code: public void setPropertiesLocation(String location) {
          Properties properties = load(null, new PathMatchingResourcePatternResolver(), location);
          if (properties != null && properties.size() > 0) {
              configure(properties);
          }
      }
docs: Configures with a properties file, which could be on either the file system
  (file: location) or the class path (classpath: location).