Develop Reference

How to programatically download files with increased speed in android

Hi have implemented programatically downloading of file using inputstream and cipheroutputstream(for encryption). The download is happening very slow. Whereas if i try to download via download manager, it is very fast. What can i do to improve my code and increase the download speed of the file. Below is my code.
private void saveFileUsingEncryption(String aMineType, long length) throws Exception {
int bufferSize = 1024*4;
//byte[] buffer = new byte[1024];
byte[] buffer = new byte[bufferSize];
int bytesRead = 0;
long totalRead = 0;
FileOutputStream outStream = null;
File f = new File(Constants.DWLPATH);
if (!f.exists()) {
f.mkdirs();
}
try {
Cipher aes = Cipher.getInstance("ARC4");
aes.init(Cipher.ENCRYPT_MODE, new SecretKeySpec("mykey".getBytes(), "ARC4"));
if(contDisp==null || contDisp.length()==0) {
// downloadFileName = downloadFileName.replaceAll("[^a-zA-Z0-9_]+", "");
downloadFileName = downloadFileName + "." + getFileExtension(aMineType);
}
outStream = new FileOutputStream(Constants.DWLPATH + downloadFileName,true);
CipherOutputStream out = new CipherOutputStream(outStream, aes);
while ((bytesRead = inputStream.read(buffer, 0, bufferSize)) >= 0) {
out.write(buffer, 0, bytesRead);
try{
// Adjust this value. It shouldn't be too small.
Thread.sleep(50);
}catch (InterruptedException e){
TraceUtils.logException(e);
}
totalRead += bytesRead;
sb=sb.append("\n Total bytes Read:"+totalRead);
Log.e("--",sb.toString());
/* if (this.length > 0) {
Long[] progress = new Long[5];
progress[0] = (long) ((double) totalRead / (double) this.length * 100.0);
publishProgress(progress);
}*/
if (this.isCancelled()) {
if (conn != null)
conn.disconnect();
conn = null;
break;
}
}
Log.e("Download completed","success");
out.flush();
//Utils.putDownloadLogs(requestUrl,mimeType,length, downloadFileName,"Download is Successful",sb.toString(), context);
outStream.close();
buffer = null;
} catch (Exception e) {
TraceUtils.logException( e);
file_newsize = storedFileSizeInDB + totalRead;
if (totalFileSize == 0)
totalFileSize = length;
callback.onRequestInterrupted(file_newsize,totalFileSize);
StringWriter errors = new StringWriter();
e.printStackTrace(new PrintWriter(errors));
// Utils.putDownloadLogs(requestUrl,mimeType,length,downloadFileName,"failure---" + errors.toString(),sb.toString(), context);
throw e;
} finally {
if (outStream != null)
outStream.close();
outStream = null;
}
}

You can use default download manager to download the file because its very easy to implement and provide better features like respond to the internet connection , provide accessibility to add notification in status bar , by running the query on download manager object you can find the total bytes and remaining bytes so you can calculate the progress and after completion of download by tapping the notification one can perform the desired operation.
And also there are many libraries are available for to achieve this like
PRDOWNLOADER
FetchDownloader
This libraires provide you the feature of pause,download, resume download , tracking the progress and cancel download
Also you can customize it as per your need.

Here is the DownloadAndEncryptFileTask.class to download with encryption
public class DownloadAndEncryptFileTask extends AsyncTask<Void, Void, Void> {
private String mUrl;
private File mFile;
private Cipher mCipher;
InputStream inputStream;
FileOutputStream fileOutputStream;
CipherOutputStream cipherOutputStream;
public DownloadAndEncryptFileTask(String url, File file, Cipher cipher) {
if (url == null || url.isEmpty()) {
throw new IllegalArgumentException("You need to supply a url to a clear MP4 file to download and encrypt, or modify the code to use a local encrypted mp4");
}
mUrl = url;
mFile = file;
mCipher = cipher;
}
private void downloadAndEncrypt() throws Exception {
URL url = new URL(mUrl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
if (mFile.length() > 0) {
connection.setRequestProperty("Range", "bytes=" + mFile.length() + "-");
}
connection.connect();
Log.e("length", mFile.length() + "");
if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
throw new IOException("server error: " + connection.getResponseCode() + ", " + connection.getResponseMessage());
}
inputStream = connection.getInputStream();
if (mFile.length() > 0) {
//connection.connect();
fileOutputStream = new FileOutputStream(mFile, true);
} else {
fileOutputStream = new FileOutputStream(mFile);
}
CipherOutputStream cipherOutputStream = new CipherOutputStream(fileOutputStream, mCipher);
byte buffer[] = new byte[1024 * 1024];
int bytesRead;
while ((bytesRead = inputStream.read(buffer)) != -1) {
Log.d(getClass().getCanonicalName(), "reading from http...");
cipherOutputStream.write(buffer, 0, bytesRead);
}
inputStream.close();
cipherOutputStream.close();
connection.disconnect();
}
#Override
protected Void doInBackground(Void... params) {
try {
downloadAndEncrypt();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
Log.d(getClass().getCanonicalName(), "done");
}
}
Call this class
new DownloadAndEncryptFileTask(
myFeedsModel.getVideo().getVideo360(),
new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), myFeedsModel.getFile_name()),
OBJECT OF YOUR CIPHER

