java - Android:显示真实上传进度百分比

Question

我需要将生成的大型 pdf 文件上传到服务器并向用户显示上传进度。但问题是我从OutputStream获取的百分比并不是真正的进度，因为OutputStream进度100%后，仍然无法从服务器获取响应代码(需要等待更多)

请帮我解决这个问题。谢谢。

** 了解更多信息:总上传时间为 15 分钟，但进度百分比在一秒内完成。

class UploadPdf extends AsyncTask<String, Integer, String> {

    private Activity activity;
    private String orderId = "";
    private String filenamepdf = "";
    private String filenamezip = "";
    private int dpi = 640;
    public ImageCreator mImageCreator;

    public UploadPdf(Activity activity) {
        this.activity = activity;
    }

    @Override
    protected String doInBackground(String... strings) {
        orderId = strings[0];
        filenamepdf = orderId + ".pdf";

        String uploadStatus = uploadFileToServer();
        return uploadStatus;
    }

    @Override
    protected void onProgressUpdate(Integer... progress) {
        //Update progress
        updateProgress(progress[0]);
    }

    @Override
    protected void onPostExecute(String result) {
        //Show result
        try {
            JSONObject obj = new JSONObject(result);
            if(obj.getString("status").equals("success")) {
                uploadSuccess();
            } else {
                errorContainer.setVisibility(View.VISIBLE);
            }

        } catch (Exception ex) {
            errorContainer.setVisibility(View.VISIBLE);
        }
    }

    private String uploadFileToServer() {
        Log.d(LOGTAG, "uploadFileToServer");
        String urlString = Constants.API_BASE_URL + Constants.API_CREATE_UPLOAD_FILE;

        String response = null;
        String attachmentName = "attachment";
        String attachmentFileName = "attachment";
        String crlf = "\r\n";
        String twoHyphens = "--";
        String boundary = "*****";

        try {
            File file = new File(filenamepdf);
            MultipartUtility multipart = new MultipartUtility(urlString, "UTF-8", getApplicationContext());

            multipart.addFormField("order_id", orderId);
            multipart.addFilePart("album_image_path", file);

            List<String> responseReturn = multipart.finish();
            Log.e(LOGTAG, "SERVER REPLIED:");
            response = "";
            for (String line : responseReturn) {
                Log.e(LOGTAG, "Upload Files Response:::" + line);
                response += line;
            }
        } catch (Exception ex) {
            Log.e(LOGTAG, "Failed:" + ex.getMessage());
        }

        Log.e(LOGTAG, "Response:" + response);
        return response;
    }

    public class MultipartUtility {
        private final String LOGTAG = "MultipartUtility";
        private final String boundary;
        private static final String LINE_FEED = "\r\n";
        private HttpURLConnection httpConn;
        private String charset;
        private OutputStream outputStream;
        private PrintWriter writer;
        Context context;

        /**
         * This constructor initializes a new HTTP POST request with content type
         * is set to multipart/form-data
         *
         * @param requestURL
         * @param charset
         * @throws IOException
         */
        public MultipartUtility(String requestURL, String charset, Context context)
                throws IOException {
            this.charset = charset;
            this.context = context;

            // creates a unique boundary based on time stamp
            boundary = "===" + System.currentTimeMillis() + "===";
            URL url = new URL(requestURL);
            httpConn = (HttpURLConnection) url.openConnection();
            httpConn.setUseCaches(false);
            httpConn.setDoOutput(true);    // indicates POST method
            httpConn.setDoInput(true);
            httpConn.setRequestProperty("Content-Type",
                    "multipart/form-data; boundary=" + boundary);
            outputStream = httpConn.getOutputStream();
            writer = new PrintWriter(new OutputStreamWriter(outputStream, charset),
                    true);
        }

        /**
         * Adds a form field to the request
         *
         * @param name  field name
         * @param value field value
         */
        public void addFormField(String name, String value) {
            Log.d(LOGTAG, "name: " + name + ", value: " + value);
            writer.append("--" + boundary).append(LINE_FEED);
            writer.append("Content-Disposition: form-data; name=\"" + name + "\"")
                    .append(LINE_FEED);
            writer.append("Content-Type: text/plain; charset=" + charset).append(
                    LINE_FEED);
            writer.append(LINE_FEED);
            writer.append(value).append(LINE_FEED);
            writer.flush();
        }


