如何在 Android 中使用 HTTP POST 将图像作为 JSON 中的 base64 字符串发送？答案

【问题标题】：How to send image as base64 string in JSON using HTTP POST in Android?如何在 Android 中使用 HTTP POST 将图像作为 JSON 中的 base64 字符串发送？
【发布时间】：2015-08-26 10:12:46
【问题描述】：

我需要使用 HttpPost 将 json 请求发送到服务器。这是我当前的代码：

public static String makeRequest(String uri, String json) {
        HttpURLConnection urlConnection;

        String data = json;
        String result = null;
        try {
            //Connect 
            urlConnection = (HttpURLConnection) ((new URL(uri).openConnection()));
            urlConnection.setDoOutput(true);
            urlConnection.setRequestProperty("Content-Type", "application/json");
            urlConnection.setRequestProperty("Accept", "application/json");
            urlConnection.setRequestMethod("POST");
            urlConnection.connect();

            //Write
            OutputStream outputStream = urlConnection.getOutputStream();
            BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
            writer.write(data);
            writer.close();
            outputStream.close();

            //Read
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream(), "UTF-8"));

            String line = null;
            StringBuilder sb = new StringBuilder();

            while ((line = bufferedReader.readLine()) != null) {
                System.out.println("Uploading............");
                sb.append(line);
            }

            bufferedReader.close();
            result = sb.toString();
            System.out.println("Response : " +result);

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return result;
    }

但它给了我 400，这意味着错误的请求。

注意：当base64路径较小时，只有它起作用，否则不起作用。请帮帮我。

【问题讨论】：

base64 路径在起作用时是什么样子的？什么时候没有？
base64路径小的话可以用，base64路径大就不行
你能举一个对你有用/没用的实际路径的例子吗？
当我检查浏览器时，两条路径都有效。但是路径长度是否太长，然后我收到“找不到文件”之类的错误

标签： android json base64 http-post

【解决方案1】：

请使用此代码：

try {

                        HttpURLConnection urlConnection;


                        String result = "";
                        try {
                            String data ="";
                            data = jsonObj.toString();
                            //          String temp=URLEncoder.encode(uri, "UTF-8");
                            URL url = new URL(WebServiceConstants.getMethodUrl(WebServiceConstants.METHOD_UPDATEVENDER));
                            urlConnection = (HttpURLConnection) ((url.openConnection()));
                            urlConnection.setDoInput(true);
                            urlConnection.setDoOutput(true);
                            urlConnection.setUseCaches(false);
                            urlConnection.setChunkedStreamingMode(1024);

                            urlConnection.setRequestProperty("Content-Type", "application/json");
                            urlConnection.setRequestProperty("Accept", "application/json");
                            urlConnection.setRequestMethod("POST");
                            urlConnection.connect();

                            //Write
                            OutputStream outputStream = urlConnection.getOutputStream();
                            BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
                            writer.write(data);
                            writer.close();
                            outputStream.close();

                            //Read
                            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream(), "UTF-8"));

                            String line = null;
                            StringBuilder sb = new StringBuilder();

                            while ((line = bufferedReader.readLine()) != null) {
                                System.out.println("Uploading............");
                                sb.append(line);
                            }

                            bufferedReader.close();
                            _responseMain = sb.toString();
                            System.out.println("Response of Image Upload : " +_responseMain);


                        } catch (UnsupportedEncodingException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                        //                      makeRequest(WebServiceConstants.getMethodUrl(WebServiceConstants.METHOD_UPDATEVENDER), jsonObj.toString());
                    } 
                    catch (Exception e) {
                        // TODO: handle exception
                        e.printStackTrace();

                        runOnUiThread( new Runnable() {
                            public void run() 
                            {
                                Constant.showAlertDialog("Message",getResources().getString(R.string.communicationError), VendorEditProfile.this, false);
                            }
                        });

                    }

【讨论】：