title: Null Exception error when executing Cypher query from Java code. (Neo4J)
body: <p>I have been digging into Neo4j 2.0 GA release and learning to work with it in a sample Java application. I am using a standalone Neo4j db and connecting to it via the java rest bindings from the neo4j-rest-graphdb:2.0.0 dependency jar. Below in the code I am working with...</p>
  
  <pre><code>import org.apache.log4j.Logger;
  import org.neo4j.cypher.javacompat.ExecutionEngine;
  import org.neo4j.cypher.javacompat.ExecutionResult;
  import org.neo4j.graphdb.GraphDatabaseService;
  import org.neo4j.graphdb.Transaction;
  import org.neo4j.rest.graphdb.RestGraphDatabase;
  
  public class NeoService {
  
  Logger log = Logger.getLogger(this.getClass());
  GraphDatabaseService gd; 
  ExecutionEngine engine;
  
  public NeoService(){
      gd = new RestGraphDatabase("http://neo4jbox:7474/db/data/");
      engine = new ExecutionEngine(gd);
  }
  
  
  public String createPerson() {
      ExecutionResult result;
  
      try(Transaction tx = gd.beginTx()){
          log.info("Returned person: " + gd.getNodeById(177L).getProperty("username").toString());
          String query = "match (p:Person{username:'someusername'}) return p";
          result = engine.execute(query);
          tx.success();
          log.info(query);
          log.info(result.dumpToString());
          return result.dumpToString();
      }
  }
  }
  </code></pre>
  
  <p>Just to be sure my db was up and running, I added a line to query for a known existing node and I do get a result back. However, when I attempt to execute the query, I get the following error...</p>
  
  <pre><code>2014-01-15 09:51:20.477  INFO 18078 --- [nio-8080-exec-1] com.yookos.neostart.services.DbService   : Returned person: jomski2009
  2014-01-15 09:51:20.752 ERROR 18078 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause
  
  java.lang.NullPointerException: null
  at org.neo4j.cypher.ExecutionEngine.prepare(ExecutionEngine.scala:75)
  at org.neo4j.cypher.ExecutionEngine.profile(ExecutionEngine.scala:43)
  at org.neo4j.cypher.ExecutionEngine.profile(ExecutionEngine.scala:51)
  at org.neo4j.cypher.javacompat.ExecutionEngine.profile(ExecutionEngine.java:94)
  at com.yookos.neostart.services.DbService.createPerson(DbService.java:35)
  at com.yookos.neostart.controller.HomeController.createPerson(HomeController.java:25)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:606)
  at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:214)
  at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
  at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
  at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:748)
  at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:689)
  at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
  at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945)
  at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876)
  at org.sprinork.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:931)
  at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:822)
  at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
  at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:807)
  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.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilter(WebRequestTraceFilter.java:114)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
  at org.springframework.boot.actuate.autoconfigure.EndpointWebMvcAutoConfiguration$1.doFilterInternal(EndpointWebMvcAutoConfiguration.java:126)
  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
  at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108)
  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
  at org.springframework.boot.actuate.autoconfigure.MetricFilterAutoConfiguration$MetricsFilter.doFilter(MetricFilterAutoConfiguration.java:97)
  at org.springframework.boot.actuate.autoconfigure.MetricFilterAutoConfiguration$MetricsFilter.doFilter(MetricFilterAutoConfiguration.java:82)
  at org.apache.catalina.core.ApplicationFiln.internalDoFilter(ApplicationFilterChain.java:243)
  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
  at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
  at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:680)
  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
  at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
  at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
  at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
  at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
  at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1721)
  at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1679)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
  at java.lang.Thread.run(Thread.java:744)
  </code></pre>
  
  <p>As you can see from the first line in the logs, the db does return the user I requested for. Is there anything I am missing out?</p>
  
  <p>EDIT: I can successfully run these queries on the db from the browser console. I also did try this using an embedded database and it ran successfully from the code. Is there some db configuration on the standalone instance that may be causing this?</p>
  
  <p>Thanks for your help.</p>