从服务器下载一个没有扩展名的文件

Question

我正在尝试从以下 URL 下载 mp3 文件。我发现了很多关于文件下载的文章和例子。这些示例基于以文件扩展名结尾的 URL，例如：- yourdomain.com/filename.mp3 但我想从以下 url 下载文件，该文件通常不以文件扩展名结尾。

youtubeinmp3.com/download/get/?i=1gsE32jF0aVaY0smDVf%2BmwnIZPrMDnGmchHBu0Hovd3Hl4NYqjNdym4RqjDSAis7p1n5O%2BeXmdwFxK9ugErLWQ%3D%3D

**请注意，我使用上面的 url 原样，没有使用 Whosebug url 格式化方法来轻松理解问题。

** 我尝试了@Arsal Imam 的解决方案如下仍然无效

   btnShowProgress.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // starting new Async Task
            File cacheDir=new File(android.os.Environment.getExternalStorageDirectory(),"Folder Name");
            if(!cacheDir.exists())
                cacheDir.mkdirs();

            File f=new File(cacheDir,"ddedddddd.mp3");
            saveDir=f.getPath();

            new DownloadFileFromURL().execute(fileURL);
        }
    });

而异步任务代码如下

class DownloadFileFromURL extends AsyncTask<String, String, String> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        showDialog(progress_bar_type);
    }

    @Override
    protected String doInBackground(String... f_url) {
        try{

            URL url = new URL(fileURL);
            HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
            int responseCode = httpConn.getResponseCode();

            // always check HTTP response code first
            if (responseCode == HttpURLConnection.HTTP_OK) {
                String fileName = "";
                String disposition = httpConn.getHeaderField("Content-Disposition");
                String contentType = httpConn.getContentType();
                int contentLength = httpConn.getContentLength();

                if (disposition != null) {
                    // extracts file name from header field
                    int index = disposition.indexOf("filename=");
                    if (index > 0) {
                        fileName = disposition.substring(index + 10,
                                disposition.length() - 1);
                    }
                } else {
                    // extracts file name from URL
                    fileName = fileURL.substring(fileURL.lastIndexOf("/") + 1,
                            fileURL.length());
                }

                System.out.println("Content-Type = " + contentType);
                System.out.println("Content-Disposition = " + disposition);
                System.out.println("Content-Length = " + contentLength);
                System.out.println("fileName = " + fileName);

                // opens input stream from the HTTP connection
                InputStream inputStream = httpConn.getInputStream();
                String saveFilePath = saveDir + File.separator + fileName;

                // opens an output stream to save into file
                FileOutputStream outputStream = new FileOutputStream(saveDir);

                int bytesRead = -1;
                byte[] buffer = new byte[BUFFER_SIZE];
                while ((bytesRead = inputStream.read(buffer)) != -1) {
                    outputStream.write(buffer, 0, bytesRead);
                }

                outputStream.close();
                inputStream.close();

                System.out.println("File downloaded");
            } else {
                System.out.println("No file to download. Server replied HTTP code: " + responseCode);
            }
            httpConn.disconnect();

        }catch(Exception e){
            e.printStackTrace();
        }
        return null;
    }

    protected void onProgressUpdate(String... progress) {
        pDialog.setProgress(Integer.parseInt(progress[0]));
    }

    @Override
    protected void onPostExecute(String file_url) {
        dismissDialog(progress_bar_type);

    }
}

Answer 1

使用下面的代码可以很好地处理加密的 URL

public class HttpDownloadUtility {
    private static final int BUFFER_SIZE = 4096;

    /**
     * Downloads a file from a URL
     * @param fileURL HTTP URL of the file to be downloaded
     * @param saveDir path of the directory to save the file
     * @throws IOException
     */
    public static void downloadFile(String fileURL, String saveDir)
            throws IOException {
        URL url = new URL(fileURL);
        HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
        int responseCode = httpConn.getResponseCode();

        // always check HTTP response code first
        if (responseCode == HttpURLConnection.HTTP_OK) {
            String fileName = "";
            String disposition = httpConn.getHeaderField("Content-Disposition");
            String contentType = httpConn.getContentType();
            int contentLength = httpConn.getContentLength();

            if (disposition != null) {
                // extracts file name from header field
                int index = disposition.indexOf("filename=");
                if (index > 0) {
                    fileName = disposition.substring(index + 10,
                            disposition.length() - 1);
                }
            } else {
                // extracts file name from URL
                fileName = fileURL.substring(fileURL.lastIndexOf("/") + 1,
                        fileURL.length());
            }

            System.out.println("Content-Type = " + contentType);
            System.out.println("Content-Disposition = " + disposition);
            System.out.println("Content-Length = " + contentLength);
            System.out.println("fileName = " + fileName);

            // opens input stream from the HTTP connection
            InputStream inputStream = httpConn.getInputStream();
            String saveFilePath = saveDir + File.separator + fileName;

