Checkstyle Error - "Got an exception - java.lang.ClassCastException "

Email from Incze Lajos [incze@mail.matav.hu]:

On Fri, Jun 13, 2003 at 04:40:44PM +0800, Willie Vu wrote:
> Vincent,
>
> After I changed antlr plugin to use 2.7.2, I run into this problem:
>
> XXX.java: 0: Got an exception - java.lang.ClassCastException
>
> What is the problem?
>
> Willie
>

I think, I've ran into the same problem - and nothing to do with the new checkstyle jar in my case. You cab check this by looking at the checkstyle reports in target - they are all right at me.

The problem is that in my project.xml I'm using the

<sourceDirectory>$

/$

"/>

And the whole jsl processing is went wrog from this, as the transformer would be working with a $

/<basedir_relative_filename>
from here. Sometimes it causes exception, sometimes simply wrong.

A dirty/quick cure to modify project.xml not to use $

(altough if you use reactor you may get troubles with that). I'm thinking how to patch the jsl script, just wrote this, maybe more knowledgeable jelliers are faster at fix than I am.

incze

OK. My previous diagnosis was all right (I've caught a real bug),
but the main disease was different. And it's not maven. Studying
the "target/checkstyle-raw-report.xml" which is produced by the
ant:checkstyle target and especially the ant:formatter target
inside, you can find lines like this one:

<error line="87" column="5" severity="error" message="Method 'setLanguague' is not designed for extension - needs to be abstract, final or empty." source="com.puppycrawl.tools.checkstyle.checks.DesignForExtensionCheck"/>

And this is the bad news: ' is good for html but bad for
XML. So, the result file is not well formed. And yes, now
I tested that this was the real problem, you can do it, too:

1. Run site:generate
2. Edit target/checkstyle-raw-report.xml and chacge all
"'" to "'".
3. Run xdoc
4. Run site:fsdeploy or site:sshdeploy: and viola: you'll
get a good checkstyle report.

So we have two issues:
1. maven checkstyle plugin's formatting jsl can't handle the
$

/src/java construct in project.xml.
2. ant:checkstyle/ant:formatter produces ill XML.

As someone pointed out the ' problem was a false ring, it
is a predefined XML entity.

Further investigations show, that the real problem is some
sort of influence (not obvious how) of the jdepend plugin report
on the checkstyle plugin report.If the jdepend preceeds the
checkstyle in the order of reports (which is the default if
the POM does not contains explicitly the <reports> tag), then
the checkstyle report fails. As a temporary workaround we
should change the order of these two reports in the default,
and anybody defining it's own <reports> in POM should place
jdepend after checkstyle.

incze

Don't know if this helps narrow it down, but if I run a checkstyle report as part of the "site" or "dist" goals, then I get the same problem - each source file reports a "Class Cast Exception" on line 0, and in the System error output I see the message "Can't find/access AST Node typecom.puppycrawl.tools.checkstyle.api.DetailAST".

However, if I subsequently run a "maven checkstyle" by itself, the checkstyle executes correctly and the checkstyle-raw-report (and xml version of the report) are full of the expected checkstyle errors.

My build source code is under src/java as specified in my project.xml file. (<sourceDirectory>src/java</sourceDirectory>)

I should note that swapping the order of reports (jdepend and checkstyle) (as suggested above by Incze Lajos [ 16/Jun/03 07:19 PM ]) did not have any effect - I get the ClassCastException reported either way.

Just a hunch, but it might be worth a try. The Eclipse checkstyle plugin has a problem with the RedundantThrows check (com.puppycrawl.tools.checkstyle.checks.RedundantThrowsCheck) that causes it to say 'Unable to get class information for ...'. Perhaps the maven plugin is having trouble with the same check. Disabling the check should allow you to find out.

There's discussion of the problem here: http://sourceforge.net/tracker/index.php?func=detail&aid=748678&group_id=80344&atid=559494

Done.

Still having this problem using maven rc-1 and checkstyle plugin 2.2.

The checkstyle report works if running alone (maven checkstyle). It doesn't work using more goals.
This happens on different project, you can try using pom from displaytag
http://cvs.sourceforge.net/viewcvs.py/displaytag/displaytag2/project.xml
or jtidy
http://cvs.sourceforge.net/viewcvs.py/jtidy/jtidy2/project.xml.

Running on Windows JDK 1.4 version "1.4.1_03".

In the log you get the following message for each class "Can't find/access AST Node typecom.puppycrawl.tools.checkstyle.api.DetailAST". And the report is filled with: "Got an exception - java.lang.ClassCastException ".

Tryed removing report or goals: the ceckstyle plugin seem to work only if the checkstyle goal is run alone.