So far it had all been pure Spring Framework and Neo4j. However, using the Neo4j code in our domain classes polluted them with graph database details. For this application, we wanted to keep the domain classes clean. Spring Data Neo4j promised to do the heavy lifting for us, so we continued investigating it.

Spring Data Neo4j comes with two mapping modes. The more powerful one depends heavily on AspectJ, see Chapter 26, AspectJ details, so we ignored it for the time being. The simple direct POJO-mapping copies the data out of the graph and into our entities. Good enough for a web-application like ours.

The first step was to configure Maven:

<dependency>
  <groupId>org.springframework.data</groupId>
  <artifactId>spring-data-neo4j</artifactId>
  <version>2.0.1.RELEASE</version>
</dependency>

The Spring context configuration was even easier, thanks to a provided namespace:

<beans xmlns="http://www.springframework.org/schema/beans" ...
       xmlns:neo4j="http://www.springframework.org/schema/data/neo4j"
       xsi:schemaLocation="... http://www.springframework.org/schema/data/neo4j
       http://www.springframework.org/schema/data/neo4j/spring-neo4j-2.0.xsd">
    ...
    <neo4j:config storeDirectory="data/graph.db"/>
    ...
</beans>