断点续传（适用于Android或Java的Google Drive SDK）

看来MediaHttpUploader不能很好地处理简历上传。原因是“请求上传状态”。Google Drive SDK上传文件中提到的内容始终无法获得内容范围。

因此，解决问题的方法是在上传过程中始终轮询Content-Range。因此，它可以通过“从上次中断的位置恢复上载”来恢复中断的上载。

private String getUploadID(Uri fileUri, String token) {         
    Log.d(LOG_TAG, "[sendResumableHttpRequest] +++");

    String upload_id = "";

    java.io.File fileContent = new java.io.File(fileUri.getPath());
    String fileName = fileContent.getName();
    String contentLength = String.valueOf(fileContent.length());
    String mimeType = getMimeFromURI(fileUri);

    Log.d(LOG_TAG, "[sendResumableHttpRequest] fileName : " + fileName);
    Log.d(LOG_TAG, "[sendResumableHttpRequest] contentLength : " + contentLength);
    Log.d(LOG_TAG, "[sendResumableHttpRequest] mimeType : " + mimeType);

    try {
        String url = "https://www.googleapis.com/upload/drive/v2/files?uploadType=resumable";
        URL obj = new URL(url);
        HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();

        //add reuqest header
        con.setRequestMethod("POST");
        con.setRequestProperty("Authorization", "Bearer " + token);
        con.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
        con.setRequestProperty("X-Upload-Content-Type", mimeType);
        con.setRequestProperty("X-Upload-Content-Length", contentLength);       

        JSONObject jobj = new JSONObject();
        jobj.put("title", fileName);
        byte[] postData = jobj.toString().getBytes();           

        // Send post request
        con.setDoOutput(true);
        DataOutputStream wr = new DataOutputStream(con.getOutputStream());
        wr.write(postData);
        wr.flush();
        wr.close();

        int responseCode = con.getResponseCode();
        String location = con.getHeaderField("Location");
        if (location.contains("upload_id")) {
            String[] uploadParameters = location.split("upload_id");
            upload_id = uploadParameters[1].replace("=", "");
        }

        Log.d(LOG_TAG, "[sendResumableHttpRequest] Response Code : " + responseCode);
        Log.d(LOG_TAG, "[sendResumableHttpRequest] Response Location : " + location);
        Log.d(LOG_TAG, "[sendResumableHttpRequest] Response uploadID : " + upload_id);

        BufferedReader in = new BufferedReader(
                new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();
    } catch (Exception e) {
        e.printStackTrace();            
    }               

    Log.d(LOG_TAG, "[sendResumableHttpRequest] ---");

    return upload_id;
}

private void putFileWithUploadID(Uri fileUri, String token, long range) {       
    Log.d(LOG_TAG, "[putFileWithUploadID] +++");

    java.io.File fileContent = new java.io.File(fileUri.getPath());
    String fileName = fileContent.getName();
    String contentLength = String.valueOf(fileContent.length());
    String mimeType = getMimeFromURI(fileUri);

    Log.d(LOG_TAG, "[putFileWithUploadID] fileName : " + fileName);
    Log.d(LOG_TAG, "[putFileWithUploadID] contentLength : " + contentLength);
    Log.d(LOG_TAG, "[putFileWithUploadID] mimeType : " + mimeType);

    long totalBytesFromDataInputStream = 0;

    try {
        String url = "https://www.googleapis.com/upload/drive/v2/files?uploadType=resumable&upload_id=" + mUploadID;
        URL obj = new URL(url);
        HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();

        //add reuqest header
        con.setRequestMethod("PUT");
        con.setRequestProperty("Authorization", "Bearer " + token);
        con.setRequestProperty("Content-Type", mimeType);
        //con.setFixedLengthStreamingMode(MediaHttpUploader.MINIMUM_CHUNK_SIZE);

        long nextByte = 0;
        if (range == 0) {               
            con.setRequestProperty("Content-Length", contentLength);
        }
        else {
            nextByte = range + 1;
            long remainContentLength = Long.parseLong(contentLength) - nextByte;
            con.setRequestProperty("Content-Length", String.valueOf(remainContentLength));
            String contentRange = "bytes " + (range + 1) + "-" + ( Long.parseLong(contentLength) - 1) + "/" + contentLength;
            con.setRequestProperty("Content-Range", contentRange);

