Force neo4j-ce.exe (2.3.0) to use Java 8? - neo4j

Question

I'm running Neo4j 2.3.0 on Win 7 x64.
The computer is configured to use Java 8:
>java -version
java version "1.8.0_66"
Java(TM) SE Runtime Environment (build 1.8.0_66-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.66-b17, mixed mode)
and yet, my extension throws Unsupported major.minor version 52.0:
java.lang.UnsupportedClassVersionError: org/apache/tinkerpop/gremlin/structure/io/graphson/GraphSONMapper :
Unsupported major.minor version 52.0
EDIT Neo4j is finding/using some other version of Java:
16:24:56.199 [qtp1471980130-55] ERROR c.t.neo4j.plugins.GremlinPlugin - java.vendor=Oracle Corporation
16:24:56.209 [qtp1471980130-55] ERROR c.t.neo4j.plugins.GremlinPlugin - java.version=1.7.0
I have JAVA_HOME and my path variables set correctly for generic Java usage (not sure whether Neo4j can use some other env variables?)
Here's the log:
Error saving DB location
java.io.FileNotFoundException: .dblocation (Access is denied)
2015-10-25 12:47:57.115+1100 INFO [o.n.s.d.LifecycleManagingDatabase] Successfully started database
2015-10-25 12:47:57.355+1100 INFO [o.n.s.CommunityNeoServer] Starting HTTP on port 7474 (8 threads available)
2015-10-25 12:47:58.145+1100 INFO [o.n.s.m.ThirdPartyJAXRSModule] Mounted unmanaged extension [com.thinkaurelius.neo4j.plugins] at [/tp]
2015-10-25 12:47:58.365+1100 INFO [o.n.s.w.Jetty9WebServer] Mounting static content at /webadmin
2015-10-25 12:47:58.545+1100 INFO [o.n.s.w.Jetty9WebServer] Mounting static content at /browser
Oct 25, 2015 12:47:59 PM com.sun.jersey.api.core.PackagesResourceConfig init
INFO: Scanning for root resource and provider classes in the packages:
com.thinkaurelius.neo4j.plugins
Oct 25, 2015 12:47:59 PM com.sun.jersey.api.core.ScanningResourceConfig logClasses
INFO: Root resource classes found:
class com.thinkaurelius.neo4j.plugins.GremlinPlugin
Oct 25, 2015 12:47:59 PM com.sun.jersey.api.core.ScanningResourceConfig init
INFO: No provider classes found.
Oct 25, 2015 12:47:59 PM com.sun.jersey.server.impl.application.WebApplicationImpl _initiate
INFO: Initiating Jersey application, version 'Jersey: 1.19 02/11/2015 03:25 AM'
Oct 25, 2015 12:48:00 PM com.sun.jersey.server.impl.application.WebApplicationImpl _initiate
INFO: Initiating Jersey application, version 'Jersey: 1.19 02/11/2015 03:25 AM'
Oct 25, 2015 12:48:00 PM com.sun.jersey.server.impl.application.WebApplicationImpl _initiate
INFO: Initiating Jersey application, version 'Jersey: 1.19 02/11/2015 03:25 AM'
Oct 25, 2015 12:48:00 PM com.sun.jersey.server.impl.application.WebApplicationImpl _initiate
INFO: Initiating Jersey application, version 'Jersey: 1.19 02/11/2015 03:25 AM'
2015-10-25 12:48:01.095+1100 INFO [o.n.s.CommunityNeoServer] Remote interface ready and available at http://localhost:7474/
Oct 25, 2015 12:48:19 PM com.sun.jersey.spi.container.ContainerResponse mapMappableContainerException
SEVERE: The exception contained within MappableContainerException could not be mapped to a response, re-throwing to the HTTP container
java.lang.UnsupportedClassVersionError: org/apache/tinkerpop/gremlin/structure/io/graphson/GraphSONMapper : Unsupported major.minor version 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at com.thinkaurelius.neo4j.plugins.GremlinPlugin.execute(GremlinPlugin.java:116)
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 com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:205)
at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
at org.neo4j.server.rest.transactional.TransactionalRequestDispatcher.dispatch(TransactionalRequestDispatcher.java:139)
at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:302)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1542)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1473)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1419)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1409)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:409)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:558)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:733)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:800)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1669)
at org.neo4j.server.rest.web.CollectUserAgentFilter.doFilter(CollectUserAgentFilter.java:69)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1125)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1059)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
at org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:52)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
at org.eclipse.jetty.server.Server.handle(Server.java:497)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:310)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:248)
at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:540)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:620)
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:540)
at java.lang.Thread.run(Unknown Source)

Answer 1

The exe artifact for Neo4j community edition comes with it's own JDK - don't remember which version is shipped.
The most easy way to fix this is uninstall the Neo4j and download the zip variant. This way will use your system's JVM.