code: protected Map<String, String> getStringDataMap(final JobDataMap jobDataMap){
          Map<String, String> stringMap = new HashMap<>();
          for (Map.Entry<String, Object> entry : jobDataMap.entrySet()) {
              if(entry.getValue() != null){
                  stringMap.put(entry.getKey(), entry.getValue().toString());
              }
          }
          return stringMap;
      }
docs: Convert a {@link org.quartz.JobDataMap} to a {@link java.util.HashMap} with String keys and values
  @param jobDataMap the job data map to be converted
  @return a map with string keys and values