how to install an app from internal storage files

I'm trying to download an apk file then install it.
I have done it with an external storage directory but when I download the file in a Local directory I can't parse it.
Here is the code on OnCreate method
final DownloadTask downloadTask = new DownloadTask(this);
downloadTask.execute("http://file.appsapk.com/wp-content/uploads/apps-2/Gmail.apk","Gmail.apk");
DownloadTask is a class that extends from AsyncTask.
Here is the background task:
#Override
protected String doInBackground(String... sUrl) {
file_name=sUrl[1];
Boolean isSDPresent = android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);
if (isSDPresent) {
directory = new File(Environment.getExternalStorageDirectory()+File.separator+"app_directory");
}
else
{
directory = getFilesDir();
}
if (!directory.exists())
directory.mkdirs();
InputStream input = null;
OutputStream output = null;
HttpURLConnection connection = null;
try {
URL url = new URL(sUrl[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
return "Server returned HTTP " + connection.getResponseCode()
+ " " + connection.getResponseMessage();
}
int fileLength = connection.getContentLength();
input = connection.getInputStream();
output = new FileOutputStream(directory+"/"+file_name);
byte[] buffer = new byte[1024];
long total = 0;
int count;
while ((count = input.read(buffer)) != -1) {
if (isCancelled()) {
input.close();
return null;
}
total += count;
if (fileLength > 0) // only if total length is known
publishProgress((int) (total * 100 / fileLength));
output.write(buffer, 0, count);
}
} catch (Exception e) {
return e.toString();
} finally {
try {
if (input != null)
input.close();
if (output != null)
output.close();
} catch (IOException ignored) {
}
if (connection != null)
connection.disconnect();
}
return null;
}
And this is the post execution method that runs after the first one done downloading the file:
#Override
protected void onPostExecute(String result) {
mWakeLock.release();
mProgressDialog.dismiss();
if (result != null)
{
Toast.makeText(context,"Download error: "+result, Toast.LENGTH_LONG).show();
}
else
{
Toast.makeText(context, "File downloaded", Toast.LENGTH_SHORT).show();
File file = new File(directory, file_name);
Intent promptInstall = new Intent(Intent.ACTION_VIEW)
.setDataAndType(Uri.fromFile(file),
"application/vnd.android.package-archive");
context.startActivity(promptInstall);
finish();
}
It runs perfectly with an external storage but it won't run with an external one. Why not?

Try to use openfileoutput() rather than OutputStream in saving your file in internal storage and allow it to be readable. http://developer.android.com/guide/topics/data/data-storage.html#filesInternal . The package error is mainly caused by the permission of internal storage.

It's because of android application can not read from another application file if it is written using PRIVATE mode.So you have to change the mode of the file. i have just modify else part of your onPostExecute() method below.
try {
String tempfile="xyzfile";
File file = new File(directory, file_name);
FileInputStream inStream = new FileInputStream(file);
FileOutputStream fos = context.openFileOutput(tempfile,
context.MODE_WORLD_WRITEABLE | context.MODE_WORLD_READABLE);
byte[] buffer = new byte[1024];
int length;
// copy the file content in bytes
while ((length = inStream.read(buffer)) > 0) {
fos.write(buffer, 0, length);
}
inStream.close();
fos.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
File file = new File(context.getFilesDir(), tempfile);
Intent promptInstall = new Intent(Intent.ACTION_VIEW).setDataAndType(
Uri.fromFile(file), "application/vnd.android.package-archive");
context.startActivity(promptInstall);

Download resume not working in setRequestProperty method

This is my doInBackground method:
#Override
protected String doInBackground(String... sUrl) {
InputStream input = null;
HttpURLConnection conection = null;
BufferedOutputStream bout = null;
FileOutputStream fos = null;
int downloaded = 0;
try {
URL url = new URL(sUrl[0]);
conection = (HttpURLConnection)url.openConnection();
int lenghtOfFile = conection.getContentLength();
if(STATUS) {
File file = new File(Environment.getExternalStorageDirectory().getPath() + "/myapp.apk");
if (file.exists()) {
downloaded = (int) file.length();
conection.setRequestProperty("Range", "bytes=" + (file.length()) + "-");
}
}
else {
conection.setRequestProperty("Range", "bytes=" + downloaded + "-");
}
conection.setDoInput(true);
conection.setDoOutput(true);
conection.connect();
input = new BufferedInputStream(url.openStream(), 8192);
fos=(downloaded==0)? new FileOutputStream(Environment.getExternalStorageDirectory().getPath() + "/myapp.apk"): new FileOutputStream(Environment.getExternalStorageDirectory().getPath() + "/myapp.apk",true);
bout = new BufferedOutputStream(fos, 1024);
byte data[] = new byte[1024];
long total = 0;
int count = 0;
while ((count = input.read(data, 0, 1024)) >= 0) {
if (isCancelled()) {
input.close();
return null;
}
bout.write(data, 0, count);
downloaded += count;
publishProgress((int)(downloaded * 100/ lenghtOfFile) );
total += count;
}
bout.flush();
input.close();
fos.close();
} catch (Exception e) {
Log.e("Error: ", e.getMessage());
} finally {
try {
if (output != null)
output.close();
if (input != null)
input.close();
if (fos != null)
fos.close();
if (bout != null)
bout.close();
} catch (IOException ignored) {
}
if (conection != null)
conection = null;
}
return null;
}
I start download task with this code (resume flag is false -> STATUS = FALSE):
dt = new DownloadTask(DownloadsActivity.this, false);
dt.execute("myurl.something.apk");
then when downloaded completely I launch apk file and all thing work correctly and apk installed correctly. But when pause my download with this code:
dt.cancel(true);
and then resume it with this code (resume flag is true-> STATUS = TRUE):
dt = new DownloadTask(DownloadsActivity.this, true);
dt.execute("myurl.something.apk");
This time apk size is equal to last downloaded before pause + apk total size, therefore my apk file is corrupted. Which means connection.setRequestProperty() not working for me. What is my code problem? Thanks in advance.

