How to download a file from a server and save it in specific folder in SD card in Android?

Question

I have one requirement in my Android application. I need to download and save file in specific folder of SD card programmatically. I have developed source code, which is

String DownloadUrl = "http://myexample.com/android/";      String fileName = "myclock_db.db";      DownloadDatabase(DownloadUrl,fileName);      // and the method is  public void DownloadDatabase(String DownloadUrl, String fileName) {     try {         File root = android.os.Environment.getExternalStorageDirectory();         File dir = new File(root.getAbsolutePath() + "/myclock/databases");         if(dir.exists() == false){              dir.mkdirs();           }          URL url = new URL("http://myexample.com/android/");         File file = new File(dir,fileName);          long startTime = System.currentTimeMillis();         Log.d("DownloadManager" , "download url:" +url);         Log.d("DownloadManager" , "download file name:" + fileName);          URLConnection uconn = url.openConnection();         uconn.setReadTimeout(TIMEOUT_CONNECTION);         uconn.setConnectTimeout(TIMEOUT_SOCKET);          InputStream is = uconn.getInputStream();         BufferedInputStream bufferinstream = new BufferedInputStream(is);          ByteArrayBuffer baf = new ByteArrayBuffer(5000);         int current = 0;         while((current = bufferinstream.read()) != -1){             baf.append((byte) current);         }          FileOutputStream fos = new FileOutputStream( file);         fos.write(baf.toByteArray());         fos.flush();         fos.close();         Log.d("DownloadManager" , "download ready in" + ((System.currentTimeMillis() - startTime)/1000) + "sec");         int dotindex = fileName.lastIndexOf('.');         if(dotindex>=0){             fileName = fileName.substring(0,dotindex);      }     catch(IOException e) {         Log.d("DownloadManager" , "Error:" + e);     }  } 

Now the issue is only empty file with filename myclock_db.db is saving in the path. but I need to download and save content of file in the specific folder. Tried several ways to get the file download, but I can't.

Answer 1

Your download URL is not a link to any file. It's a directory. Make sure its a file and exists. Also check your logcat window for error logs. One more suggestion, its always better to do a printStackTrace() in catch blocks instead of Logs. Its gives a more detailed view of the error.

Change this line:

    URL url = new URL("http://myexample.com/android/"); 

to:

    URL url = new URL("http://myexample.com/android/yourfilename.txt"); //some file url 

Next, in catch block, add this line:

e.printStackTrace(); 

Also in the directory path, it should be something like this:

File dir = new File(root.getAbsolutePath() + "/mnt/sdcard/myclock/databases"); 

instead of

File dir = new File(root.getAbsolutePath() + "/myclock/databases"); 

Next, make sure you have acquired permission for writing to external storage in Android manifest.