[ http://issues.apache.org/jira/browse/VELTOOLS-59?page=all ]
Nathan Bubna updated VELTOOLS-59:
---------------------------------
Fix Version: 1.3
2.0
Version: 1.1
1.3
2.0
Assign To: Nathan Bubna
I'll take a look at FileResourceLoader to confirm/fix it there too.
> WebappLoader's isSourceModified() and getLastModified() sometimes fail
> ----------------------------------------------------------------------
>
> Key: VELTOOLS-59
> URL: http://issues.apache.org/jira/browse/VELTOOLS-59
> Project: VelocityTools
> Type: Bug
> Components: VelocityView
> Versions: 1.1, 1.2, 1.3, 2.0
> Environment: WebSphere v5.1.x on Linux and Win32, possibly other appservers
> or versions of WebSphere as well.
> Reporter: Stu Belden
> Assignee: Nathan Bubna
> Priority: Minor
> Fix For: 1.3, 2.0
>
> The org.apache.velocity.tools.view.servlet.WebappLoader class ensures that
> all the paths it can load from end with the '/' character. When loading a
> template from disk in getResourceStream(), WebappLoader ensures that the file
> to be loaded does not start with a '/' character, so the file always loads
> properly.
> However, in isSourceModified(Resource resource) and getLastModified(Resource
> resource), the same sanity check is _not_ made on the path of the resource,
> so you can have a path like /myApp//some/file.vm. The result of this, in my
> environment(s) at least, is that the isSourceModified() check always returns
> true because the file cannot be found. With caching turned on, this leaves
> you with with the Least Efficient Cache Ever, since it always re-reads any
> template requested after the modificationCheckInterval.
> I haven't looked at it carefully, but I think FileResourceLoader may have the
> same behavior.
> An interesting side effect of this unruly behavior is, I think, a
> race-condition bug in the Template class. In the process() method, the first
> thing it does is set its "data" member, the AST of the template, to null.
> However, another thread can get that same data member while it's
> uninitialized. This leads to the "java.lang.Exception: Template.merge()
> failure. The document is null, most likely due to parsing error." error. A
> google search for "Template.merge() failure" turns up a couple web
> applications that, I think, are falling prey to this problem as well. This
> problem is easy to duplicate:
> 1. Enable resource loader caching
> 2. Set the modificationCheckInterval to something small, like 10 seconds.
> 3. Hammer your application with requests.
> I'm not intimately familiar with the internals of velocity, so I'm not sure
> what the fix should be, or even where it should go. FWIW, I ended up writing
> my own ResourceLoader that expects a leading '/' on all template names.
> Thoughts?
--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see:
http://www.atlassian.com/software/jira
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
