How to use third party libraries in my instrumentation?

[eggitayi]

My otel javaagent extension instuments spring mvc application to extract post reqeust's body.
Then in my AttributesExtractor, i use com.jayway.jsonpath.JsonPath library to do this.
But it doesn's work, seem that whole extension stop running.
If i commemt out all about com.jayway.jsonpath.JsonPath code, extension can print some debug strings.
So why and how?

I tried shaodwjar to put third party into a single extension jar, but still the same.

  id("otel.javaagent-instrumentation")
  id("com.github.johnrengelman.shadow")
}

muzzle {
  pass {
    group.set("org.springframework")
    module.set("spring-webmvc")
    versions.set("[3.1.0.RELEASE,6)")
    // these versions depend on org.springframework:spring-web which has a bad dependency on
    // javax.faces:jsf-api:1.1 which was released as pom only
    skip("1.2.1", "1.2.2", "1.2.3", "1.2.4")
    // 3.2.1.RELEASE has transitive dependencies like spring-web as "provided" instead of "compile"
    skip("3.2.1.RELEASE")
    extraDependency("javax.servlet:javax.servlet-api:3.0.1")
    assertInverse.set(true)
  }

}

dependencies {
  implementation("com.jayway.jsonpath:json-path:2.8.0")
  compileOnly("org.springframework:spring-web:4.1.7.RELEASE")
  compileOnly("org.springframework:spring-webmvc:3.1.0.RELEASE")
  compileOnly("javax.servlet:javax.servlet-api:3.1.0")
}
tasks {
  shadowJar {
    mergeServiceFiles()
  }
}```

[eggitayi]

I added a isHelperClass method, it seems work.

@Override
  public boolean isHelperClass(String className) {
    return className.startsWith("com.jayway.jsonpath.") ||
        className.startsWith("net.minidev") || className.startsWith("org.objectweb.asm") ||
        className.startsWith("org.slf4j");

  }

So, what does Helper Class mean? and how does it work?