            // opens an output stream to save into file
            FileOutputStream outputStream = new FileOutputStream(saveFilePath);

            int bytesRead = -1;
            byte[] buffer = new byte[BUFFER_SIZE];
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bytesRead);
            }

            outputStream.close();
            inputStream.close();

            System.out.println("File downloaded");
        } else {
            System.out.println("No file to download. Server replied HTTP code: " + responseCode);
        }
        httpConn.disconnect();
    }
}

Answer 2

url returns 302 重定向到实际的 .mp3。浏览器在后台为你做重定向，但在你的应用程序中你需要自己做。这是有关如何使用 HttpUrlConnection http://www.mkyong.com/java/java-httpurlconnection-follow-redirect-example/

执行此操作的示例

Answer 3

如果您事先知道文件的类型，那么您可以从 url 下载没有扩展名的文件。

下载服务.java

public class DownloadService extends IntentService {
    public static final int UPDATE_PROGRESS = 8344;
    private Context context;
    private PowerManager.WakeLock mWakeLock;
    ProgressDialog mProgressDialog;
    String filename;
    File mypath;
    String urlToDownload;
    BroadcastReceiver broadcaster;
    Intent intent1;
    static final public String BROADCAST_ACTION = "com.example.app.activity.test.broadcast";
    public DownloadService() {
        super("DownloadService");   
    }
    @Override
    public void onCreate() {
        // TODO Auto-generated method stub
        super.onCreate();
        intent1 = new Intent(BROADCAST_ACTION);
    }
    @Override
    protected void onHandleIntent(Intent intent) {

        ResultReceiver receiver = (ResultReceiver) intent.getParcelableExtra("receiver");
        try {
            intent1 = new Intent(BROADCAST_ACTION);
            urlToDownload = intent.getStringExtra("url");
            filename= intent.getStringExtra("filename");

            BufferedWriter out;
            try {
                File path=new File("/sdcard/","folder name");
                path.mkdir();
                mypath=new File(path,filename);
                Log.e("mypath",""+mypath);
                if (!mypath.exists()) {
                    out= new BufferedWriter(new FileWriter(mypath));
                    //ut = new OutputStreamWriter(context.openFileOutput( mypath.getAbsolutePath() ,Context.MODE_PRIVATE));
                    out.write("test");
                    out.close();

                } 

            }catch(Exception e){
                e.printStackTrace();
            }
            URL url = new URL(urlToDownload);
            URLConnection connection = url.openConnection();
            connection.connect();
            // this will be useful so that you can show a typical 0-100% progress bar
            int fileLength = connection.getContentLength();

            // download the file
            InputStream input = new BufferedInputStream(connection.getInputStream());
            OutputStream output = new FileOutputStream(mypath);

            byte data[] = new byte[4096];
            long total = 0;
            int count;
            while ((count = input.read(data)) != -1) {
                total += count;
                // publishing the progress....
                Bundle resultData = new Bundle();
                resultData.putInt("progress" ,(int) (total * 100 / fileLength));


                //Log.e("mypath",""+mypath);
                resultData.putString("mypath", ""+mypath);
                receiver.send(UPDATE_PROGRESS, resultData);         

                output.write(data, 0, count);
            }

            output.flush();
            output.close();
            input.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

        Bundle resultData = new Bundle();
        resultData.putInt("progress" ,100);
        resultData.putString("mypath", ""+mypath);
        receiver.send(UPDATE_PROGRESS, resultData);
        intent1.putExtra("progressbar", 100);
        sendBroadcast(intent1);
    }
}

DownloadReceiver.java

public class DownloadReceiver extends ResultReceiver{

    private Context context;
    private PowerManager.WakeLock mWakeLock;
    ProgressDialog mProgressDialog;
    String filename;

    String mypath;
    public DownloadReceiver(Handler handler ,String filename ,Context context) {
        super(handler);

    this.context = context;
        this.filename = filename;

        mProgressDialog = new ProgressDialog(context);
    }

    @Override
    protected void onReceiveResult(int resultCode, Bundle resultData) {
        super.onReceiveResult(resultCode, resultData);
        if (resultCode == DownloadService.UPDATE_PROGRESS) {
            int progress = resultData.getInt("progress");
            mypath = resultData.getString("mypath");
            mProgressDialog.setProgress(progress);
            //Log.e("progress","progress");
            mProgressDialog.setMessage("App name");
            mProgressDialog.setIndeterminate(true);
            mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            mProgressDialog.setCancelable(true);
            if (progress == 100) {
                mProgressDialog.dismiss();

            Log.e("download","download");

            }
        }
    }
}

现在通过以下代码在您的主活动中启动服务：

Intent miIntent = new Intent(mContext, DownloadService.class);
                            miIntent.putExtra("url", url);
                            miIntent.putExtra("filename", id+".mp3");

                            miIntent.putExtra("receiver", new DownloadReceiver(new Handler() , id,mContext));
                            startService(miIntent);

Answer 4

虽然 Volley library 不推荐用于大型下载或流媒体操作，但是，我想分享我的以下工作示例代码。

假设我们只下载 MP3 文件，所以我 hard-code 扩展。当然，我们应该更仔细地检查以避免异常（NullPointer ...），例如检查 headers 是否包含 "Content-Disposition" 键...

