code: private void searchJars(Container moduleContainer, List<String> classList) {
          Entry webinfLibEntry = moduleContainer.getEntry("WEB-INF/lib");
  
          //No need to look for jars if there is no WEB-INF/lib
          if (webinfLibEntry == null)
              return;
  
          try {
              Container c = webinfLibEntry.adapt(Container.class);
              Iterator<Entry> ie = c.iterator();
              while (ie.hasNext()) {
                  Entry current = ie.next();
                  if (current.getName().endsWith(".jar")) {
                      //Again, convert to a container
                      try {
                          Container jarContainer = current.adapt(Container.class);
                          if (jarContainer != null) {
                              addConfigFileBeans(jarContainer.getEntry("META-INF/faces-config.xml"), classList);
  
                              //Spec says we have to look for any file in META-INF that ends with .faces-config.xml
                              Entry metainf = jarContainer.getEntry("META-INF");
                              if (metainf == null)
                                  return;
  
                              Container metainfContainer = metainf.adapt(Container.class);
                              Iterator<Entry> metaInfIterator = metainfContainer.iterator();
  
                              while (metaInfIterator.hasNext()) {
                                  Entry currentEntry = metaInfIterator.next();
                                  if (currentEntry.getName().endsWith(".faces-config.xml")) {
                                      addConfigFileBeans(currentEntry, classList);
                                  }
                              }
  
                          }
  
                      } catch (UnableToAdaptException e) {
                          if (log.isLoggable(Level.FINE)) {
                              log.logp(Level.FINE, CLASS_NAME, "searchJars", "unable to adapt jar or META-INF dir in jar named " + current.getName() + " to a container", e);
                          }
                      }
                  }
              }
          } catch (UnableToAdaptException e) {
              if (log.isLoggable(Level.FINE)) {
                  log.logp(Level.FINE, CLASS_NAME, "searchJars", "unable to adapt WEB-INF/lib to a container", e);
              }
          }
      }
docs: Search inside jars for META-INF/faces-config.xml or META-INF/*.faces-config.xml