一、JSONObject和JSONArray的数据表示形式

JSONObject的数据是用 { } 来表示的,

例如:

{ "id" : "123", "courseID" : "huangt-test", "title" : "提交作业", "content" : null  }  

而JSONArray,顾名思义是由JSONObject构成的数组,用 [ { } , { } , …… , { } ] 来表示

例如:

 [{  "id" : "123", "courseID" : "huangt-test", "title" : "提交作业"},
{ "content" : null, "beginTime" : 1398873600000 "endTime" } ]

表示了包含2个JSONObject的JSONArray。

可以看到一个很明显的区别,一个最外面用的是 { } ,一个最外面用的是 [ ] ;

二、如何从字符串jsonString获得JSONObject对象和JSONArray对象

/*json字符串最外层是大括号时:*/
JSONObject jsonObject = new JSONObject(jsonStr); /*json字符串最外层是方括号时:*/
JSONArray jsonArray = new JSONArray(jsonStr);

三、如何从JSONArray中获得JSONObject对象

遇到方括号时,就要先获取JSONArray,然后再循环遍历出JSONObject

大家可以把JSONArray当成一般的数组来对待,只是获取的数据内数据的方法不一样。

 for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
}

注意:

/*JSONObject 获取jsonArray :需要数组的字段名*/
JSONArray jsonArray = jsonObject.getJSONArray("children"); /*jsonArray获取JSONObject : 需要遍历数组*/
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
}

四、通过JsonObject获取JSON内的具体数据:

int mid= jsonObject.getInt ( "id" ) ;
// 这里的mid得到的数据就是123. String mcourse=jsonObject.getString( " courseID") ;
// 这里的mcourse得到的数据就是huangt-test.

示例一:

{
"msg": "",
"code": "succeed",
"login_status": 0,
"mall_uid": "epet_0",
"mall_user": "",
"sys_time": 1494388655,
"push_alias": "",
"push_tags": "version3",
"categorys": [
{
"cateid": 53,
"name": "狗狗玩具",
"children": [
{
"type": "cateid",
"id": "210",
"name": "棉制玩具",
"photo": "http://i.epetbar.com/nowater/cates/2014-03/24/fcab37ead00d77bcdddf7dabe6c817d7.jpg"
},
{
"type": "cateid",
"id": "211",
"name": "橡胶玩具",
"photo": "http://i.epetbar.com/nowater/2016-07/21/14/874299e54a8cf1488d6b1bead8f8e9bb.jpg"
},
{
"type": "cateid",
"id": "212",
"name": "塑料玩具",
"photo": "http://i.epetbar.com/nowater/cates/2014-03/24/df1ed7120376370a4b5badaae61a0a7e.jpg"
},
{
"type": "cateid",
"id": "213",
"name": "手工玩具",
"photo": "http://i.epetbar.com/nowater/cates/2014-03/24/6709410560b999ab37ffb9747bb2ee71.jpg"
},
{
"type": "cateid",
"id": "3088",
"name": "食用玩具",
"photo": "http://i.epetbar.com/nowater/cates/2014-03/24/a5c7619872749790f6d6fd1ff3eccedc.jpg"
},
{
"type": "cateid",
"id": "4157",
"name": "木质玩具",
"photo": "http://i.epetbar.com/nowater/cates/2014-03/24/e9145de044fd5cec4c9b8ed47360d98f.jpg"
},
{
"type": "cateid",
"id": "4188",
"name": "梵米派",
"photo": "http://i.epetbar.com/nowater/cates/2015-07/28/45c339f6acb56364132b92f04b090c5c.jpg"
}
]
}
],
"topadv": {
"advid": "20605",
"src": "https://img2.epetbar.com/nowater/2017-04/05/14/19427a29344bcc0f385ca4718adca02f.jpg",
"title": "红脚丫",
"param": {
"mode": "web",
"param": "http://sale.epet.com/m/mould/activity/ztMTAzOA%3D%3D.html?tid=1038"
}
},
"owner": 53
}

解析如下:

