String JSONObject JSONArray List<實體類>轉換

JSON使用阿裡的fastJson為依賴包

gradle依賴管理如下：

compile group: \'com.alibaba\', name: \'fastjson\', version:\'1.2.41\'

1、String轉JSONObject

前言：String 是JSONObject格式的字元串

eg:

JSONObject jSONObject = JSONObject.parseObject(String);

2、String轉JSONArray

前言：String 是JSONArray格式的字元串

eg:

JSONArray jsonArray= JSONArray.parseArray(String);

3、JSONObject中的數組提取為JSONArray

eg:

{
    "AreaName": "北京",
    "CityId": 110100,
    "NoMarket": false,
    "OldCityId": 646,
    "Pinyin": "beijing",
    "ProvinceId": 110000,
    "Result": [
        {
            "ItemName": "優惠",
            "ItemUrl": "/list/a646c12-1.html",
            "Title": "Stelvio 钜惠23.4萬起",
            "Url": "//www.autohome.com.cn/market/201904/100223763.html"
        },
        {
            "ItemName": "優惠",
            "ItemUrl": "/list/a646c12-1.html",
            "Title": "馬駒橋林肯中心年中大促",
            "Url": "//www.autohome.com.cn/market/201906/100230932.html"
        },
        {
            "ItemName": "優惠",
            "ItemUrl": "/list/a646c12-1.html",
            "Title": "星越平價銷售13.58萬元起",
            "Url": "//www.autohome.com.cn/dealer/201906/367011492.html"
        },
        {
            "ItemName": "優惠",
            "ItemUrl": "/list/a646c12-1.html",
            "Title": "哈弗F5限時優惠8000元",
            "Url": "//www.autohome.com.cn/dealer/201906/366897778.html"
        },
        {
            "ItemName": "優惠",
            "ItemUrl": "/list/a646c12-1.html",
            "Title": "購元新能源價格暫無優惠",
            "Url": "//www.autohome.com.cn/dealer/201906/366897034.html"
        },
        {
            "ItemName": "優惠",
            "ItemUrl": "/list/a646c12-1.html",
            "Title": "瑞虎3xe冰點價促銷中！",
            "Url": "//www.autohome.com.cn/dealer/201906/366889724.html"
        },
        {
            "ItemName": "優惠",
            "ItemUrl": "/list/a646c12-1.html",
            "Title": "購奔奔EV現钜惠5.1萬元",
            "Url": "//www.autohome.com.cn/dealer/201906/366843204.html"
        },
        {
            "ItemName": "優惠",
            "ItemUrl": "/list/a646c12-1.html",
            "Title": "購寶馬7系價格暫無優惠",
            "Url": "//www.autohome.com.cn/dealer/201906/366588080.html"
        },
        {
            "ItemName": "預定",
            "ItemUrl": "/list/a646c14-1.html",
            "Title": "途觀L價格直降7.6萬元",
            "Url": "//www.autohome.com.cn/dealer/201906/366568937.html"
        },
        {
            "ItemName": "預定",
            "ItemUrl": "/list/a646c14-1.html",
            "Title": "購凱迪拉克XTS降8萬",
            "Url": "//www.autohome.com.cn/dealer/201906/366500646.html"
        },
        {
            "ItemName": "預定",
            "ItemUrl": "/list/a646c14-1.html",
            "Title": "漢蘭達可試駕購車無優惠",
            "Url": "//www.autohome.com.cn/dealer/201906/366384207.html"
        },
        {
            "ItemName": "預定",
            "ItemUrl": "/list/a646c14-1.html",
            "Title": "寶馬M4價格穩定無優惠",
            "Url": "//www.autohome.com.cn/dealer/201906/366156789.html"
        },
        {
            "ItemName": "預定",
            "ItemUrl": "/list/a646c14-1.html",
            "Title": "奧迪A8促銷直降26.33萬元",
            "Url": "//www.autohome.com.cn/dealer/201906/366925378.html"
        },
        {
            "ItemName": "預定",
            "ItemUrl": "/list/a646c14-1.html",
            "Title": "英菲尼迪Q50L可降6.3萬",
            "Url": "//www.autohome.com.cn/dealer/201906/366863516.html"
        },
        {
            "ItemName": "預定",
            "ItemUrl": "/list/a646c14-1.html",
            "Title": "帝豪新能源價格降8.25萬",
            "Url": "//www.autohome.com.cn/dealer/201906/366877669.html"
        },
        {
            "ItemName": "預定",
            "ItemUrl": "/list/a646c14-1.html",
            "Title": "撼路者在售現钜惠5萬",
            "Url": "//www.autohome.com.cn/dealer/201906/366912121.html"
        }
    ]
}

提取Result對應的數組

JSONArray jsonArray= jsonObject.getJSONArray("Result");

4、JSONArray提取為JSONObject

eg:

JSONObject jsonObject = jsonArray.getJSONObject(0);

5、JSONObject擷取value

1、object.getString("key")

2、object.get("key")

6、擷取JSONObject的ket value

JSONArray dateArr = new JSONArray();
        Set<String> key = dateArr .keySet();
        for (String keyObj:key) {
            JSONArray hisData = history.getJSONArray(keyObj);           
        }

7、周遊JSONArray

第一種for循環
                JSONArray seriesArr = new JSONArray();
                for(int i=0;i<seriesArr .size();i++){
                    JSONObject object = eggsArr.getJSONObject(i);
                }


第二種for增強
                JSONArray pzListArr = new JSONArray();
                for (Object obj:pzListArr) {
                    JSONObject dataObj = JSONObject.parseObject(obj.toString());
                }

8、Map轉為JSON格式的字元串

Map<String, Object> paraMap = new HashMap<String, Object>();

JSONObject.toJSONString(paraMap)

自動過濾參數為null的數值

結果：

8、javaBean轉為JSONObject

JSONObject.parseObject(JSONObject.toJSON(javaBean對象).toString())；

9、List<實體類>轉String

import com.alibaba.fastjson.JSONObject;

List<實體類> value1 = 。。。。。。

JSONObject.toJSONString(value1 )10、JSONArray轉List<實體類>

看你開心用哪個，object和array的差別沒有細究

10、JSONArray轉List<實體類>

import com.alibaba.fastjson.JSONArray;
JSONArray objects = JSONArray.parseArray(categoryConstantInfoFromRedis);
List<實體類> categoryConstantInfos = objects.toJavaList(實體類名.class);
衆裡尋他千百度！！！toJavaList

找不到方法的時候，去看看JSONArray，JSONObject的源碼，很多都有封裝好的，你不會失望的

String JSONObject JSONArray List&lt;實體類&gt;轉換

String JSONObject JSONArray List<實體類>轉換