关于Properties 集 添加数据 遍历数据

 public static void fun1(){
         Properties v = new Properties();
         v.setProperty("a","1");
         v.setProperty("a1","11");
         v.setProperty("a2","111");
         System.out.println(v);
         // 获取键值
         String s = v.getProperty("a");
         // 根据 键 获取 值
         System.out.println(s);
         //将集合中的键  存储到Set集合
         Set<String> set = v.stringPropertyNames();
         for(String k:set){
             //System.out.println(k);
             String value = v.getProperty(k);
             System.out.println(k+":"+value);
         }
     }