Android分块上传文件到PHP

Question

我们如何将大文件分块上传到 PHP 服务器，以便在连接断开时，可以随时恢复上传。

具体来说，Android 中需要哪些库来执行此操作？

用户正在从互联网连接缓慢/不稳定的国家/地区上传大文件。谢谢

编辑

更多信息，我目前正在使用 HTTP POST 一次上传整个文件。如下代码所示：

private int uploadFiles(File file) {
        String zipName = file.getAbsolutePath() + ".zip";
        if(!zipFiles(file.listFiles(), zipName)){
            //return -1;
            publishResults(-1);
        }
        //publishProgress(-1, 100);
        HttpURLConnection connection = null;
        DataOutputStream outputStream = null;
        DataInputStream inputStream = null;

        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
        String serverUrl = prefs.getString("serverUrl", "ServerGoesHere"); // todo ensure that a valid string is always stored
        String lineEnd = "\r\n";
        String twoHyphens = "--";
        String boundary = "*****";
        int bytesRead, bytesAvailable, bufferSize;
        byte[] buffer;
        int maxBufferSize = 1 * 1024 * 1024;
        int responseCode = -1;
        try {
            //notif title, undeterministic
            pNotif.setContentText("Zipping complete. Now Uploading...")
                  .setProgress(0, 0, true);
            mNotifyManager.notify(NOTIFICATION_ID, pNotif.build()); // make undeterministic

            //update progress bar to indeterminate
            sendUpdate(0, 0, "Uploading file."); // sendupdate using intent extras

            File uploadFile = new File(zipName);
            long totalBytes = uploadFile.length();
            FileInputStream fileInputStream = new FileInputStream(uploadFile);

            URL url = new URL(serverUrl);
            connection = (HttpURLConnection) url.openConnection();

            connection.setDoInput(true);
            connection.setDoOutput(true);
            connection.setUseCaches(false);

            connection.setRequestMethod("POST");

            connection.setRequestProperty("Connection", "Keep-Alive");
            connection.setRequestProperty("Content-Type",
                    "multipart/form-data;boundary=" + boundary);
            outputStream = new DataOutputStream(connection.getOutputStream());
            outputStream.writeBytes(twoHyphens + boundary + lineEnd);
            outputStream
            .writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\""
                    + zipName + "\"" + lineEnd);
            outputStream.writeBytes(lineEnd);

            bytesAvailable = fileInputStream.available();
            bufferSize = Math.min(bytesAvailable, maxBufferSize);
            buffer = new byte[bufferSize];
            long bytesUploaded = 0;
            bytesRead = fileInputStream.read(buffer, 0, bufferSize);

            while (bytesRead > 0) {
                bytesUploaded += bytesRead;
                outputStream.write(buffer, 0, bufferSize);
                bytesAvailable = fileInputStream.available();
                bufferSize = Math.min(bytesAvailable, maxBufferSize);
                bytesRead = fileInputStream.read(buffer, 0, bufferSize);
                //int percentCompleted = (int) ((100 * bytesUploaded) / totalBytes);
                //publishProgress((int)bytesUploaded/1024, (int)totalBytes/1024);

                System.out.println("bytesRead> " + bytesRead);
            }

            //publishProgress(-2, 1); // switch to clean up
            outputStream.writeBytes(lineEnd);
            outputStream.writeBytes(twoHyphens + boundary + twoHyphens
                    + lineEnd);
            try {
                responseCode = connection.getResponseCode();
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            fileInputStream.close();
            outputStream.flush();
            outputStream.close();
            // Delete the zip file
            new File(zipName).delete();
        } catch (Exception ex) {
            new File(zipName).delete();
            responseCode = -1;
            ex.printStackTrace();
        } 
        return responseCode;
    }

有没有办法修改它以分块发送？我做的大部分研究都不是很清楚，对不起

Answer 1

通过 HTTP 以块的形式上传文件不是一个好主意，因为它是一种无状态协议，您需要为要发送到服务器的每个块建立一个新连接。此外，您必须手动维护此传输之间的状态，并且无法保证文件将按照发送的顺序到达。

您应该使用带有 TCP 套接字的套接字编程，该套接字在整个文件发送之前保持连接。然后，您可以将块推入套接字，它们将无损地到达，并且按照它们被送入套接字的顺序。

Answer 2

我最终使用 SFTP 库实现了可恢复上传。 JSchhttp://www.jcraft.com/jsch/ 我使用 SFTP 上传，库处理可恢复模式。示例代码：

JSch jsch = new JSch();
session = jsch.getSession(FTPS_USER,FTPS_HOST,FTPS_PORT);
session.setPassword(FTPS_PASS);
java.util.Properties config = new java.util.Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
session.connect();
channel = session.openChannel("sftp");
channel.connect();
channelSftp = (ChannelSftp)channel;
channelSftp.cd(FTPS_PATH);

File uploadFile = new File(zipName); // File to upload
totalSize = uploadFile.length(); // size of file

// If part of the file has been uploaded, it saves the number of bytes. Else 0
try {
    totalTransfer = channelSftp.lstat(uploadFile.getName()).getSize();
} catch (Exception e) {
    totalTransfer = 0;
}

// Upload File with the resumable attribute
channelSftp.put(new FileInputStream(uploadFile), uploadFile.getName(), new SystemOutProgressMonitor(), ChannelSftp.RESUME);

channelSftp.exit();
session.disconnect();

有了这个库，我满足了所有要求：可恢复上传和上传进度。