Question

I´m getting a little bit lost in my own (maven enabled) dynamic WEB – Project. The project works fine, I´ve got a RESTful WebService (Jersey) running and I´m able to consume it.

… my next step was to persist my domain classes, with Spring Data and Neo4j. So, I´ve added some tags to my pom.xml

...
<repository>
  <id>spring-milestone</id>
  <name>Spring Maven MILESTONE Repository</name>
  <url>http://maven.springframework.org/milestone</url>
</repository>

<dependency>
  <groupId>org.springframework.data</groupId>
  <artifactId>spring-data-neo4j</artifactId>
  <version>2.0.0.RELEASE</version>
</dependency>
...

my next step was to annotate my entity-classes… here is a simple example:

...
@NodeEntity
public class Category {

@GraphId Long nodeId;
String categoryType;

public Category(String categoryType){
    this.categoryType = categoryType;
}

}
...

okay, everything´s fine… now I want to persist my category-object…

@Autowired Neo4jTemplate template;
@Test @Transactional 
public void toGraphDb() {

      template.save(new Category("mashineCategory"));
}   

when I run the test I´m getting a NullPointerException, cause the template is null

I guess there is something missing in my project, but I´m not sure in which folder/file to add informations/files…

here is my web.xml:

...
<display-name>ElisaSimulatorM4</display-name>

<servlet>
  <servlet-name>Jersey REST Service</servlet-name>
   <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
<init-param>
  <param-name>com.sun.jersey.config.property.packages</param-name>
  <param-value>de.elisa.communication.webservice.restservice.implementation</param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
</servlet>


<servlet-mapping>
  <servlet-name>Jersey REST Service</servlet-name>
  <url-pattern>/rest/*</url-pattern>
</servlet-mapping>
...

in some guides I read something about dispatcherServlets and an applicatonContext.xml, but I have no idea where to put it in my project.

Maybe someone can help me out…

Ps. I wanted to upload a screenshot from my project-tree but as a greenhorn I haven’t got enough reputation… sorry for that

Answer 1

Perhaps it is best to look into the supplied examples of Spring Data Neo4j http://spring.neo4j.org/examples there are some for simple projects like hello-world and some for more advanced web-applications cineasts.

To get the idea the Spring Documentation about the general setup of a Spring(Web) application should help you.

You should probably start with a console application to get the ideas and then incorporate that in your web-application.

The applicationContext.xml file is the SpringFramework configuration file. It should be enough to have a minimal one, like this from the hello-world example.

Put it in src/main/resources/applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:neo4j="http://www.springframework.org/schema/data/neo4j"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/data/neo4j http://www.springframework.org/schema/data/neo4j/spring-neo4j-2.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

    <context:spring-configured/>
    <context:annotation-config/>

    <neo4j:config storeDirectory="path/to/db"/>
    <neo4j:repositories base-package="org.example.repository"/>

</beans>