Android之Json解析

雨点打透心脏的1/2处 2022-09-23 04:51 265阅读 0赞

JSON返回示例：  
\{ /\*JSONObject\*/  
    "resultcode": "200",  
    "reason": "SUCCESSED!",  
    "result": \[ /\*JSONArray\*/  
        \{ /\*JSONObject\*/  
            "city": "苏州",  /\*城市\*/  
            "PM2.5": "73",  /\*PM2.5指数\*/  
            "AQI": "98",    /\*空气质量指数\*/  
            "quality": "良", /\*空气质量\*/  
            "PM10": "50",/\*PM10\*/  
            "CO": "0.79",  /\*一氧化碳\*/  
            "NO2": "65",  /\*二氧化氮\*/  
            "O3": "28",    /\*臭氧\*/  
            "SO2": "41",  /\*二氧化硫\*/  
            "time": "2014-12-26 11:48:40"/\*更新时间\*/    
        \}  
    \],  
    "error\_code": 0  
\}  
  
实例：JSONDemo  
运行效果：

![SouthEast][]

主要代码片段：

protected void onPostExecute(String result) {  
            if (result != null) {  
                try {  
                    JSONObject jsonObject = new JSONObject(result);  
                    int resultCode = jsonObject.getInt("resultcode");  
                    if (resultCode == 200) {  
                        JSONArray resultJsonArray = jsonObject.getJSONArray("result");  
                        JSONObject resultJsonObject = resultJsonArray.getJSONObject(0);  
                        String output = context.getString(R.string.city) + ": " + resultJsonObject.getString("city") + "\n"  
                                + context.getString(R.string.PM25) + ": " + resultJsonObject.getString("PM2.5") + "\n"  
                                + context.getString(R.string.AQI) + ": " + resultJsonObject.getString("AQI") + "\n"  
                                + context.getString(R.string.quality) + ": " + resultJsonObject.getString("quality") + "\n"  
                                + context.getString(R.string.PM10) + ": " + resultJsonObject.getString("PM10") + "\n"  
                                + context.getString(R.string.CO) + ": " + resultJsonObject.getString("CO") + "\n"  
                                + context.getString(R.string.NO2) + ": " + resultJsonObject.getString("NO2") + "\n"  
                                + context.getString(R.string.O3) + ": " + resultJsonObject.getString("O3") + "\n"  
                                + context.getString(R.string.SO2) + ": " + resultJsonObject.getString("SO2") + "\n"  
                                + context.getString(R.string.time) + ": " + resultJsonObject.getString("time") + "\n";  
                        tv_result.setText(output);  
                    } else if (resultCode == 202) {  
                        String reason = jsonObject.getString("reason");  
                        tv_result.setText(reason);  
                    } else {  
                        Toast.makeText(context, "查询失败",  
                                Toast.LENGTH_LONG).show();  
                        tv_result.setText("");  
                    }  
                } catch (JSONException e) {  
                    // TODO Auto-generated catch block  
                    e.printStackTrace();  
                }  
            } else {  
                Toast.makeText(context, "查询失败",  
                                        Toast.LENGTH_LONG).show();  
                tv_result.setText("");  
            }  
        }

分析：key值 'result' 后面对应的是数组，所以上面代码用法是getJSONArray； 数组当中又是一个\{ \}对象，所以代码中就是 resultJsonArray.getJSONObject(0);  这句 。 总而言之记住一个原则，value是什么类型，那么就用什么类型去获取。

[SouthEast]: /images/20220721/d5c759dd0c014a569745919b89f677b2.png