title: IllegalStateException: Failed to introspect Class
body: <p>I am trying to implement extension capability on my SpringBoot application where the @ComponentScan is supposed to scan for bean definitions in a separate jar present in the classpath.</p>
  <p>The @ComponentScan looks like below</p>
  <pre><code>@ComponentScan({&quot;com.myapp.rest&quot;,&quot;com.mycompany.search.rest&quot;})
  </code></pre>
  <p>Where package &quot;com.mycompany.search.rest&quot; will be present in an external jar ESExt.jar</p>
  <p>I added below configuration in the <code>server.xml</code> file of my WebSphere Liberty Server to include an external folder for classpath scanning</p>
  <pre><code>&lt;library id=&quot;extention&quot; apiTypeVisibility=&quot;+third-party, -api&quot;&gt;
    &lt;fileset dir=&quot;${server.config.dir}/ext&quot; includes=&quot;*.jar&quot; scanInterval=&quot;5s&quot; /&gt;
  &lt;/library&gt;
  
  &lt;webApplication id=&quot;Myapp&quot; location=&quot;Myapp.war&quot; type=&quot;war&quot; name=&quot;Myapp&quot; contextRoot=&quot;/resources&quot;&gt;
      &lt;classloader commonLibraryRef=&quot;extention&quot; /&gt;
  &lt;/webApplication&gt;
  </code></pre>
  <p>When I deploy my application in a WebSphere Liberty Server, it throws below exception</p>
  <pre><code>[28/9/20 13:43:04:878 IST] 0000002a com.ibm.ws.logging.internal.impl.IncidentImpl                I FFDC1015I: An FFDC Incident has been created: &quot;org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'storeResource': Lookup method resolution failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [com.mycompany.search.rest.StoreResource] from ClassLoader [com.ibm.ws.classloading.internal.AppClassLoader@7a84a757] com.ibm.ws.webcontainer.osgi.DynamicVirtualHost startWebApp&quot; at ffdc_20.09.28_13.43.04.0.log
  </code></pre>
  <p>Below is the output for <code>jar -tf ESExt.jar</code></p>
  <pre><code>META-INF/
  META-INF/MANIFEST.MF
  com/
  com/mycompany/
  com/mycompany/search/
  com/mycompany/search/rest/
  com/mycompany/search/rest/StoreResource.class
  </code></pre>
  <p>What does this exception <code>IllegalStateException: Failed to introspect Class</code> even mean? I cannot even find anything about it in the internet.</p>