Question

我尝试从以下网址下载mp3文件。我找到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网址，例如： - yourdomain.com/filename.mp3但我想从以下网址下载文件，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，而不使用Stackoverflow网址格式化方法来轻松理解这个问题。

** 我尝试了@Arsal Imam的解决方案如下仍然无法正常工作

   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);
        }
    });

，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

但是，不建议将Volley library用于大型下载或流式传输操作，但我想分享以下工作示例代码。

我们假设我们只下载 MP3 文件，因此我对扩展程序进行了硬编码。当然，我们应该仔细检查以避免异常（NullPointer ...），例如检查标头是否包含"Content-Disposition"密钥......

希望这有帮助！

排球定制课程：

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);
    }
}

然后在您的活动中：

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：

正如我在下面评论过的，因为直接下载Url会定期更改，所以您应该使用Postman for Chrome之类的工具检查新网址，如果它响应二进制而不是网页（过期的网址），那么网址是有效的，我的代码适用于该网址。

请参阅以下两个屏幕截图：

已过期的网址：

未过期的网址：

更新直接下载链接的基本逻辑来自该网站的文档：

根据Create Your Own YouTube To MP3 Downloader For Free

你可以看看


JSON示例

您还可以通过设置＆＃34;格式＆＃34;来接收JSON中的数据。   参数到＆＃34; JSON＆＃34;。   http://YouTubeInMP3.com/fetch/?format=JSON&video=http://www.youtube.com/watch?v=i62Zjga8JOM

首先，您从上面的文件链接创建一个JsonObjectRequest获取响应。然后，在此onResponse的{{1}}内，您将获得直接下载链接，例如此JsonObjectRequest并使用directUrl = response.getString("link");

我刚刚告诉了获取直接网址的逻辑，IMO，你应该自己实现它。古德勒克！

Answer 2

使用以下代码，它适用于加密网址

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 3

url返回302重定向到实际的.mp3。浏览器会在后台为您重定向，但在您的应用中，您需要自己动手。以下是有关如何使用HttpUrlConnection http://www.mkyong.com/java/java-httpurlconnection-follow-redirect-example/

执行此操作的示例

Answer 4

如果您事先知道文件的类型，那么您可以从没有扩展名的网址下载您的文件。

DownloadService .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");

            }
        }
    }
}

现在通过以下代码启动mainactivity中的服务：

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);

从服务器下载没有扩展名的文件

4 个答案: