从json数组java获取值的数量

Question

请帮帮我。我有一个json数据：

JSON OBJECT

{
    "id": 3,
    "parentId": 0,
    "bookableResourceId": "046d375d-6240-31e9-acea-c7fd54637608",
    "userId": "4bda1135-2e49-379c-b086-cd082c50eb34",
    "eventId": null,
    "title": "Jaskolski-Ledner",
    "description": "Laudantium fuga et aut voluptas aut est officiis. Distinctio sint iste velit dolor consectetur. Quod et deleniti fugiat. Voluptatum fugiat eum ut ab est.",
    "attendees": [],
    "reminder": 15,
    "rrule": null,
    "exdate": null,
    "checkedIn": true,
    "dateFrom": "2015-02-01T12:00:00Z",
    "dateTo": "2015-02-01T13:30:00Z",
    "dateCreated": "2015-03-19T06:55:35Z",
    "dateUpdated": "2015-03-19T06:55:35Z"
 },
{
        "id": 4,
        "parentId": 0,
        "bookableResourceId": "05162c53-5d9e-3b2a-a578-0789f7adf79e",
        "userId": "60e33324-b609-33fa-bfde-04571c72db58",
        "eventId": null,
        "title": "Barton, Shields and Grady",
        "description": "Quia nobis aut aliquid doloremque. Sit cupiditate itaque totam pariatur commodi. Voluptatem omnis ducimus est mollitia.",
        "attendees": [],
        "reminder": 15,
        "rrule": null,
        "exdate": null,
        "checkedIn": false,
        "dateFrom": "2015-02-01T12:00:00Z",
        "dateTo": "2015-02-01T13:30:00Z",
        "dateCreated": "2015-03-19T06:55:35Z",
        "dateUpdated": "2015-03-19T06:55:35Z"
  }

我需要在json中计算值（所有数组中的值多少）。我能怎么做 它？