new object throws java.lang.NullPointerException

[Marcus Schopen]

Hi,

I get the following error when opening a users news object:

------------------------------------------
java.lang.NullPointerException
at jease.cms.domain.Factory.sync(Factory.java:73)
at jease.cms.domain.Factory.getProperties(Factory.java:62)
at
jease.cms.web.content.editor.ContentEditor.doLoad(ContentEditor.java:147)
at jfix.zk.ObjectEditor.invokeLoad(ObjectEditor.java:116)
at jfix.zk.ObjectEditor.refresh(ObjectEditor.java:98)
at
jease.cms.web.content.editor.ContentEditor.refresh(ContentEditor.java:102)
at jease.cms.web.content.editor.ContentEditor
$6.actionPerformed(ContentEditor.java:254)
at jfix.zk.Modal$3.onEvent(Modal.java:87)
at org.zkoss.zul.impl.MessageboxDlg
$Button.onClick(MessageboxDlg.java:172)
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:616)
at org.zkoss.zk.ui.impl.EventProcessor.process0(EventProcessor.java:205)
at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:138)
at
org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1636)
at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1420)
at org.zkoss.zk.ui.impl.UiEngineImpl.execUpdate(UiEngineImpl.java:1133)
at
org.zkoss.zk.au.http.DHtmlUpdateServlet.process(DHtmlUpdateServlet.java:567)
at
org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:462)
at
org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:470)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at
jease.cms.web.servlet.JeaseController.doFilter(JeaseController.java:204)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:185)
at
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:151)
at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:929)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:405)
at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:269)
at org.apache.coyote.AbstractProtocol
$AbstractConnectionHandler.process(AbstractProtocol.java:515)
at org.apache.tomcat.util.net.JIoEndpoint
$SocketProcessor.run(JIoEndpoint.java:302)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor
$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:636)
------------------------------------------

I find the following error in the log at the time when the object was
changed:

------------------------------------------
12.09.2011 11:59:21 org.apache.catalina.core.ApplicationDispatcher
invoke
SCHWERWIEGEND: Servlet.service() for servlet jsp threw exception
java.net.SocketException: Connection reset
at
java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:113)
at
java.net.SocketOutputStream.write(SocketOutputStream.java:153)
at
org.apache.coyote.http11.InternalOutputBuffer.realWriteBytes(InternalOutputBuffer.java:218)
at
org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:437)
at
org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:351)
at org.apache.coyote.http11.InternalOutputBuffer
$OutputStreamOutputBuffer.doWrite(InternalOutputBuffer.java:243)
at
org.apache.coyote.http11.filters.ChunkedOutputFilter.doWrite(ChunkedOutputFilter.java:119)
at
org.apache.coyote.http11.AbstractOutputBuffer.doWrite(AbstractOutputBuffer.java:190)
at org.apache.coyote.Response.doWrite(Response.java:533)
at
org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:364)
at
org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:437)
at
org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:351)
at
org.apache.catalina.connector.OutputBuffer.writeBytes(OutputBuffer.java:392)
at
org.apache.catalina.connector.OutputBuffer.write(OutputBuffer.java:381)
at
org.apache.catalina.connector.CoyoteOutputStream.write(CoyoteOutputStream.java:93)
at org.apache.commons.io.IOUtils.copyLarge(IOUtils.java:1026)
at org.apache.commons.io.IOUtils.copy(IOUtils.java:999)
at jfix.servlet.Servlets.write(Servlets.java:47)
at
org.apache.jsp.site.domain.File_jsp._jspService(File_jsp.java:66)
at
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at jease.site.Controller.doFilter(Controller.java:134)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
at
org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:471)
at
org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:402)
at
org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:329)
at
org.apache.jasper.runtime.PageContextImpl.doForward(PageContextImpl.java:745)
at
org.apache.jasper.runtime.PageContextImpl.forward(PageContextImpl.java:716)
at
org.apache.jsp.site.Dispatcher_jsp._jspService(Dispatcher_jsp.java:108)
at
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
at
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:304)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at jease.site.Controller.doFilter(Controller.java:134)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at
org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:684)
at
org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:471)
at
org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:402)
at
org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:329)
at jease.site.Controller.doFilter(Controller.java:149)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
at
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at
org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:563)
at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:399)
at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:317)
at org.apache.coyote.http11.Http11Protocol
$Http11ConnectionHandler.process(Http11Protocol.java:204)
at org.apache.tomcat.util.net.JIoEndpoint
$SocketProcessor.run(JIoEndpoint.java:311)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor
$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:636)
------------------------------------------

I moved the news object to trash and created a new one with the same
content, which works fine. Any ideas?

Ciao!

[Maik Jablonski]

Hi,

> I get the following error when opening a users news object:
>
> ------------------------------------------
> java.lang.NullPointerException
> at jease.cms.domain.Factory.sync(Factory.java:73)
> at jease.cms.domain.Factory.getProperties(Factory.java:62)

somehow a null is stored in the property array of the news object. No
idea what might cause this... I've just checked in two changes which
performs additional null checks so such a null property won't create
the NPE... but this is no fix for the actual cause (which may be hard
to reproduce).

Maybe you can setup a copy of your Jease instance and perform some
property related operations (like adding / removing properties
(with/without Factories), starting/stopping the server in between and
so on). If you find a reproducable schema for creating the NPE, I'm
sure I can fix it.... without a little bit of help of you (or others)
I'm a little bit lost here, because I've lots of other work to do.

> I find the following error in the log at the time when the object was
> changed:
>
> ------------------------------------------
> 12.09.2011 11:59:21 org.apache.catalina.core.ApplicationDispatcher
> invoke
> SCHWERWIEGEND: Servlet.service() for servlet jsp threw exception
> java.net.SocketException: Connection reset

This is unrelated... Tomcat throws this error if a browser closes the
connection before the response is fully written. Maybe Tomcat can be
configured to supress this annoying log... if anyone has an idea,
please share it.

Cheers, Maik

[maik.ja...@gmail.com]

Hi Marcus,

> > I get the following error when opening a users news object:
>
> > ------------------------------------------
> > java.lang.NullPointerException
> > at jease.cms.domain.Factory.sync(Factory.java:73)
> > at jease.cms.domain.Factory.getProperties(Factory.java:62)

I think I've found the bug and fixed it. Jease uses a special database-
aware garbage collector for persistent values (e.g. properties) which
is triggered every hour. The garbage collection wasn't protected
properly by a lock (guess I tried to be to smart in the past), so
there was a rare chance of a property being deleted from the database
before the corresponding content object was saved. Additionally the
user won't see a problem until the server was restarted, because the
in-memory graph was fine in the meanwhile.

If you want to avoid this problem before I release Jease 2.5 (could
take some time), you should download the fixed jfix.jar and copy it to
your installation:

http://jease.googlecode.com/svn/trunk/Jease/WEB-INF/lib/jfix.jar

Cheers, Maik

[Marcus Schopen]

Am Samstag, den 01.10.2011, 12:09 -0700 schrieb
maik.ja...@gmail.com:

Thank you for your very great support! I'll install your fix and give
you some feedback.

Ciao
Marcus