Spring Data Neo4J存储库findAll（）导致nullpointerexception

Question

I have made a simple Repository containing all the persons in my system, everything seems to work fine. I can add, remove and even retrieve single persons based on a given key and value but for some reason i can't retrieve all persons stored in the Repository directly. I tried do it by using the findAll() method, which should return an iterable. I then try to iterate with the iterable and store each person in an arraylist which i want the function to return.

    public List<Person> getAllPersons() {
    Iterable<Person> p = personRepository.findAll();
    System.out.println("person count: " + personRepository.count());
    List<Person> persons = new ArrayList<Person>();
    for (Person person : p) {
        System.out.println("person");
        persons.add(person);
    }
    return persons;
}

The printline prints "3" so the repository is not empty but still i get a nullpointerexception in the error below.

apr 16, 2014 3:45:54 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [bmsapp] in context with path [/bmsapp] threw exception [Request processing failed; nested exception is org.neo4j.graphdb.TransactionFailureException: Failed to mark transaction as rollback only.] with root cause
java.lang.NullPointerException
    at org.neo4j.kernel.TopLevelTransaction.markAsRollbackOnly(TopLevelTransaction.java:93)
    at org.neo4j.kernel.TopLevelTransaction.failure(TopLevelTransaction.java:86)
    at org.neo4j.cypher.internal.spi.v2_0.TransactionBoundExecutionContext.close(TransactionBoundExecutionContext.scala:58)
    at org.neo4j.cypher.internal.compiler.v2_0.spi.DelegatingQueryContext.close(DelegatingQueryContext.scala:32)
    at org.neo4j.cypher.internal.compiler.v2_0.spi.ExceptionTranslatingQueryContext.org$neo4j$cypher$internal$compiler$v2_0$spi$ExceptionTranslatingQueryContext$$super$close(ExceptionTranslatingQueryContext.scala:34)
    at org.neo4j.cypher.internal.compiler.v2_0.spi.ExceptionTranslatingQueryContext$$anonfun$close$1.apply$mcV$sp(ExceptionTranslatingQueryContext.scala:34)
    at org.neo4j.cypher.internal.compiler.v2_0.spi.ExceptionTranslatingQueryContext$$anonfun$close$1.apply(ExceptionTranslatingQueryContext.scala:34)
    at org.neo4j.cypher.internal.compiler.v2_0.spi.ExceptionTranslatingQueryContext$$anonfun$close$1.apply(ExceptionTranslatingQueryContext.scala:34)
    at org.neo4j.cypher.internal.compiler.v2_0.spi.ExceptionTranslatingQueryContext.org$neo4j$cypher$internal$compiler$v2_0$spi$ExceptionTranslatingQueryContext$$translateException(ExceptionTranslatingQueryContext.scala:149)
    at org.neo4j.cypher.internal.compiler.v2_0.spi.ExceptionTranslatingQueryContext.close(ExceptionTranslatingQueryContext.scala:34)
    at org.neo4j.cypher.internal.compiler.v2_0.ClosingIterator.failIfThrows(ClosingIterator.scala:94)
    at org.neo4j.cypher.internal.compiler.v2_0.ClosingIterator.next(ClosingIterator.scala:45)
    at org.neo4j.cypher.internal.compiler.v2_0.PipeExecutionResult.next(PipeExecutionResult.scala:168)
    at org.neo4j.cypher.internal.compiler.v2_0.PipeExecutionResult.next(PipeExecutionResult.scala:34)
    at scala.collection.Iterator$$anon$11.next(Iterator.scala:328)
    at scala.collection.convert.Wrappers$IteratorWrapper.next(Wrappers.scala:30)
    at org.neo4j.cypher.internal.compiler.v2_0.PipeExecutionResult$$anon$1.next(PipeExecutionResult.scala:76)
    at org.neo4j.helpers.collection.IteratorWrapper.next(IteratorWrapper.java:47)
    at org.neo4j.helpers.collection.IteratorWrapper.next(IteratorWrapper.java:47)
    at bmsapp.repository.NeoPersonDao.getAllPersons(NeoPersonDao.java:33)
    at bmsapp.service.SimplePersonManager.getPersons(SimplePersonManager.java:32)
    at bmsapp.web.HelloController.HelloHandler(HelloController.java:45)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:175)
    at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:446)
    at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:434)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:744)

I already wasted hours in order to fix this but without any luck. Can anybody please help me out here?

Answer 1

Try mark your personRepository.findAll() as @Transactional .

If it still doesn't work, can you post your personRepository.findAll() method plz?

Answer 2

Thanks for the answers! I have managed to solve the problem by adding

"<tx:annotation-driven mode="proxy"/>

to my application context xml file. It's working perfectly now! However i'm still not sure what this statemant does and why i only need it for the findAll() method and not any of the other's i've used. (count(), findOne(), findBySchemaPropertyValue() etc)

Answer 3

I tried the mode="proxy" and it didn't work for me, this should only have an impact if you are using non-injected transactional methods to call each other (explanation here ).

This 'TransactionFailureException' is probably related to the issue: https://jira.spring.io/browse/DATAGRAPH-531 . If that's the case, you need to change

service.findAll()

to:

service.findAll().as(Collection.class)

... and the it should go away.