@Override
  public Map<String, Object> resolve(InputStream in) throws ConfigurationResolveException{
    Properties properties = new Properties();
    try {
      properties.load(in);
    } catch (IOException e) {
      throw new ConfigurationResolveException("parse properties configuration failed.", e);
    }

    Map<String, Object> propertiesMap= new HashMap<String, Object>();
    Set<String> names = properties.stringPropertyNames();
    for (String name : names) {
      if (name.startsWith(PropertyConstants.PROPERTY_KEY_PREFIX)) {
        propertiesMap.put(name, properties.get(name));
      }
    }
    return propertiesMap;
  }
The resolver is used to resolve the environment configuration in properties format.
src/main/java/com/eudemon/ratelimiter/env/resolver/PropertiesPropertySourceResolver.java