java读取properties文件

public class CityNoUtil {   private static Properties message = new Properties();      static{      InputStream is = Thread.currentThread().getContextClassLoader().getResourceAsStream("cityno.properties");      try {         message.load(is);      } catch (IOException e) {         e.printStackTrace();      }   }      public String getMessageByKey(String key){      return message.getProperty(key,AjaxResponse.ERROR);   }}