code: public static Set<String> parseServiceSPIExtensionFile(Resource metaInfServicesEntry) {
  
          Set<String> serviceClazz = new HashSet<String>();
  
          URL metaInfServicesUrl = metaInfServicesEntry == null ? null : metaInfServicesEntry.getURL();
          if (metaInfServicesUrl != null) {
              InputStream is = null;
              BufferedReader bfReader = null;
              InputStreamReader isReader = null;
              try {
                  is = metaInfServicesUrl.openStream();
                  bfReader = new BufferedReader(isReader = new InputStreamReader(is, "UTF-8"));
                  String line;
                  while ((line = bfReader.readLine()) != null) {
                      line = line.trim();
                      if (!line.isEmpty() && !(line.startsWith("#"))) {
                          //just to strip off #
                          int hashPos = line.indexOf("#");
                          if (hashPos != -1) {
                              line = line.substring(0, hashPos);
                          }
                          serviceClazz.add(line);
                      }
                  }
              } catch (IOException e) {
                  throw new CDIRuntimeException(e);
              } finally {
  
                  try {
                      if (is != null) {
                          is.close();
                      }
                      if (isReader != null) {
                          isReader.close();
                      }
                      if (bfReader != null) {
                          bfReader.close();
                      }
                  } catch (IOException e) {
                      throw new CDIRuntimeException(e);
                  }
  
              }
          }
          return serviceClazz;
      }
docs: Read the file META-INF/services/javax.enterprise.inject.spi.Extension and return the extension class names
  
  @param metaInfServicesEntry
  @return