SLF4J classes not visible when added as dependencies to maven-jetty-plugin

Oops, I mean the error is "NoClassDefFoundError: org/slf4j/LoggerFactory" since it's slf4j-api that isn't visible.

According to Jetty classloading architecture (see http://docs.codehaus.org/display/JETTY/Classloading),
org.slf4j.* classes by default are included in so called ServerClasses and are hidden from webapp context classloaders.

I think that you have two possibilities:

1. Override default ServerClasses list excluding org.slf4j. from it. After it webapp context classloader will see slf4j classes from parent classloader.

or

2. Add slf4j dependencies not only to maven-plugin-jetty, but as dependency at top maven pom <dependencies> level . After it webapp context classloader will see slf4j classes from its own WEB-INF/lib/ directory.

Sorry for the false alarm, I didn't know Jetty was hiding certain classes.
Your first suggestion works great, I added this to the plugin configuration and now everything's ok:

<configuration>
<webAppConfig>
<contextPath>/test</contextPath>
<serverClasses>
<filter>-org.mortbay.jetty.plus.jaas.</filter>
<filter>org.mortbay.jetty.</filter>
</serverClasses>
</webAppConfig>
</configuration>

Thanks!

Martin's comment was very helpful to me, but I found that further configuration is required if using jcl-over-slf4j because Jetty exposes the standard Commons Logging API to applications.

Revised configuration:

<webAppConfig>
<contextPath>/test</contextPath>
<serverClasses>
<!-- Copied from WebAppContext with SLF4J removed -->
<filter>-org.mortbay.jetty.plus.jaas.</filter>
<filter>org.mortbay.jetty.</filter>
</serverClasses>
<systemClasses>
<!-- Copied from WebAppContext with Commons Logging and Log4j removed -->
<filter>java.</filter>
<filter>javax.servlet</filter>
<filter>javax.xml.</filter>
<filter>org.mortbay.</filter>
<filter>org.xml.</filter>
<filter>org.w3c.</filter>
</systemClasses>
</webAppConfig>

Apologies for bumping an old, closed bug, but I found this bug when Googling for the problem, and expect this information may be useful to others.

In reply to Ken comment, there's a missing dot on javax.servlet

This is the working configuration.

<webAppConfig>
<contextPath>/test</contextPath>
<serverClasses>
<!-- Copied from WebAppContext with SLF4J removed -->
<filter>-org.mortbay.jetty.plus.jaas.</filter>
<filter>org.mortbay.jetty.</filter>
</serverClasses>
<systemClasses>
<!-- Copied from WebAppContext with Commons Logging and Log4j removed -->
<filter>java.</filter>
<filter>javax.servlet.</filter>
<filter>javax.xml.</filter>
<filter>org.mortbay.</filter>
<filter>org.xml.</filter>
<filter>org.w3c.</filter>
</systemClasses>
</webAppConfig>

Bye and sorry for posting again on this issue.