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);
   }
}