Develop Reference

JAVA Dropwizard configuration for Neo4j ogm

I'm building a project in JAVA with Dropwizard and are looking to start using Neo4j as database. I have been looking on a lot of different options and think that the spring-data-neo4j lib looks like a good solution.
However, since I haven't been working with Spring earlier, I'm having a hard time figuring out how to setup the configuration classes in order to start building repositoris/DAO's.
I have found a tutorial for integrating springs MySQL-driver, but while reading through the documentation for springs neo4j-driver, I noticed that the neo4j-driver doesn't seem to use the DataSourceFactory establishing a connection.
Anyone have any idea on how to proceed?
Thanks in advance!

cassandra with Spring Data

I'm trying to connect to cassandra database using spring data (preferably jpa). I can not find any clera example how to do it, no guide. I found some for MongoDB and Neo4j, but none for cassandra. On mail page of spring there is a mention of coassandra project but none exmaple or guide is provided. Can any one help?

Which version of spring-data-cassandra are you using?
v.1 https://github.com/spring-projects/spring-data-cassandra v.
v.2 https://github.com/SpringData/spring-data-cassandra
For v.1 see http://docs.spring.io/spring-data/cassandra/docs/1.1.0.RC1/reference/html/#cassandra-connectors
I'm using v.2 and also had problems with finding tutorials/examples. But there are test inside the lib itself. See eg. spring-data-cassandra/cassandra/src/test/resources/org/springdata/cassandra/test/integration/config/XmlConfigTest-context.xml - you need to change only few things to make it work with your DB. When cofig is ready you can use CqlOperations to run your queries:
#Autowired
private CqlOperations cassandraTemplate;
cassandraTemplate.buildSaveNewOperation(new Foo("bar")).execute();
And that's basically it :)

I used spring-data-cassandra-1.1.2.RELEASE. Here are 2 links which provide you detailed steps to configure Cassandra with Spring Data: link1 and link2.
I followed the XML configuration way mentioned in link2, but faced one problem. I guess the ticket for this problem is here and is still open. This problem was resolved by just removing the id attribute from <cassandra:template id="cassandraTemplate" />. This code is from the config xml shown in the section 4.3.2 of link2.
Apart from this I did not face any problems and the Spring data Cassandra integration worked fine.
Section 5.1 from this link can also be used.

Using Java Configuration with auditing in Spring Data JPA

Java configuration was introduced in version 1.2.0 of Spring Data, but I can't figure out how the java configuration for <jpa:auditing> should look like. I couldn't find any examples in the docs, neither did I figure it out by looking at the Spring Data JPA Source.
I'm suspecting it's not possible to translate <jpa:auditing> into java configuration, but as I couldn't find a Jira for the possibly missing feature, I'm unsure. Does anyone know if I still have to use XML configuration if I use Spring Data JPA with auditing?

EDIT: This feature is available as of version 1.5 M1 of Spring Data. See the ticket created by Alex Blomskøld for details.
Activating auditing is currently not supported by the JavaConfig means we introduced in 1.2.0. As we're planning to generally overhaul the auditing infrastructure anyway, would you mind filing a ticket against Spring Data JPA to capture that aspect of the story?

How do we migrate/update the database schema in Grails?

We've been working with Grails for a while and my Team Lead raised some questions about the Grails ORM (GORM):
How do we maintain the database schema once we have moved to production?
Can we update the database schema with Grails?
If the schema is updated, will the changes be automatically reflected / does the framework take care of this?
Is there any plugin for Grails that will allow us to update the schema without headaches?

I recently released the official Grails plugin for database migrations - see http://grails.org/plugin/database-migration and the docs at http://grails-plugins.github.com/grails-database-migration/docs/manual/index.html
I'm working with the author of Liquibase on this, so the older liquibase plugin is now deprecated and the new one should be used since it uses the latest version of Liquibase (2.0) and is officially supported by SpringSource. See http://blog.liquibase.org/2011/01/new-standard-liquibase-plugin-grails-database-migration.html for his announcement.
Ask usage questions on the Grails User mailing list (signup from http://grails.org/Mailing+lists) or the new plugin forum at http://grails-plugins.847840.n3.nabble.com/ or email the author directly :)

Remove dbCreate parameter in DataSource.groovy for your production environment - this will stop GORM from auto-updating DB schema.
Sure. Use LiquiBase plugin.
GORM can do it with dbCreate='update', but it's strongly not recommended. For instance, if you rename a field, GORM/LiquiBase can never determine that you have to migrate the data, and not just drop+create.
In one line: grails db-diff to generate LiquiBase's changelog.xml, and grails migrate -Dgrails.env=<whatever environment> to apply it to respective db server.

While the "auto create" functionality is ok to get a project up and running I find liquibase the best way to keep the db up-to-date. There is a grails plugin and I believe work is under way on a DSL too.
So, create a baseline schema (you could use liquibase's generate-changelog) then make all future changes through liquibase and it will manage the updates, rollbacks and even some db interop for you. You can set your DataSource.groovy config to verify and grails will not start up if the schema does not match the domain config:
environments {
development {
dataSource {
dbCreate = "validate"
You may also be interested in the liquibase-runner plugin to run your migrations on application start.

IntelliJ IDEA Hibernate

I'm learning hibernate and I am running into some issues. I'm reading "Harnessing Hibernate" by O'Reilly. They explain everything using ANT, but since I want to avoid writing a huge build.xml file, I'm trying to get it to work with IntelliJ.
I managed to make a mapping according to a DB table in a MySQL database, and wrote the bean for it. It worked, but I can't find any information on how to generate beans and SQL code, or how to reverse engineer with IntelliJ. I found loads of tutorials about Eclipse, using JBOSS Hibernate tools plugin, and the site claims this support for generating code is already in the standard installation of IntelliJ.
Am I forgetting some configuration such as adding libraries? I'm trying to find this out but I'm desperate now. Please don't suggest me to use Eclipse, I need IntelliJ for my current role.

AFAIK, IntelliJ IDEA includes the complete JPA/Hibernate support in its Ultimate Edition:
Generating Persistence Mappings from Database Schema
IntelliJ IDEA allows you to quickly
generate persistence mappings from any
database schema: Generating
Persistance Mappings
(source: jetbrains.com)
Now, the question is, what edition of Intellij IDEA are you using?

If you add the hbm2ddl to your Hibernate config and ask it to create the database schema you'll get it by running a single test or some other code that exercises Hibernate. Once you have it, turn off create.
Let Hibernate do the work.