注意:MyData类可以借助GsonFormat类生成实体类。

private List<MyData.CategorysBean.ChildrenBean> parseJSONOrgin(String string) {
List<MyData.CategorysBean.ChildrenBean> childrenBeanList = new ArrayList<MyData.CategorysBean.ChildrenBean>(); try {
JSONObject jsonObject = new JSONObject(string);
JSONArray jsonArray = jsonObject.getJSONArray("categorys");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject1 = jsonArray.getJSONObject(i); JSONArray children = jsonObject1.getJSONArray("children");
for (int j = 0; j < children.length(); j++) {
JSONObject jsonObject2 = children.getJSONObject(j); MyData.CategorysBean.ChildrenBean childrenBean = new MyData.CategorysBean.ChildrenBean();
childrenBean.setName(jsonObject2.getString("name"));
childrenBean.setId(jsonObject2.getString("id"));
childrenBean.setPhoto(jsonObject2.getString("photo"));
childrenBean.setType(jsonObject2.getString("type")); childrenBeanList.add(childrenBean);
}
} } catch (JSONException e) {
e.printStackTrace();
} return childrenBeanList;
}

示例二:

[
{
"id": 582490,
"name": "单车自驾:魔幻张家界",
"photos_count": 128,
"start_date": "2016-04-05",
"end_date": "2016-04-08",
"days": 4,
"level": 4,
"views_count": 55199,
"comments_count": 34,
"likes_count": 441,
"source": "web",
"front_cover_photo_url": "http://p.chanyouji.cn/582490/1468260328216p1andi510ihgkc2f5hk6rf198.jpg",
"featured": false,
"user": {
"id": 313643,
"name": "huchichi",
"image": "http://tva2.sinaimg.cn/crop.0.12.282.282.50/5c5ee839gw1ec7kq4pasrj207v08d3zv.jpg"
}
},
{
"id": 666746,
"name": "【斯里兰卡10天】跨过山和大海",
"photos_count": 122,
"start_date": "2016-12-24",
"end_date": "2017-01-02",
"days": 10,
"level": 3,
"views_count": 33023,
"comments_count": 32,
"likes_count": 471,
"source": "app",
"front_cover_photo_url": "http://p.chanyouji.cn/666746/1485787660939p1b7ntf07u16kdssn1tfl1ck1q1qd.jpg",
"featured": false,
"user": {
"id": 469471,
"name": "宇_RainyK",
"image": "http://a.chanyouji.cn/469471/1460020629.jpg"
}
},
{
"id": 665223,
"name": "上帝自留地探访 : 新西兰——快乐咔嚓声",
"photos_count": 250,
"start_date": "2016-11-30",
"end_date": "2016-12-04",
"days": 5,
"level": 3,
"views_count": 23981,
"comments_count": 30,
"likes_count": 533,
"source": "app",
"front_cover_photo_url": "http://p.chanyouji.cn/1483013211/40p8jhlx7t4e8hntyhp4z31c0.jpg",
"serial_id": 664971,
"serial_position": 1,
"featured": false,
"user": {
"id": 131541,
"name": "片儿川",
"image": "http://a.chanyouji.cn/131541/1483887153821.jpg"
}
},
{
"id": 591454,
"name": "土耳其...我喜欢你,像风走了八千里",
"photos_count": 195,
"start_date": "2016-08-08",
"end_date": "2016-08-22",
"days": 15,
"level": 3,
"views_count": 18822,
"comments_count": 42,
"likes_count": 854,
"source": "web",
"front_cover_photo_url": "http://p.chanyouji.cn/1472368913/9896F012-522E-46C4-9F29-5F6D86C790DB.jpg",
"featured": false,
"user": {
"id": 208609,
"name": "晶晶姑姑娘娘",
"image": "http://a.chanyouji.cn/208609/1493099858.jpg"
}
},
{
"id": 589708,
"name": "浪迹非洲最南——“慢得啦”国闲游之一",
"photos_count": 128,
"start_date": "2016-07-23",
"end_date": "2016-07-24",
"days": 2,
"level": 3,
"views_count": 5858,
"comments_count": 4,
"likes_count": 65,
"source": "web",
"front_cover_photo_url": "http://p.chanyouji.cn/589708/1471963416200p1aqrtl1pq8js1ek0sn913uq1kdmh.jpg",
"serial_id": 589708,
"serial_position": 0,
"featured": false,
"user": {
"id": 103122,
"name": "牵着蜗牛散步的JOY",
"image": "http://tva1.sinaimg.cn/crop.0.17.640.640.50/794bd26ajw8e7tg9nfqb5j20hs0iqmxg.jpg"
