How to write a unit test with neo4j-in-memory-server

Question

I have written a webservice and would now like to write some unit tests for it. I stumbled across Michael Hunger's in memory server.

Due to the sparse documentation, I have a hard time setting up only one unit test. I cloned the project, included it in my workspace and added it as a dependency to my project.

In order to test my web service, I wrote this method to create an in-memory neo4j server:

@BeforeClass
public static void setupInMemoryServer()
{
    CommunityBootstrapper s = new CommunityBootstrapper();
    int status = -1;
    try
    {
        status = s.start();
    }
    catch(Exception e)
    {
        System.out.println("could not start server");
        e.printStackTrace();
        System.out.println(e.getMessage());
        System.out.println(e.getCause());
        System.out.println(e.getLocalizedMessage());
    }
    System.out.println(hostAvailabilityCheck());
    System.out.println("status = "+status);


}
public static boolean hostAvailabilityCheck() { 
        try (Socket s = new Socket("127.0.0.1", 7474)) {
            return true;
        } catch (IOException ex) {
            System.out.println ("Neo server not online");
        }
        return false;
    }

When I run this code, I get the following output:

Mai 29, 2014 10:13:17 PM org.neo4j.server.logging.Logger log SEVERE: Unable to upgrade database Mai 29, 2014 10:13:17 PM org.neo4j.server.logging.Logger log SEVERE: org.neo4j.server.ServerStartupException: Starting Neo4j Server failed: Startup failed due to preflight task [class org.neo4j.server.preflight.PerformUpgradeIfNecessary]: Unable to upgrade database at org.neo4j.server.AbstractNeoServer.start(AbstractNeoServer.java:218) at org.neo4j.server.Bootstrapper.start(Bootstrapper.java:87) at org.neo4j.server.Bootstrapper.start(Bootstrapper.java:74) at com.youtube.rest.status.test.CreateUserTest.setupInMemoryServer(CreateUserTest.java:26) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:24) at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27) at org.junit.runners.ParentRunner.run(ParentRunner.java:309) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197) Caused by: org.neo4j.server.preflight.PreflightFailedException: Startup failed due to preflight task [class org.neo4j.server.preflight.PerformUpgradeIfNecessary]: Unable to upgrade database at org.neo4j.server.AbstractNeoServer.runPreflightTasks(AbstractNeoServer.java:335) at org.neo4j.server.AbstractNeoServer.start(AbstractNeoServer.java:152) ... 19 more

Mai 29, 2014 10:13:17 PM org.neo4j.server.logging.Logger log SEVERE: Failed to start Neo Server on port [7474]

true

status = 1

Mai 29, 2014 10:13:17 PM org.neo4j.server.logging.Logger log WARNING: Failed to cleanly shutdown database. Mai 29, 2014 10:13:17 PM org.neo4j.server.logging.Logger log INFO: Successfully shutdown Neo Server on port [7474], database [unknown location]

I don't know why this happens since the server is built in memory and everything is (should) created temporarily. I neither understand, how database update conflicts can occur nor how to resolve them.

Answer 1

Based on the string "Unable to upgrade database" in your stack trace, it looks like your database needs to be upgraded, but the upgrade cannot be done automatically. You may need to do an "explicit upgrade", as described on this page.