[Neo4j] [SDN] Example of using Gremlin with Spring-Data repository?

Marc de Verdelhan

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Mar 12, 2012, 1:12:07 PM3/12/12

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Hello,

Does anyone would have a detailed example of using Gremlin (All what I found was using Cypher) with SDN repositories?

I get an exception when I try to call this method:

public interface MyRepository extends GraphRepository<Project> {

@Query(value="{0}", type=QueryType.Gremlin)

String findOtherProjectsOfOwner(Project myProject);

}

The exception:

Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 6.278 sec <<< FAILURE!

testFindOtherProjectsOfOwner(com.mygroup.myapp.data.MyRepositoryTest) Time elapsed: 5.78 sec <<< ERROR!

org.springframework.dao.InvalidDataAccessResourceUsageException: Error executing statement {0}; nested exception is java.lang.NullPointerException

at org.springframework.data.neo4j.support.query.GremlinQueryEngine.query(GremlinQueryEngine.java:50)

at org.springframework.data.neo4j.repository.query.GraphRepositoryQuery.dispatchQuery(GraphRepositoryQuery.java:96)

at org.springframework.data.neo4j.repository.query.GraphRepositoryQuery.execute(GraphRepositoryQuery.java:70)

at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:302)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)

at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)

at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:155)

at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)

at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)

at $Proxy39.findProductCycles(Unknown Source)

at com.mygroup.myapp.data.MyRepositoryTest.testFindOtherProjectsOfOwner(MyRepositoryTest.java:61)

Regards,

MV

Peter Neubauer

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Mar 12, 2012, 1:53:14 PM3/12/12

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Here is a test doing that, is that what you are looking for?
https://github.com/SpringSource/spring-data-neo4j/blob/master/spring-data-neo4j/src/test/java/org/springframework/data/neo4j/repository/PersonRepository.java#L43

Cheers,

/peter neubauer

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Marc de Verdelhan

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Mar 13, 2012, 7:50:44 AM3/13/12

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Thank you for your answer Peter. It's what I was looking for. :)

The exception was occuring because I had forgotten to add gremlin-groovy to my pom.xml

Cheers,

MV

Marc de Verdelhan

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Mar 13, 2012, 8:30:07 AM3/13/12

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Is the Gremlin query engine fully compatible with the original Gremlin?

This statement works fine: @Query(value="g.v(project)", type=QueryType.Gremlin)

... but this one ( @Query(value="g.v(project).as('p')", type=QueryType.Gremlin) ) throws an exception:

java.lang.NoClassDefFoundError: com/tinkerpop/pipes/util/Table

at org.springframework.data.neo4j.support.query.GremlinExecutor.getRepresentation(GremlinExecutor.java:90)

at org.springframework.data.neo4j.support.query.GremlinExecutor.query(GremlinExecutor.java:62)

at org.springframework.data.neo4j.support.query.GremlinQueryEngine.query(GremlinQueryEngine.java:47)