Mapquest 的 JSON 响应不正确 - Android 应用

Posted 2023-02-16

【中文标题】Mapquest 的 JSON 响应不正确 - Android 应用

【英文标题】：Incorrect JSON response from Mapquest - Android App

【发布时间】：2016-03-21 22:20:36

【问题描述】：

我正在尝试使用 mapquest api 从 mapquest 获取 JSON 对象到 android 应用程序中。 JSON请求规范如下。

POST URL:
http://www.mapquestapi.com/directions/v2/route?key=[YOUR_KEY_HERE]
POST BODY:   

    locations:[
    "State College, PA",
    "Lancaster, PA"
    ]

以下代码成功建立连接，但mapquest的响应不正确。

URL url_mapquest = new URL("http://www.mapquestapi.com/directions/v2/route?key=xxxxxxxxxxxx");

HttpURLConnection connection = (HttpURLConnection) url_mapquest.openConnection();
String urlParameters = "None";
connection.setRequestMethod("POST");
connection.setRequestProperty("USER-AGENT", "Mozilla/5.0");
connection.setRequestProperty("ACCEPT-LANGUAGE", "en-US,en;0.5");
connection.setDoOutput(true);

JSONObject jsonParam = new JSONObject();
try 
    JSONArray list = new JSONArray();
    list.put("State College, PA");
    list.put("Lancaster, PA");
    jsonParam.put("locations", list);
 catch (JSONException e) 
    e.printStackTrace();


System.out.println("JSON String: " + jsonParam.toString());

DataOutputStream dStream = new DataOutputStream(connection.getOutputStream());
dStream.writeBytes(jsonParam.toString());
dStream.flush();
dStream.close();
int responseCode = connection.getResponseCode();

System.out.println("\nSending 'POST' request to URL : " + url_mapquest);
System.out.println("Post parameters : " + urlParameters);
System.out.println("Response Code : " + responseCode);

final StringBuilder output_Mars = new StringBuilder("Request URL : " + url_mapquest);
output_Mars.append(System.getProperty("line.separator") + "Request Parameters : " + urlParameters);
output_Mars.append(System.getProperty("line.separator") + "Response Code : " + responseCode);
output_Mars.append(System.getProperty("line.separator") + "Type : " + "POST");

String line = "";
StringBuilder responseOutput = new StringBuilder();

if (responseCode != HttpURLConnection.HTTP_FORBIDDEN) 
    BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
    System.out.println("output===============" + br);
    while ((line = br.readLine()) != null) 
        responseOutput.append(line);
    
    br.close();
 else 
    responseOutput.append("Response Code 403 Forbidden");

以下是从 android 模拟器捕获的错误响应

代码中可能有什么问题？

---

参考资料：

HttpURLConnection sending JSON POST request to Apache/php JSON.simple example – Read and write JSON JSON with Java Send HTTP POST Request from Java Application to Google Messaging Service MapQuest Platform Web Services Android weather app: JSON, HTTP and Openweathermap Android HTTP Client: GET, POST, Download, Upload, Multipart Request JSON Formatter & Validator

【问题讨论】：

有什么方法可以显示您发布到 api 的 JSON (jsonParam.toString())？

首先看起来你没有包含所需的路由键，但它会帮助看到像 Ultradiv 询问的 JSON。

@Ultradiv (jsonParam.toString() 是 "locations":["State College, PA","Lancaster, PA"]

@RScottCarson，我故意 xxxxx 出路由键

【参考方案1】：

如何将以下内容添加到连接属性中

connection.setRequestProperty("Content-Type", "application/json");
connection.setRequestProperty("Accept", "application/json");

模拟器响应中的以下注释表明应用程序可能未正确接收 JSON 对象。

A JSONObject text must begin with a '' at character 0