            Log.d(LOG_TAG, "[putFileWithUploadID] Content-Length : " + String.valueOf(remainContentLength));
            Log.d(LOG_TAG, "[putFileWithUploadID] Content-Range : " + contentRange);
        }
        con.setDoOutput(true);          

        DataOutputStream wr = new DataOutputStream(con.getOutputStream());

        @SuppressWarnings("resource")
        DataInputStream inputStream = new DataInputStream(new FileInputStream(fileContent)); 

        int bytes = 0;              
        byte[] bufferOut = new byte[1024];
        while ((bytes = inputStream.read(bufferOut)) != -1) {               
            if (nextByte > 0) {
                nextByte = nextByte - bytes;
                if (nextByte >= 0) continue;
            }
            wr.write(bufferOut, 0, bytes);  
            totalBytesFromDataInputStream += bytes;
        }                                  
        Log.d(LOG_TAG, "[putFileWithUploadID] totalBytesFromDataInputStream:" + totalBytesFromDataInputStream);
        wr.flush();
        wr.close();

        int responseCode = con.getResponseCode();

        Log.d(LOG_TAG, "[putFileWithUploadID] Response Code : " + responseCode);

        BufferedReader in = new BufferedReader(
                new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();

        isUploadCompleted = true;
        isInterrupted = false;
        mLastUploadBytes = 0;
        Log.d(LOG_TAG, "[putFileWithUploadID] isUploadCompleted:" + isUploadCompleted);
        Log.d(LOG_TAG, "[putFileWithUploadID] isInterrupted:" + isInterrupted);
    } catch (Exception e) {
        e.printStackTrace();            
        isInterrupted = true;
        Log.d(LOG_TAG, "[putFileWithUploadID] isInterrupted:" + isInterrupted);
        Log.d(LOG_TAG, "[putFileWithUploadID] totalBytesFromDataInputStream:" + totalBytesFromDataInputStream);
    } finally {
    }

    Log.d(LOG_TAG, "[putFileWithUploadID] ---");
}

private void putFileWithUploadID(Uri fileUri, String token) {   
    putFileWithUploadID(fileUri, token, 0);
}   

private long requestUploadStatus(Uri fileUri, String token) {           
    Log.d(LOG_TAG, "[requestUploadStatus] +++");

    String range_so_far = "0";

    java.io.File fileContent = new java.io.File(fileUri.getPath());
    String contentLength = String.valueOf(fileContent.length());

    Log.d(LOG_TAG, "[requestUploadStatus] contentLength : " + contentLength);

    try {
        String url = "https://www.googleapis.com/upload/drive/v2/files?uploadType=resumable&upload_id=" + mUploadID;
        URL obj = new URL(url);
        HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();

        //add reuqest header
        con.setRequestMethod("PUT");
        con.setRequestProperty("Authorization", "Bearer " + token);
        con.setRequestProperty("Content-Length", "0");
        con.setRequestProperty("Content-Range", "bytes */*");           

        // Send post request
        con.setDoOutput(true);
        DataOutputStream wr = new DataOutputStream(con.getOutputStream());
        wr.flush();
        wr.close();

        int responseCode = con.getResponseCode();
        String rangeHeader = con.getHeaderField("Range");
        if (rangeHeader != null && rangeHeader.length() > 0) {
            String[] range = rangeHeader.split("-");
            range_so_far = range[1];
        }

        Log.d(LOG_TAG, "[requestUploadStatus] Response Code : " + responseCode);
        Log.d(LOG_TAG, "[requestUploadStatus] Response rangeHeader : " + rangeHeader);
        Log.d(LOG_TAG, "[requestUploadStatus] Response range_so_far : " + range_so_far);                        

        BufferedReader in = new BufferedReader(
                new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }

        in.close();
    } catch (Exception e) {
        e.printStackTrace();            
    }               

    Log.d(LOG_TAG, "[requestUploadStatus] ---");

    return Long.parseLong(range_so_far);
}