}
},
{
"id": 598966,
"name": "霓虹国/留学生 梦游记录",
"photos_count": 88,
"start_date": "2016-08-28",
"end_date": "2017-05-07",
"days": 253,
"level": 3,
"views_count": 16648,
"comments_count": 10,
"likes_count": 72,
"source": "app",
"front_cover_photo_url": "http://p.chanyouji.cn/1476365877/C9B59738-58E8-47C9-BCD1-5F2AC5CC9526.jpg",
"featured": false,
"user": {
"id": 694154,
"name": "Y-dec",
"image": "http://q.qlogo.cn/qqapp/100277927/5475C47B95A36891E2698462184F8785/100"
}
},
{
"id": 544528,
"name": "【我的年假】7 重庆—吃一顿地道火锅",
"photos_count": 385,
"start_date": "2016-08-31",
"end_date": "2016-09-03",
"days": 4,
"level": 3,
"views_count": 37214,
"comments_count": 55,
"likes_count": 530,
"source": "app",
"front_cover_photo_url": "http://p.chanyouji.cn/544528/1474011393910p1asoupfpujrj1rnd5o813qo1jvi5.jpg",
"serial_id": 544528,
"serial_position": 0,
"featured": false,
"user": {
"id": 17010,
"name": "马兰头头2010",
"image": "http://a.chanyouji.cn/17010/1426768814.jpg"
}
},
{
"id": 665311,
"name": "就该这么玩【北海道】",
"photos_count": 118,
"start_date": "2016-12-05",
"end_date": "2016-12-12",
"days": 8,
"level": 3,
"views_count": 24644,
"comments_count": 6,
"likes_count": 108,
"source": "app",
"front_cover_photo_url": "http://p.chanyouji.cn/1484295471/E2B2C32A-C910-490F-9F13-BC9D3B118C1B.jpg",
"featured": false,
"user": {
"id": 544219,
"name": "炘仔~",
"image": "http://a.chanyouji.cn/544219/1489641072.jpg"
}
},
{
"id": 668998,
"name": "漫步成都一一我的寻(熊)猫之旅",
"photos_count": 108,
"start_date": "2017-02-06",
"end_date": "2017-02-12",
"days": 7,
"level": 3,
"views_count": 15222,
"comments_count": 30,
"likes_count": 146,
"source": "app",
"front_cover_photo_url": "http://p.chanyouji.cn/1487129075/720F81CB-EE64-4681-8564-A9A6864AAD33.jpg",
"featured": false,
"user": {
"id": 261578,
"name": "小柠12345",
"image": "http://tva1.sinaimg.cn/crop.27.0.238.238.50/bb9ff9e8gw1eggbljiopfj208w06oaam.jpg"
}
},
{
"id": 297060,
"name": "「吃遍日本」大阪·神户·名古屋",
"photos_count": 125,
"start_date": "2015-04-25",
"end_date": "2015-05-02",
"days": 8,
"level": 4,
"views_count": 56384,
"comments_count": 121,
"likes_count": 948,
"source": "web",
"front_cover_photo_url": "http://p.chanyouji.cn/297060/1440912374444p19tuh3ukup7t1l5c1j0u8r6kfs2.jpg",
"featured": false,
"user": {
"id": 312316,
"name": "CaitlinGao",
"image": "http://tva3.sinaimg.cn/crop.0.0.640.640.50/96246e0bjw8ensjycmsdmj20hs0hsjs7.jpg"
}
}
]

解析如下:

注意:最外层是个方括号。


private List<News> parseJSONOrgin(String json) {
List<News> list = new ArrayList<News>();
try {
JSONArray jsonArray = new JSONArray(json);
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
News news = new News();
news.setSource(jsonObject.getString("source"));
news.setFront_cover_photo_url(jsonObject.getString("front_cover_photo_url"));
news.setName(jsonObject.getString("name"));
news.setStart_date(jsonObject.getString("start_date"));
list.add(news);
}
} catch (JSONException e) {
e.printStackTrace();
}
return list;
}

JSONObject获取Float Double类型数据的准确性:

原始数据:{"status":0,"result":[{"x":114.2307489832,"y":29.579081808346}]}

logger.error(obj.getFloatValue("x"));

114.23075

logger.error(obj.getDoubleValue("x"));

114.23075103759766  

以上2个方法都无法获得完全一致的数值。

Double.valueOf(obj.get("x").toString())

//这段代码可以准确的获取对应数值。 

示例:

homeTopBannerModel.slide_time =Float.valueOf(jSONObjectTopSlide.get("slide_time").toString());
05-07 15:48