Java Null Pointer Exception, browsing; Error 500 [Solved]

1

Hi Guys,

since a week or two, I have isses browsing to openhab. Today I set out to upgrade OH2, to see if something changed. It didn’t. I then updated java, but still NE :frowning:

So I guess it has to be something that has happened in my setup. Strange thing, is that it works just fine when accessing the sitemap directly (http://xenon:8080/basicui/app?sitemap=beckasinen).

Whenever I try without the sitemap, I get null pointer exceptions in jetty, such as;

2017-01-28 17:53:20.150 [WARN ] [eclipse.jetty.servlet.ServletHandler] - /basicui/app
java.lang.IllegalArgumentException: Subscription a45edb8c-8876-4e85-8c3e-497ecd990853 does not exist!
        at org.eclipse.smarthome.io.rest.sitemap.SitemapSubscriptionService.setPageId(SitemapSubscriptionService.java:172)[115:org.eclipse.smarthome.io.rest.sitemap:0.9.0.201701192225]
        at org.eclipse.smarthome.ui.basic.internal.servlet.WebAppServlet.service(WebAppServlet.java:147)[188:org.eclipse.smarthome.ui.basic:0.9.0.201701192225]
        at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)[79:org.eclipse.jetty.servlet:9.2.19.v20160908]
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:587)[79:org.eclipse.jetty.servlet:9.2.19.v20160908]
        at org.ops4j.pax.web.service.jetty.internal.HttpServiceServletHandler.doHandle(HttpServiceServletHandler.java:71)[170:org.ops4j.pax.web.pax-web-jetty:4.3.0]
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577)[77:org.eclipse.jetty.security:9.2.19.v20160908]
        at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.ops4j.pax.web.service.jetty.internal.HttpServiceContext.doHandle(HttpServiceContext.java:287)[170:org.ops4j.pax.web.pax-web-jetty:4.3.0]
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)[79:org.eclipse.jetty.servlet:9.2.19.v20160908]
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.ops4j.pax.web.service.jetty.internal.JettyServerHandlerCollection.handle(JettyServerHandlerCollection.java:80)[170:org.ops4j.pax.web.pax-web-jetty:4.3.0]
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.Server.handle(Server.java:499)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)[70:org.eclipse.jetty.io:9.2.19.v20160908]
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)[81:org.eclipse.jetty.util:9.2.19.v20160908]
        at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)[81:org.eclipse.jetty.util:9.2.19.v20160908]
        at java.lang.Thread.run(Thread.java:745)[:1.8.0_112]

and,

2017-01-28 17:54:01.417 [WARN ] [eclipse.jetty.servlet.ServletHandler] - /start/index
java.lang.NullPointerException
        at java.lang.String.replace(String.java:2240)[:1.8.0_112]
        at org.openhab.ui.dashboard.internal.DashboardServlet.serveDashboard(DashboardServlet.java:74)[168:org.openhab.ui.dashboard:2.0.0.201612272212]
        at org.openhab.ui.dashboard.internal.DashboardServlet.doGet(DashboardServlet.java:63)[168:org.openhab.ui.dashboard:2.0.0.201612272212]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)[19:javax.servlet-api:3.1.0]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)[19:javax.servlet-api:3.1.0]
        at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)[79:org.eclipse.jetty.servlet:9.2.19.v20160908]
        at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:587)[79:org.eclipse.jetty.servlet:9.2.19.v20160908]
        at org.ops4j.pax.web.service.jetty.internal.HttpServiceServletHandler.doHandle(HttpServiceServletHandler.java:71)[170:org.ops4j.pax.web.pax-web-jetty:4.3.0]
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577)[77:org.eclipse.jetty.security:9.2.19.v20160908]
        at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.ops4j.pax.web.service.jetty.internal.HttpServiceContext.doHandle(HttpServiceContext.java:287)[170:org.ops4j.pax.web.pax-web-jetty:4.3.0]
        at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)[79:org.eclipse.jetty.servlet:9.2.19.v20160908]
        at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.ops4j.pax.web.service.jetty.internal.JettyServerHandlerCollection.handle(JettyServerHandlerCollection.java:80)[170:org.ops4j.pax.web.pax-web-jetty:4.3.0]
        at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.Server.handle(Server.java:499)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257)[78:org.eclipse.jetty.server:9.2.19.v20160908]
        at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)[70:org.eclipse.jetty.io:9.2.19.v20160908]
        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)[81:org.eclipse.jetty.util:9.2.19.v20160908]
        at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)[81:org.eclipse.jetty.util:9.2.19.v20160908]
        at java.lang.Thread.run(Thread.java:745)[:1.8.0_112]

Any suggestions how to proceed most welcome… :slight_smile:

2

Does your sitemap match the name of you’re sitemap file? The second word in your for must match the name of the file.

3

I’ve seen that first NPE a couple times before. It seems to occur sometimes when I restart OH2 with my browser window open running BasicUI. But, I’ve never been able to find a way to reproduce it consistently.

4

@Rich, if I run the full line with my sitemap, I get no NE. But if I try without any argument (to get to the UI selection base page), I 100% get the NE.

5

OK, so sometimes the solution is easier than I am expecting; I removed cache, tmp files, and a lock file in the userdata folder, and after starting up oh again it works. Some garbage must have found its way into one of those files.

1 Like
6

Can you detail the cache and tmp file locations that you removed?

Thanks
Andrew

7

After quitting oh, I removed everything in userdata/tmp, userdata/cache and a lockfile in userdata/ ( I think it was named “lock” or “lockfile”).

8

Thanks - ive just done the same and now the interface isnt even loading a web page at all!!!

tmp and cache folders have been recreated on reboot

9

Thats strange. What happens if you enter your sitemap in the url directly?

10

page cannot be found - was getting what you had above before removing the temp stuff - might be in for a reinstall methinks

11

Is there any hints in the oh log? Does everything apart from the web interface work?

12

think its broken big time - I cleared log and rebooted and its not populating anything in there. running service stop openhab2 says service not recognised but a manual start.sh says a service already running

13

root@raspberrypi:/usr/share/openhab2# sudo ./start.sh
Launching the openHAB runtime…
karaf: There is a Root instance already running with name main and pid 3131

and PID seems to be random?

14

So, I don’t know how your installation - I run my oh on my gentoo system, starting it manually, entering into karaf directly. But maybe it faster to reinstall, keeping your conf.

15

yeah think so - was on a snapshot ans wanted to go stable anyway so maybe this is a good way of doing it
Thanks for your help

16

OK so after a reinstall and experiencing the same thing - I created a new blank sitemap and got no error.

Long story short I had this in my sitemap:
Switch item=“test_switch”

which should have been
Switch item=test_switch

once I changed it all sitemap items came back
pity its not easier to troubleshoot these syntax errors

17

If you used Eclipse SmartHome Designer (get 0.80 version), you would see the error:

1 Like
18

OK have only cut the sitemaps by hand - perhaps its time to use the designer - thanks for the suggestion