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);
        }
    }