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Posted to users@tapestry.apache.org by Andreas Pardeike <an...@pardeike.net> on 2006/06/19 09:41:26 UTC
null exception on invoke, tapestry 3.0.3 - HELP!!
Hi,
I can't get this solved. I had added some extra debugging output and
I waited for 48 hours and contacted the server again. As soon as my
dynamic text component tries to ask the page's visit class for a
specific
text (the database handling is not done inside the text component, I
get the following error:
Component exception : null
------------------------------------------------------------------------
--------
sun.reflect.GeneratedMethodAccessor138.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke
(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:585)
se.pardeike.tapestry.Extras.DBTextSnippet.DBTextSnippet.renderComponent(
DBTextSnippet.java:44)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractComponent.renderBody
(AbstractComponent.java:624)
org.apache.tapestry.components.Conditional.renderComponent
(Conditional.java:56)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.BaseComponent.renderComponent(BaseComponent.java:
118)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractComponent.renderBody
(AbstractComponent.java:624)
org.apache.tapestry.components.RenderBody.renderComponent
(RenderBody.java:45)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractComponent.renderBody
(AbstractComponent.java:624)
org.apache.tapestry.components.Conditional.renderComponent
(Conditional.java:56)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractComponent.renderBody
(AbstractComponent.java:624)
org.apache.tapestry.html.Body.renderComponent(Body.java:269)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractComponent.renderBody
(AbstractComponent.java:624)
org.apache.tapestry.html.Shell.renderComponent(Shell.java:124)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.BaseComponent.renderComponent(BaseComponent.java:
118)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.BaseComponent.renderComponent(BaseComponent.java:
118)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractPage.renderPage(AbstractPage.java:300)
org.apache.tapestry.engine.RequestCycle.renderPage(RequestCycle.java:
368)
org.apache.tapestry.engine.AbstractEngine.renderResponse
(AbstractEngine.java:749)
org.apache.tapestry.engine.AbstractEngine.handlePageRedirectException
(AbstractEngine.java:1045)
org.apache.tapestry.engine.AbstractEngine.service(AbstractEngine.java:
899)
org.apache.tapestry.ApplicationServlet.doService
(ApplicationServlet.java:198)
org.apache.tapestry.ApplicationServlet.doGet(ApplicationServlet.java:
159)
javax.servlet.http.HttpServlet.service(HttpServlet.java:596)
javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:427)
org.mortbay.jetty.servlet.WebApplicationHandler.dispatch
(WebApplicationHandler.java:473)
org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:568)
org.mortbay.http.HttpContext.handle(HttpContext.java:1565)
org.mortbay.jetty.servlet.WebApplicationContext.handle
(WebApplicationContext.java:635)
org.mortbay.http.HttpContext.handle(HttpContext.java:1517)
org.mortbay.http.HttpServer.service(HttpServer.java:954)
org.mortbay.http.HttpConnection.service(HttpConnection.java:816)
org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:983)
org.mortbay.http.HttpConnection.handle(HttpConnection.java:833)
org.mortbay.http.SocketListener.handleConnection(SocketListener.java:
244)
org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:357)
org.mortbay.util.ThreadPool$PoolThread.run(ThreadPool.java:534)
### Note:
### DBTextSnippet.java:44 is
### String txt = (String)snippetGetterMethod.invoke(visitObject,
arguments);
I've attached the two files that are involved to this email: the
page's visit
class and the dynamic text component class. The structure is simple:
a page has
a component <span jwcid="@pardeike:DynamicText" snippet="fshome-
menu1"/> which
is in my own component library. There 'DBTextSnippet' tries to call
getSnippetText()
in page.visit with two parameters (the id and the locale). That will
use cayenne
to fetch the text from a database and returns it to DBTextSnippet
which renders it.
Works perfectly until the server gets idle for a long time.
The code contains a few debugging statements which output:
page : Fsys.Pages.FSHome$Enhance_0@f221f6[FSHome]
visitObject : Fsys.Common.Visit@93c4f1
visitClass : class Fsys.Common.Visit
arguments[0] : fshome-menu1
arguments[1] : sv_SE
snippetGetterMethod : public java.lang.String
Fsys.Common.Visit.getSnippetText(java.lang.String,java.util.Locale)
which to me looks like all my stuff isn't null at all. I'm out of
ideas why
invoke fails here...
Regards,
Andreas Pardeike
Re: null exception on invoke, tapestry 3.0.3 - HELP!!
Posted by Andreas Pardeike <an...@pardeike.net>.
The code also has these debugging statements:
writer.print("page: " + page);
writer.print("visitObject: " + visitObject);
writer.print("visitClass: " + visitClass);
writer.print("arguments[0]: " + arguments[0]);
writer.print("arguments[1]: " + arguments[1]);
writer.print("snippetGetterMethod: " + snippetGetterMethod);
writer.printRaw("<hr>");
and the print this:
page : Fsys.Pages.FSHome$Enhance_0@f221f6[FSHome]
visitObject : Fsys.Common.Visit@93c4f1
visitClass : class Fsys.Common.Visit
arguments[0] : fshome-menu1
arguments[1] : sv_SE
snippetGetterMethod : public java.lang.String
Fsys.Common.Visit.getSnippetText(java.lang.String,java.util.Locale)
So this isn't the case.
On 19 jun 2006, at 15.28, Gunna Satria wrote:
> By looking in the error stack trace below, you must see in your
> DBTextSnippet.java code line 44.
