Ich habe ein einfaches Repository erstellt, das alle Personen in meinem System enthält. Alles scheint gut zu funktionieren. Ich kann einzelne Personen basierend auf einem bestimmten Schlüssel und Wert hinzufügen, entfernen und sogar abrufen, aber aus irgendeinem Grund kann ich nicht alle im Repository gespeicherten Personen direkt abrufen. Ich habe es mit der findAll () -Methode versucht, die eine iterable zurückgeben sollte. Ich versuche dann, mit dem iterable zu iterieren und jede Person in einer Reihenliste zu speichern, die ich die Funktion zurückbringen möchte.

    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;
}

Die Druckzeile gibt "3" aus, damit das Repository nicht leer ist, aber ich erhalte dennoch eine Nullpunkt-Ausnahme im folgenden Fehler.

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)

Ich habe schon Stunden verschwendet, um das zu beheben, aber ohne Glück. Kann mir bitte jemand hier raushelfen?