JPA + Spring how to initialize database with custom tables and data - database

Question

In my application I use Spring context and JPA. I have some set of entities annotated with #Entity and tables for them are created automatically during system startup. Recently I started using Spring ACL, so I have to have the following additional DB schema and I don't want these tables to be mapped to the entities (simply I don't need them to, because Spring ACL manages them independently).
I want to automatically insert e.g. admin user account into the
User's entity table. How to do that properly?
I want to initialize Spring ACL custom tables during system startup, but the SQL script file does not seem to be good solution because if I use different database for production and functional testing, the different SQL dialect does not allow me to execute script properly on both engines (e.g. when using MySQL and HSQL).
At first I tried to use ServletListener that during servlet initialization check the db and adds the necessary data and schema, but this does not work for integration tests (because there are no servlet involved at all).
What I want to achieve is the Spring bean (?) that is launched after the JPA has initialized all entity tables, insert all startup data using injected DAOs and somehow creates the Spring ACL schema. Then - I want the bean to be removed from IoC (because I simly don't need it anymore). Is it possible?
Or is there any better way of doing this?

Answer 1

The default JPA allows you to add an SQL script upon loading the persistence.xml:
http://docs.oracle.com/javaee/7/tutorial/persistence-intro005.htm
Add this property to your persistence.xml file:
<property name="javax.persistence.sql-load-script-source"
value="META-INF/sql/data.sql" />
And fill the data.sql file with your default values.

Answer 2

If you are using EclipseLink you could use a SessionEventListener to execute code after JPA login. You could perform your schema creation and setup in a postLogin event.
You could use the Schema Framework in EclipseLink (org.eclipse.persistence.tools.schemaframework) to create tables and DDL in a database platform independent way. (TableDefinition, SchemaManager classes)

Answer 3

I use PostConstruct annotation to invoke initialize methods.
As document described: The PostConstruct annotation is used on a method that needs to be executed after dependency injection is done to perform any initialization. You may simply add a spring bin with methods has #PostConstruct annotation on it, the methods would be executed after tables are created(or we can say, they are executed after other beans are ready).
Code sample:
#Component
public class EntityLoader {
#Autowired
UserRepository userRepo;
#PostConstruct
public void initApiUserData() {
User u = new User();
// set user properties here
userRepo.save(u);
}
}

Answer 4

If you use hibernate, then create a sql script import.sql in the class path root. Hibernat will execute it on startup. -- This worked in former hibernate version. In the docu of the current version 4.1 I have not found any hint of this feature.
But Hibernate 4.1 has an other feature
Property: hibernate.hbm2ddl.import_files
Comma-separated names of the optional files containing SQL DML statements executed during the SessionFactory creation. This is useful for testing or demoing: by adding INSERT statements for example you can populate your database with a minimal set of data when it is deployed.
File order matters, the statements of a give file are executed before the statements of the following files. These statements are only executed if the schema is created ie if hibernate.hbm2ddl.auto is set to create or create-drop.
e.g. /humans.sql,/dogs.sql

Answer 5

You could try using flyway to
create the tables using the SQL DDL as an SQL migration and
possibly put some data in the tables using either SQL or Java based migrations. You might want to use the latter if in need of environment or other info.
It's a lot easier than it sounds and you will also end up with flyway itself as a bonus, if not a must.