希望对您有所帮助！

排球自定义class:

public class BaseVolleyRequest extends Request<NetworkResponse> {

    private final Response.Listener<NetworkResponse> mListener;
    private final Response.ErrorListener mErrorListener;

    public BaseVolleyRequest(String url, Response.Listener<NetworkResponse> listener, Response.ErrorListener errorListener) {
        super(0, url, errorListener);
        this.mListener = listener;
        this.mErrorListener = errorListener;
    }

    @Override
    protected Response<NetworkResponse> parseNetworkResponse(NetworkResponse response) {
        try {
            return Response.success(
                    response,
                    HttpHeaderParser.parseCacheHeaders(response));
        } catch (JsonSyntaxException e) {
            return Response.error(new ParseError(e));
        } catch (Exception e) {
            return Response.error(new ParseError(e));
        }
    }

    @Override
    protected void deliverResponse(NetworkResponse response) {
        mListener.onResponse(response);
    }

    @Override
    protected VolleyError parseNetworkError(VolleyError volleyError) {
        return super.parseNetworkError(volleyError);
    }

    @Override
    public void deliverError(VolleyError error) {
        mErrorListener.onErrorResponse(error);
    }
}

然后在你的Activity:

public class BinaryVolleyActivity extends AppCompatActivity {

    private final Context mContext = this;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_binary_volley);
        RequestQueue requestQueue = Volley.newRequestQueue(mContext);
        String url = "http://www.youtubeinmp3.com/download/get/?i=3sI2yV5mJ0kQ8CnddqmANZqK8a%2BgVQJ%2Fmg3xwhHTUsJKuusOCZUzebuWW%2BJSFs0oz8VTs6ES3gjohKQMogixlQ%3D%3D";
        BaseVolleyRequest volleyRequest = new BaseVolleyRequest(url, new Response.Listener<NetworkResponse>() {
            @Override
            public void onResponse(NetworkResponse response) {                    
                Map<String, String> headers = response.headers;
                String contentDisposition = headers.get("Content-Disposition");
                // String contentType = headers.get("Content-Type");
                String[] temp = contentDisposition.split("filename=");
                String fileName = temp[1].replace("\"", "") + ".mp3";
                InputStream inputStream = new ByteArrayInputStream(response.data);
                createLocalFile(inputStream, fileName);
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e("Volley", error.toString());
            }
        });

        volleyRequest.setRetryPolicy(new DefaultRetryPolicy(DefaultRetryPolicy.DEFAULT_TIMEOUT_MS * 10, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));

        requestQueue.add(volleyRequest);
    }

    private String createLocalFile(InputStream inputStream, String fileName) {
        try {
            String folderName = "MP3VOLLEY";
            String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
            File folder = new File(extStorageDirectory, folderName);
            folder.mkdir();
            File file = new File(folder, fileName);
            file.createNewFile();
            FileOutputStream f = new FileOutputStream(file);
            byte[] buffer = new byte[1024];
            int length;
            while ((length = inputStream.read(buffer)) > 0) {
                f.write(buffer, 0, length);
            }
            //f.flush();
            f.close();
            return file.getPath();
        } catch (IOException e) {
            return e.getMessage();
        }
    }
}

这里是结果截图：

注意：

正如我在下面评论的那样，因为直接下载 Url 会定期更改，您应该使用 Postman for Chrome 等工具检查新的 url，如果它响应二进制而不是网页（已过期 url），然后 Url 有效并且我的代码适用于 Url.

参考以下两张截图：

已过期url:

Un-expired url:

更新获取直接下载的基本逻辑 LINK 来自该站点的文档：

根据Create Your Own YouTube To MP3 Downloader For Free

你可以看看

JSON Example

You can also receive the data in JSON by setting the "format" parameter to "JSON". http://YouTubeInMP3.com/fetch/?format=JSON&video=http://www.youtube.com/watch?v=i62Zjga8JOM

首先，您创建一个 JsonObjectRequest 从上述文件 link 获取响应。然后，在这个JsonObjectRequest的onResponse里面你会得到直接下载link，像这样directUrl = response.getString("link");然后使用BaseVolleyRequest volleyRequest

我刚才讲了直接获取的逻辑url，我看你自己实现吧。祝你好运！

从服务器下载一个没有扩展名的文件

Download a file with no extension from a server

android

url

download

mp3