从 Android 发送任何 HTTP POST 到我的服务器导致 FileNotFoundException

Question

我有一个服务器运行使用 mongodb、mongoose 和 node.js。所有服务器方法（GET 和 POSTs）都在我的 HTML javascript 上进行了测试，并且它们按预期工作。我也想在我的 android 应用程序中使用这些方法。问题：虽然 GET 方法按预期响应，但所有 POST 请求都会导致 Java.io.FileNotFoundException。我已经尝试了几个没有成功的想法。这是我的应用程序中一个 HTTP POST 请求的代码：

    private class PostNewPlantTask extends AsyncTask<String, Integer, String> {
    String responseString = "";
    int response;
    InputStream is = null;

    protected String doInBackground(String... urls){
        DataOutputStream wr=null;
        try {
            URL url = new URL(urls[0]);  // urls[0] is the url of the http request "http://www..."
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(10000 /* milliseconds */);
            conn.setConnectTimeout(15000 /* milliseconds */);
            conn.setRequestMethod("POST");
            conn.setDoOutput(true);
            conn.setRequestProperty("Content-Type", "application/json");
            conn.setRequestProperty("Content-Type", "application/json");

            // encode base64 from image
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            imageBitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
            byte[] b = baos.toByteArray();
            encodedString = Base64.encodeToString(b, Base64.URL_SAFE | Base64.NO_WRAP);

            // Create JSONObject:
            JSONObject jsonParam = new JSONObject();
            //jsonParam.put("loc", "["+plant_location[0]+","+plant_location[1]+"]");
            jsonParam.put("image", encodedString);
            //Log.d("POSTING PLANT JSON", jsonParam.toString());
            //Log.d("Plant loc",jsonParam.get("loc").toString());

            //wr = new DataOutputStream(conn.getOutputStream());
            //wr.writeBytes(jsonParam.toString());

            //wr.flush();
            //wr.close();


            // Starts the query
            conn.connect();
            response = conn.getResponseCode();
            Log.d("HTTP POST", "#1");

            is = conn.getInputStream();
            Log.d("HTTP POST", "#2");

            // Convert the InputStream into a string
            String contentAsString = readIt(is, 1000);
            Log.d("HTTP POST","#3");
            responseString = contentAsString;
        } catch (Exception e) {
            responseString = "error occured: "+e;
            // Test: write string into textfile

        } finally {
            if (is != null){
                try { is.close();} catch (Exception e) {Log.d("HTTP GET planttypes","Exception occured at closing InputStream: "+e);}
            }
        }
        Log.d("HTTP POST plants", "The response is: " + response + responseString);



        return responseString;
    }

我添加了 Log.d 以缩小 FileNotFoundException 发生的范围。这里是日志：

02-01 15:16:50.088 27382-28809/com.example.openplantmap D/HTTP POST: #1
02-01 15:16:50.096 27382-28809/com.example.openplantmap D/HTTP POST plants: The response is: 500error occured: java.io.FileNotFoundException: https://www......

所以错误 FileNotFoundException 发生在

is = conn.getInputStream();

你知道我的问题是什么以及我必须改变什么才能让它发挥作用吗？

我称之为 post 的部分：

// Submit Button:
    Button btn_submit = (Button) findViewById(R.id.btn_submitPlant);
    btn_submit.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            new PostNewPlantTask().execute("https://www...."); // I prefer not to show the actual url here

            Log.d("SUBMIT PRESSED.","SUBMIT PRESSED");
            // TODO: GIVE FEEDBACK TO THE USER
        }
    });

Answer 1

编辑

而不是wr.writeBytes(jsonParam.toString());

尝试wr.write(URLEncoder.encode(jsonParam.toString(),"UTF-8"));

并取消注释所有写入流的行。

原创

The response is: 500

来自连接的响应是错误 500，或 Internal Server Error。也许您的服务器端脚本有问题，而不是您的 android 代码。我会从那一端进行调试。

您可以使用 getResponseCode() 方法来确定事情是否出错，如果出错，并且错误代码为 400 或以上，响应将包含一个正文，您可以使用 conn.getErrorStream()

从 Android 发送任何 HTTP POST 到我的服务器导致 FileNotFoundException

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