Wsgen task in stand-alone Ant

Question

Have anyone made a wsgen task in a build.xml file for use with an original Ant-distribution?
(not using org.apache.tools.ant.Main located in weblogic.jar)
I get a non-informing build error when running the wsgen-task. (The ejbc-task
completes successfully).
java.lang.NoSuchMethodError
at weblogic.apache.xerces.jaxp.DocumentBuilderImpl.<init>(DocumentBuilderImpl.java:136)
at weblogic.apache.xerces.jaxp.DocumentBuilderFactoryImpl.newDocumen...bla
bla...
(Project.java:510)
at org.apache.tools.ant.Main.runBuild(Main.java:421)
at org.apache.tools.ant.Main.main(Main.java:149)
If anyone could tell me what to do - that would really make my day(!)
Regards,
Henning Storhaug

Answer 1

There is a little bit of situation using taskdef and a classpath from inside
a build.xml. The problem is that ant creates a custom classloader (which
loads classes the same way ant finds files, ie. replacing /->\, :->;, using
the correct basedir, etc. etc.). Ant uses this classloader to load the class
implementing the task.
Mainly this creates two problems:
- This classloader does not 100% implement the correct protocol of a
classloader, especially when it comes to finding resources. (no disrespect
intended, ant is a great tool!)
- Many classes in Weblogic is not really used to being loaded from a
classloader and doesn't behave very well. (for example: using the
system-classloader directly, assuming that they are located at the
java.system.classpath etc. etc)
This makes it almost impossible to use any weblogic-tasks without loading
weblogic-classes from the system-classpath. And that is why the "trick of
the external build.xml" works, because antcall starts the new ant with a
system-classpath including weblogic.jar.
Don't really now what the best solution to this is. I think that BEA has to
be better writing code that behaves nicer to custom classloaders, and I
think the ant team needs to fix their class-loader a little better.
(especially in respect to resources)
In the meantime use the "external build.xml"-trick or use the ant included
with weblogic.
"Chris" <[email protected]> wrote in message
news:[email protected]...
>
We are actually using Ant 1.4 with Weblogic 6.1 and the wsgen tasksuccessfully..
although I haven't tested myself , I was told that there might be problemsif
the wsgen task is run from the same build.xml file (which might be thereason
for your problem as well)... so what I have done is created a second buildxml
file that includes the wsgen task (and some staging tasks) and I call itfrom
my main build.xml (using antcall).
A couple of things to note is that you have to make sure that you put antin front
of the weblogic.jar in the classpath.. Additionally (and you were rightabout
this) you have to use the taskdef to define the wsgen task as ant will notfind
it by itself..
Here is a sample of the wsgen task I use.
<wsgendestpath="${dir.dsn-build}/webservices_staging/${module.name.Report}WS.ear"
>
context="/${module.name.Report}"
host="localhost"
port="8081"
protocol="http"
webapp="${module.name.Report}-web-services.war">
<rpcservices path="${dir.ear_staging}/ReportEntryEJB.jar">
<rpcservice bean="ReportEntry" uri="/${module.name.Report}uri"/>
</rpcservices>
</wsgen>
"Simon Spruzen" <[email protected]> wrote:
I tried this, and defined a taskdef to allow standalone ant to locate
the WLS ant
wsgen task:
<!-- wsgen - build web services -->
<taskdef name="wsgen" classname="weblogic.ant.taskdefs.ejb.WSGen">
<classpath refid="bea.class.path"/>
</taskdef>
bea.class.path was defined to ensure that weblogic.jar came first.
However, I got a curious error when running wsgen target - can't
remember,
and
don't have, the full details - but it involved a message along the lines
of something
"...violating loader constraints...".
So I just gave up and used the version of Ant that ships with WLS 6.1,
and it
works and I am happy and content.
(But you're stuffed if you want to move to ant 1.4)
"Henning Storhaug" <[email protected]> wrote:
To be a bit more specific:
The wsgen ant-task runs when using the ant-distribution within
weblogic.jar,
but
not using the jakarta-ant-1.3 distribution. I've checked the versions,
and they
are the same.
If you need more info, please ask.