        /**
         * Adds a upload file section to the request
         *
         * @param fieldName  name attribute in <input type="file" name="..." />
         * @param uploadFile a File to be uploaded
         * @throws IOException
         */
        public void addFilePart(String fieldName, File uploadFile) throws IOException {
            String fileName = uploadFile.getName();
            Log.d(LOGTAG, fieldName);
            writer.append("--" + boundary).append(LINE_FEED);
            writer.append(
                    "Content-Disposition: form-data; name=\"" + fieldName
                            + "\"; filename=\"" + fileName + "\"")
                    .append(LINE_FEED);
            writer.append(
                    "Content-Type: "
                            + URLConnection.guessContentTypeFromName(fileName))
                    .append(LINE_FEED);
            writer.append("Content-Transfer-Encoding: binary").append(LINE_FEED);
            writer.append(LINE_FEED);
            writer.flush();

            FileInputStream inputStream = new FileInputStream(uploadFile);

            byte[] bytes = new byte[(int) uploadFile.length()];
            int byteLength = bytes.length;
            byte[] buffer = new byte[4096];
            int bytesRead = -1;
            int sendByte = 0;
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bytesRead);
                sendByte += bytesRead;
                int progress = (int)(sendByte / (float) byteLength * 100);
                Log.d(LOGTAG, "bytesRead: " + bytesRead + ", byteLength: " + byteLength + ", progress: " + progress);
                publishProgress(progress);
            }
            outputStream.flush();
            Log.d(LOGTAG, "Read byte finish");
            outputStream.close();
            Log.d(LOGTAG, "Close output stream");

            inputStream.close();
            Log.d(LOGTAG, "Close input stream");
            writer.append(LINE_FEED);
            writer.flush();
            Log.d(LOGTAG, "Writer flushed");
        }
        public void addHeaderField(String name, String value) {
            writer.append(name + ": " + value).append(LINE_FEED);
            writer.flush();
        }

        public List<String> finish() throws IOException {
            Log.d(LOGTAG, "Finishing");
            List<String> response = new ArrayList<String>();
            writer.append(LINE_FEED).flush();
            Log.d(LOGTAG, "Line feed flushed");
            writer.append("--" + boundary + "--").append(LINE_FEED);
            Log.d(LOGTAG, "Last line flushed");
            writer.close();
            Log.d(LOGTAG, "Writer closed");

            // checks server's status code first
            int status = httpConn.getResponseCode();
            Log.d(LOGTAG, "Server returned status: " + status);
            if (status == HttpURLConnection.HTTP_OK) {
                BufferedReader reader = new BufferedReader(new InputStreamReader(
                        httpConn.getInputStream()));
                String line = null;
                while ((line = reader.readLine()) != null) {
                    response.add(line);
                }
                reader.close();
                httpConn.disconnect();
            } else {
                throw new IOException("Server returned non-OK status: " + status);
            }
            return response;
        }
    }
}

Answer 1

首先，我建议使用 OKHTTP MultipartBody，这是更好的 api，这里使用的是同一个类，您可以像使用 MultiPart 实用程序一样使用

public class MultipartRequest {
    public Context caller;
    public MultipartBody.Builder builder;
    private OkHttpClient client;

    public MultipartRequest(Context caller) {
        this.caller = caller;
        this.builder = new MultipartBody.Builder();
        this.builder.setType(MultipartBody.FORM);
        this.client = new OkHttpClient();
    }

    public void addString(String name, String value) {
        this.builder.addFormDataPart(name, value);
    }

    public void addFile(String name, String filePath, String fileName) {
        this.builder.addFormDataPart(name, fileName, RequestBody.create(
                MediaType.parse("image/jpeg"), new File(filePath)));
    }

    public void addTXTFile(String name, String filePath, String fileName) {
        this.builder.addFormDataPart(name, fileName, RequestBody.create(
                MediaType.parse("text/plain"), new File(filePath)));
    }

    public void addZipFile(String name, String filePath, String fileName)
    {
        this.builder.addFormDataPart(name, fileName, RequestBody.create(
                MediaType.parse("application/zip"), new File(filePath)));
    }

    public String execute(String url,String header) {
        RequestBody requestBody = null;
        Request request = null;
        Response response = null;

        int code = 200;
        String strResponse = null;

        try {
            requestBody = this.builder.build();
            request = new Request.Builder().header("Authorization", header)
                    .url(url).post(requestBody).build();



            Log.e("::::::: REQ :: " , ""+request);
            response = client.newCall(request).execute();
            Log.e("::::::: response :: " ,""+ response);

            if (!response.isSuccessful())
                throw new IOException();

            code = response.networkResponse().code();

            if (response.isSuccessful()) {
                strResponse = response.body().string();
            } else {

            }
        } catch (Exception e) {
            Log.e("Exception", ""+e);

        } finally {
            requestBody = null;
            request = null;
            response = null;
            builder = null;
            if (client != null)
                client = null;
            System.gc();
        }
        return strResponse;
    }
}

现在为了解决您对如何取得进展的担忧，这里提供了一个解决方案，请查看一下

OKHTTP 3 Tracking Multipart upload progress

这确实是一个很好的解决方案。