Spring Data Rest Neo4j: Template must not be null or empty - neo4j

Question

I am creating what I believe to be a fairly simple domain model in Spring.
#NodeEntity
class Dependency {
#GraphId
private Long id
String groupId
String artifactId
String version
#Fetch
#RelatedTo(type = "DEPENDS_ON", direction = OUTGOING)
Set<Dependency> dependencies = new HashSet<Dependency>()
}
note* the above is written in groovy.
I have also created a subsequent Repository (all textbook so far!).
#RepositoryRestResource(collectionResourceRel = "dependency", path = "dependency")
interface DependencyRepository extends PagingAndSortingRepository<Dependency, Long> {
List<Dependency> findByArtifactId(#Param("artifactId") String artifactId)
}
And finally the application class....
#EnableNeo4jRepositories(basePackages = "io.byteshifter.depsgraph")
#SpringBootApplication
class Application extends Neo4jConfiguration {
public Application() {
setBasePackage("io.byteshifter.depsgraph")
}
#Bean(destroyMethod = "shutdown")
GraphDatabaseService graphDatabaseService() {
return new GraphDatabaseFactory().newEmbeddedDatabase("target/dependency.db")
}
public static void main(String[] args) throws Exception {
SpringApplication.run(Application, args)
}
}
Now I would expect when I fire the following payload at http://127.0.0.1:8080/dependency that it would create all the objects and relationships..
{
"groupId": "group1",
"artifactId": "artifact1",
"version": "1.0",
"dependencies" : [
{"groupId": "group2", "artifactId": "artifact2", "version": "2.0"},
{"groupId": "group3", "artifactId": "artifact3", "version": "3.0"}
]
}
Instead, I get..
{
"cause": {
"cause": {
"cause": null,
"message": "Template must not be null or empty!"
},
"message": "Template must not be null or empty! (through reference chain: io.byteshifter.depsgraph.domain.Dependency[\"dependencies\"]->java.util.LinkedHashSet[0])"
},
"message": "Could not read JSON: Template must not be null or empty! (through reference chain: io.byteshifter.depsgraph.domain.Dependency[\"dependencies\"]->java.util.LinkedHashSet[0]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: Template must not be null or empty! (through reference chain: io.byteshifter.depsgraph.domain.Dependency[\"dependencies\"]->java.util.LinkedHashSet[0])"
}
I have no doubt this is a lack of understanding on my behalf. If anyone could help steer me in the right direction that would be very welcomed.

Answer 1

My REST knowledge has failed me. I should have been using a URI to represent other dependencies. See below:
{
"groupId": "group3",
"artifactId": "artifact3",
"version": "1.0",
"dependencies": ["http://127.0.0.1:8080/dependency/0", "http://127.0.0.1:8080/dependency/1", "http://127.0.0.1:8080/dependency/2"]
}