed for use with the Envers auditing framework. Here’s how you get all that:

@Autowired
LocalContainerEntityManagerFactoryBean lcemfb;

public void printUpdateScripts() {
	Ejb3Configuration ejb3 = new Ejb3Configuration();
	ejb3.configure(lcemfb.getPersistenceUnitInfo(),
			lcemfb.getJpaPropertyMap());
	Configuration config = ejb3.getHibernateConfiguration();
	config.buildMappings();
	AuditConfiguration.getFor(config); // include audit tables
	Dialect dialect = Dialect.getDialect(config.getProperties());
	DatabaseMetadata metadata;
	Connection conn = null;
	try {
		EntityManager em = lcemfb.getObject().createEntityManager();
		conn = ((HibernateEntityManager) em).getSession().connection();
		metadata = new DatabaseMetadata(conn, dialect);
		String[] scripts = config.generateSchemaUpdateScript(dialect,
				metadata);
		// String[] scripts = config.generateSchemaCreationScript(dialect);
		// String[] scripts = config.generateDropSchemaScript(dialect);
		for (String script : scripts) {
			System.out.println(script);
		}
	} catch (Throwable t) {
		t.printStackTrace();
	} finally {
		if (conn != null) {
			try {
				conn.close();
			} catch (Throwable t) {
				t.printStackTrace();
			}
		}
	}
}

And LocalContainerEntityManagerFactoryBean is just your standard Spring FactoryBean for creating EntityManagerFactory instances.

<bean id="lcemfb" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
 <property name="persistenceUnitName" value="..." />
 <property name="dataSource" ref="..." />
 <property name="jpaVendorAdapter" ref="..." />
</bean>