> I got your source but i'm not sure it is really line 44 where's
> the error occur(maybe you have breakline somewhere)
> well, my guess is this below code,
>
> if(snippetGetterMethod == null)
> snippetGetterMethod = visitClass.getMethod(snippetGetter,
> parameterTypes);
> /*this is line 44*/String txt = (String)
> snippetGetterMethod.invoke(visitObject, arguments);
>
> this code tells that if snippetGetterMethod value is null it
> should get the value from visitClass.getMethod(snippetGetter,
> parameterTypes);
> i suggest you have to re-check snippetGetterMethod value after
> being set by visitClass.getMethod(snippetGetter, parameterTypes);
> it is already have the value or it is still null.
>
> if(snippetGetterMethod == null)
> snippetGetterMethod = visitClass.getMethod(snippetGetter,
> parameterTypes);
> if(snippetGetterMethod == null) logger.debug("still null there...");
> String txt = (String)snippetGetterMethod.invoke(visitObject,
> arguments);
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Re: null exception on invoke, tapestry 3.0.3 - HELP!!
Posted by Gunna Satria <gu...@yahoo.com>.
Hi Andreas,
By looking in the error stack trace below, you must see in your DBTextSnippet.java code line 44.
I got your source but i'm not sure it is really line 44 where's the error occur(maybe you have breakline somewhere)
well, my guess is this below code,
if(snippetGetterMethod == null)
snippetGetterMethod = visitClass.getMethod(snippetGetter,
parameterTypes);
/*this is line 44*/String txt = (String)snippetGetterMethod.invoke(visitObject, arguments);
this code tells that if snippetGetterMethod value is null it should get the value from visitClass.getMethod(snippetGetter, parameterTypes);
i suggest you have to re-check snippetGetterMethod value after being set by visitClass.getMethod(snippetGetter, parameterTypes);
it is already have the value or it is still null.
if(snippetGetterMethod == null)
snippetGetterMethod = visitClass.getMethod(snippetGetter,
parameterTypes);
if(snippetGetterMethod == null) logger.debug("still null there...");
String txt = (String)snippetGetterMethod.invoke(visitObject,
arguments);
cheers,
Gunna
Andreas Pardeike <an...@pardeike.net> wrote: Hi,
I can't get this solved. I had added some extra debugging output and
I waited for 48 hours and contacted the server again. As soon as my
dynamic text component tries to ask the page's visit class for a
specific
text (the database handling is not done inside the text component, I
get the following error:
Component exception : null
------------------------------------------------------------------------
--------
sun.reflect.GeneratedMethodAccessor138.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke
(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:585)
se.pardeike.tapestry.Extras.DBTextSnippet.DBTextSnippet.renderComponent(
DBTextSnippet.java:44)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractComponent.renderBody
(AbstractComponent.java:624)
org.apache.tapestry.components.Conditional.renderComponent
(Conditional.java:56)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.BaseComponent.renderComponent(BaseComponent.java:
118)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractComponent.renderBody
(AbstractComponent.java:624)
org.apache.tapestry.components.RenderBody.renderComponent
(RenderBody.java:45)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractComponent.renderBody
(AbstractComponent.java:624)
org.apache.tapestry.components.Conditional.renderComponent
(Conditional.java:56)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractComponent.renderBody
(AbstractComponent.java:624)
org.apache.tapestry.html.Body.renderComponent(Body.java:269)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractComponent.renderBody
(AbstractComponent.java:624)
org.apache.tapestry.html.Shell.renderComponent(Shell.java:124)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.BaseComponent.renderComponent(BaseComponent.java:
118)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.BaseComponent.renderComponent(BaseComponent.java:
118)
org.apache.tapestry.AbstractComponent.render(AbstractComponent.java:857)
org.apache.tapestry.AbstractPage.renderPage(AbstractPage.java:300)
org.apache.tapestry.engine.RequestCycle.renderPage(RequestCycle.java:
368)
org.apache.tapestry.engine.AbstractEngine.renderResponse
(AbstractEngine.java:749)
org.apache.tapestry.engine.AbstractEngine.handlePageRedirectException
(AbstractEngine.java:1045)
org.apache.tapestry.engine.AbstractEngine.service(AbstractEngine.java:
899)
org.apache.tapestry.ApplicationServlet.doService
(ApplicationServlet.java:198)
org.apache.tapestry.ApplicationServlet.doGet(ApplicationServlet.java:
159)
javax.servlet.http.HttpServlet.service(HttpServlet.java:596)
javax.servlet.http.HttpServlet.service(HttpServlet.java:689)
org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:427)
org.mortbay.jetty.servlet.WebApplicationHandler.dispatch
(WebApplicationHandler.java:473)
org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:568)
org.mortbay.http.HttpContext.handle(HttpContext.java:1565)
org.mortbay.jetty.servlet.WebApplicationContext.handle
(WebApplicationContext.java:635)
org.mortbay.http.HttpContext.handle(HttpContext.java:1517)
org.mortbay.http.HttpServer.service(HttpServer.java:954)
org.mortbay.http.HttpConnection.service(HttpConnection.java:816)
org.mortbay.http.HttpConnection.handleNext(HttpConnection.java:983)
org.mortbay.http.HttpConnection.handle(HttpConnection.java:833)
org.mortbay.http.SocketListener.handleConnection(SocketListener.java:
244)
org.mortbay.util.ThreadedServer.handle(ThreadedServer.java:357)
org.mortbay.util.ThreadPool$PoolThread.run(ThreadPool.java:534)---------------------------------------------------------------------
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