I'm having a similar struggle. I tried to add my dependency JAR files via the "Additional groovy classpath" mechanism but its not working. I'm stuck doing horrible things like

this.class.classLoader.rootLoader.addURL(new URL("file:///C:\\dependencies\\xws-security.jar"))
def cls15 = Class.forName("com.sun.xml.wss.impl.callback.PasswordCallback").newInstance()

Other unsuccessful attempts include

• Putting the files in ${WORKSPACE}/.groovy/lib (http://groovy.codehaus.org/Running)
• Launching using GroovyShell with a custom CompilerConfiguration but then I lost the "manager" property that the Groovy Postbuild plugin binds. (http://stackoverflow.com/questions/8721971/how-to-create-a-groovyshell-object-with-context-apps-classpath/10588798#10588798)

The code involved with handling the "Additional groovy classpath" seems like it should support adding dependency JARs... https://github.com/jenkinsci/groovy-postbuild-plugin/blob/master/src/main/java/org/jvnet/hudson/plugins/groovypostbuild/GroovyPostbuildRecorder.java

@Frank Please let me know if you find a better workaround.

No work around at all . . . I'll have to take a look at yours - THANK YOU.

My goal is to make ODBC work from a Java Post Build Plugin . . . so far, no luck . . . I'll try your solution soon and report.

But it will be a few days . . . I got side tracked by other high priority work.

When I actually got around to trying this, I could not make it work.

While the code worked fine when run as a Groovy script on its own, once it was inside the Jenkins JVM, for some reason "rootLoader" was null. I'm not enough of a Groovy Guru to understand the difference between the two loaders, but I am still stumped and have no workaround.

Cool . . . just made it to my SQL server from inside the plugin with the following change instead of "this":

manager.hudson.class.classLoader.addURL(new URL("file:///" + filePath))

Frank, how did that work? For me that says:

groovy.lang.MissingPropertyException: No such property: manager for class: Script1

fmerrow, bviktor would be higly interested in that, too

I've been having the same problem. I'm using v2.2 of the plugin. I've tried using the "Additional Classpath" fields, gone into the Jenkins file in /etc/sysconfig and added a "-cp" options to the JENKINS_JAVA_OPTIONS setting, and tried using the classload in the form: manager.hudson.class.classLoader.addURL(new URL("file:///" + filePath))

None of it seemed to work. In the end I had to create a "Trigger parameterized build on other project" then specify my script in a Build step. The classpath variables appeared to work there.

I was able to get the following to work

in my postbuild task

this.class.classLoader.parseClass("/home/jenkins/GitlabPostbuildReporter.groovy")
GitlabPostbuildReporter.newInstance(manager).report()

in my file on disk at /home/jenkins/GitlabPostbuildReporter.groovy

class GitlabPostbuildReporter {
  def manager
  public GitlabPostbuildReporter(manager){
    if(manager == null) {
      throw new RuntimeException("Manager object musn't be null")
    }
    this.manager = manager
  }
  public def report() {
    // do work with manager object
  }
}