[m2e-dev] m2e connector produces "Internal error updating Maven Project"

["Thorsten Heit" <thorsten.heit@xxxxxx>]

Hi,

sorry for the long post, but I hope
someone can enlighten me why a self-written m2e connector doesn't work...:


I'm creating Java code from a WSDL
via the JAX-WS Maven plugin ([1]) by following some hints I found in a
blog entry ([2]). This works fine using the command line. Here's the relevant
part of my pom.xml:

<plugin>
  <groupId>org.jvnet.jax-ws-commons</groupId>
  <artifactId>jaxws-maven-plugin</artifactId>
  <version>2.2.1</version>
  <executions>
    <execution>
      <goals>
        <goal>wsimport</goal>
      </goals>
    </execution>
  </executions>

  <!-- if you want to use a
specific version of JAX-WS, you can do so like this -->
  <dependencies>
    <dependency>
      <groupId>com.sun.xml.ws</groupId>
      <artifactId>jaxws-tools</artifactId>
      <version>2.1.7</version>
      <exclusions>
        <exclusion>
         
<groupId>org.jvnet.staxex</groupId>
         
<artifactId>stax-ex</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
    <dependency>
      <groupId>org.jvnet.staxex</groupId>
      <artifactId>stax-ex</artifactId>
      <version>1.2</version>
      <exclusions>
        <exclusion>
         
<groupId>javax.xml.stream</groupId>
         
<artifactId>stax-api</artifactId>
        </exclusion>
      </exclusions>
    </dependency>
  </dependencies>
</plugin>

No big magic.


Now I've tried to write a connector
for m2e to a) avoid the tedious "plugin execution not covered by lifecycle
configuration" message and b) have it automatically add the folder
containing the generated sources to the project class path. I've followed
the instructions in the m2e wiki, looked at the code of the antlr connector,
and because I already wrote a connector for the axistools plugin (that
basically does similar things), I thought this would be straightforward.
Unfortunately this doesn't work and results in the following error:



!ENTRY org.eclipse.core.jobs 4 2 2013-05-16
16:58:17.881
!MESSAGE An internal error occurred
during: "Updating Maven Project".
!STACK 0
java.lang.NullPointerException
        at
org.eclipse.m2e.jdt.AbstractJavaProjectConfigurator.getFullPath(AbstractJavaProjectConfigurator.java:65)
        at
org.eclipse.m2e.jdt.AbstractJavaProjectConfigurator.configureRawClasspath(AbstractJavaProjectConfigurator.java:54)
        at
org.eclipse.m2e.jdt.internal.AbstractJavaProjectConfigurator.invokeJavaProjectConfigurators(AbstractJavaProjectConfigurator.java:171)
        at
org.eclipse.m2e.jdt.internal.AbstractJavaProjectConfigurator.configure(AbstractJavaProjectConfigurator.java:127)
        at
org.eclipse.m2e.core.project.configurator.AbstractLifecycleMapping.configure(AbstractLifecycleMapping.java:109)
        at
org.eclipse.m2e.core.internal.project.ProjectConfigurationManager$3.call(ProjectConfigurationManager.java:472)
        at
org.eclipse.m2e.core.internal.project.ProjectConfigurationManager$3.call(ProjectConfigurationManager.java:1)
        at
org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:161)
        at
org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:137)
        at
org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration(ProjectConfigurationManager.java:465)
        at
org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration0(ProjectConfigurationManager.java:403)
        at
org.eclipse.m2e.core.internal.project.ProjectConfigurationManager$2.call(ProjectConfigurationManager.java:316)
        at
org.eclipse.m2e.core.internal.project.ProjectConfigurationManager$2.call(ProjectConfigurationManager.java:1)
        at
org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.executeBare(MavenExecutionContext.java:161)
        at
org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:137)
        at
org.eclipse.m2e.core.internal.embedder.MavenExecutionContext.execute(MavenExecutionContext.java:89)
        at
org.eclipse.m2e.core.internal.embedder.MavenImpl.execute(MavenImpl.java:1301)
        at
org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration(ProjectConfigurationManager.java:313)
        at
org.eclipse.m2e.core.ui.internal.UpdateMavenProjectJob.runInWorkspace(UpdateMavenProjectJob.java:77)
        at
org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:38)
        at
org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)


That's all that I see, nothing more.
I found a message in the mailing list concerning debugging plugin execution
errors ([3]); therefore installed the "m2e - slf4j over logback logging"
plugin, changed the log level in the logback configuration file in .metadata/.plugins/org.eclipse.m2e.logback.configuration
to "DEBUG", but all that didn't change anything. IIUC there
should be a log file in ${org.eclipse.m2e.log.dir}/0.log, but this file
doesn't exist / isn't generated. Starting Eclipse from the command line
outputs the following additional messages when it comes up:

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP)
logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder
for further details.
org.eclipse.m2e.logback.configuration:
SLF4J logger factory is not an instance of LoggerContext: org.slf4j.helpers.NOPLoggerFactory



Questions:
- What does the above message in my
terminal means? It isn't shown anywhere else, btw.
- What can I do to turn on (debug)
logging?
- How can I find out why the connector
doesn't work?

The connector code itself is quite
similar to my axistools connector, so I can only imagine that there's something
different inside the plugin that lets the error occur when being executed
within m2e and my connector. As far as I can tell the plugin itself spawns
a process for the $JAVA_HOME/bin/wsimport executable which in turn generates
the Java sources.

BTW, the connector code is available
at my Github site ([4]).


My configuration:
* Eclipse 4.3M7 (fresh installation)
* m2e 1.4 RC1
* JDK 1.7.0u21



Regards

Thorsten


[1] http://jax-ws-commons.java.net/jaxws-maven-plugin
[2] https://blogs.oracle.com/enterprisetechtips/entry/using_jax_ws_with_maven
[3] http://dev.eclipse.org/mhonarc/lists/m2e-users/msg02408.html
[4] https://github.com/theit/m2e-jaxws