Why do I have a dependency to gwt?

Question

In a seam-gen generated application the following exception is thrown during deployment:

ERROR [LoadMgr3] Not resheduling failed loading task, loadTask=org.jboss.mx.loading.ClassLoadingTask@8c5c9c{classname: org.jboss.seam.remoting.gwt.GWT14Service, requestingThread: Thread[ScannerThread,5,jboss], requestingClassLoader: org.jboss.mx.loading.UnifiedClassLoader3@3e4532{ url=f
ile:/C:/dev/jboss-4.3.0.GA/server/default/deploy/myapp.ear/ ,addedOrder=50}, loadedClass: nullnull, loadOrder: 2147483647, loadException: java.lang.NoClassDefFoundError: com/google/gwt/user/server/rpc/SerializationPolicyProvider, threadTaskCount: 0, state: 1, #CCE: 1}
java.lang.NoClassDefFoundError: com/google/gwt/user/server/rpc/SerializationPolicyProvider
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
...
        at org.jboss.deployment.scanner.URLDeploymentScanner.deploy(URLDeploymentScanner.java:421)
        at org.jboss.deployment.scanner.URLDeploymentScanner.scan(URLDeploymentScanner.java:610)
        at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.doScan(AbstractDeploymentScanner.java:263)
        at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.loop(AbstractDeploymentScanner.java:274)
        at org.jboss.deployment.scanner.AbstractDeploymentScanner$ScannerThread.run(AbstractDeploymentScanner.java:225)

The problem (and workaround) is described here. Since I don't use gwt, my question is why do I have this dependency when I'm not using gwt at all?

Seam version 2.1.2

EDIT: Just for the records: Until another solution is available I added gwt-servlet.jar in the file deployed-jars-ear.list this satisfies the deployment scanner.

score 1 · Answer 1 · answered Jun 09 '10 at 08:13

1

It looks like some part of seam just depends on classes from the gwt-servlet.jar.

Bet you have to take it as it is and hope for a code cleanup on seam's side, because it is surprising that your're required to add 'gwt' libs to your project even if you do not use gwt.

answered Jun 09 '10 at 08:13

Andreas Dolk

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We can still hope for another answer with a solution how to get rid of this dependency ;) – Andreas Dolk Jun 09 '10 at 08:39

score 1 · Accepted Answer · edited May 23 '17 at 12:30

Here you can see Ant Target responsible for copying libraries used by Seam-gen

<target name="copy-lib" depends="copyseam, copyseamdependencies, copyjbossembedded, copy-icefaces-home, copy-icefaces-maven">
    <echo message="Copying Seam and dependencies to the ${project.home}/lib directory..."/>

    <copy todir="${project.home}/lib" overwrite="true">
        <fileset dir="${seam.dir}/lib">
            <exclude name="jsf-facelets.jar" if="icefaces.property"/>
            <exclude name="ajax4jsf*.jar" if="icefaces.property"/>
            <exclude name="richfaces*.jar" if="icefaces.property"/>
            <exclude name="jboss-container.jar"/>
            <exclude name="jboss-seam-wicket.jar"/>
            <exclude name="jboss-seam-resteasy.jar"/>
            <exclude name="test/jboss-deplyers.jar"/>
            <exclude name="test/jboss-embedded-api.jar"/>
            <exclude name="interop/**/*"/>
            <exclude name="gen/**/*"/>
        </fileset>
        <fileset file="${driver.jar}"/>
    </copy>

    <!-- we must use an endorsed jars directory containing JAXB 2.1 for running SeamTest under Java 6 -->
    <copy todir="${project.home}/lib/endorsed" file="${seam.dir}/lib/gen/jaxb-api.jar" overwrite="true"/>

    <echo message="Copying JBoss Embedded configuration to the ${project.home}/bootstrap directory..."/>
    <copy todir="${project.home}/bootstrap" overwrite="true">
        <fileset dir="${seam.dir}/bootstrap"/>
    </copy>

</target>

Notice it is not exclude GWT library. But As far i know, Seam does not depends on GWT library. So you can set up your custom exclude. Here you can see how your Seam app should looks like.

The build.xml file Seam-gen uses is located in

<SEAM_HOME&GT;/seam-gen/build.xml

Thanks, but there is no other jar in the lib dir but gwt-servlet.jar which name indicates that it could be involved in this issue. — stacker, Jun 09 '10 at 16:31
@stacker Have you seen Chris Bauer comment: http://seamframework.org/Community/NoClassDefFoundExceptionOnGoogleSerializationPolicyProvider#comment72922 — Arthur Ronald, Jun 09 '10 at 16:57
@arthur-ronald-f-d-garcia thanks he says it's logged as DEBUG (including the exception) and user shouldn't worry. Now I'm relaxed and if I have time I'm going to find out why this appears as error. — stacker, Jun 09 '10 at 17:14
For the records I excluded gwt-servlet.jar and jboss-seam-remoting.jar — stacker, Oct 08 '10 at 15:20

Camilo Casadiego · Answer 3 · 2012-10-02T13:30:41.210

0

As a matter of fact, checking on my seam project, the awt library is an internal dependecie for some faces modules, you just need to be sure to add gwt-servlet-2.3.0.jar to your

Project-ear.ear\Project.war\WEB-INF\lib

edited Oct 02 '12 at 13:30

answered Sep 19 '12 at 16:55

Camilo Casadiego

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Why do I have a dependency to gwt?

3 Answers3