Android download even if does not exist

try {
URL url = new URL("http://URL/Dragonfly.db");
HttpURLConnection c = (HttpURLConnection) url.openConnection();
c.setRequestMethod("GET");
c.setDoOutput(true);
c.connect();
String[] path = url.getPath().split("/");
String _file = path[path.length - 1];
int lengthOfFile = c.getContentLength();
if(lengthOfFile > 0){ // Copy file if Length > 0
String PATH = db.DB_PATH; ;//Environment.getExternalStorageDirectory()+
Log.v("", "PATH: " + PATH);
File file = new File(PATH);
file.mkdirs();
String fileName = "Dragonfly.db";
File outputFile = new File(file , fileName);
FileOutputStream fos = new FileOutputStream(outputFile);
InputStream is = c.getInputStream();
byte[] buffer = new byte[1024];
int len1 = 0;
while ((len1 = is.read(buffer)) != -1) {
fos.write(buffer, 0, len1);
}
fos.close();
is.close();
}else{
TestAdapter mDbHelper = new TestAdapter(getBaseContext());
mDbHelper.createDatabase();
}
} catch (IOException e) {
e.printStackTrace();
}
I use this code to update database, downloading a new one. but if i dont have a file on server, it replace the database i have for a new empty one (0bytes).
How can i download the file just if it exist on server?

Try to do a status response check:
int responseCode = c.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
{
// update database replacing the old one with the new one
} else {
// continue to use old database
}

Resume Download not working in android

This code for resuming download is not working properly in Android, although it works fine in a Java application. Here I am trying to download a zip file, and it will resume the download, but the net result is an invalid zip file.
BufferedInputStream in = null;
FileOutputStream fos = null;
BufferedOutputStream bout=null;
try {
downloaded=0;
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
if(ISSUE_DOWNLOAD_STATUS.intValue()==ECMConstant.ECM_DOWNLOADING){
File file=new File(DESTINATION_PATH);
if(file.exists()){
downloaded = (int) file.length();
}
}
connection.setRequestProperty("Range", "bytes=" + downloaded + "-");
connection.connect();
size=connection.getContentLength();
Dialog.setMax(size);
in = new BufferedInputStream(connection.getInputStream());
fos=(downloaded==0)? new FileOutputStream(DESTINATION_PATH): new FileOutputStream(DESTINATION_PATH,true);
bout = new BufferedOutputStream(fos, 1024);
byte[] data = new byte[1024];
int x = 0;
while ((x = in.read(data, 0, 1024)) >= 0) {
bout.write(data, 0, x);
downloaded += x;
System.out.println(downloaded);
onProgressUpdate((int)(downloaded*100/size));
}
succes=true;
} catch (Exception e) {
e.printStackTrace();
} finally {
try {
in.close();
bout.close();
} catch (IOException e) {
e.printStackTrace();
}
}
Thanks.

HttpURLConnection connection = (HttpURLConnection) url.openConnection();
int buf = 1024;
if (ISSUE_DOWNLOAD_STATUS.intValue() == ECMConstant.ECM_DOWNLOADING) {
File file = new File(DESTINATION_PATH);
if (file.exists()) {
downloaded = (int) file.length();
connection.setRequestProperty("Range",
"bytes=" + file.length() + "-");
}
} else {
connection.setRequestProperty("Range", "bytes=" + downloaded + "-");
}
connection.setDoInput(true);
connection.setDoOutput(true);
progressBar.setMax(connection.getContentLength());
in = new BufferedInputStream(connection.getInputStream());
fos = new FileOutputStream(DESTINATION_PATH, downloaded == 0 ? false : true);
bout = new BufferedOutputStream(fos, buf);
byte[] data = new byte[buf];
while ((int x = in.read(data, 0, buf)) >= 0) {
bout.write(data, 0, x);
downloaded += x;
progressBar.setProgress(downloaded);
}

Your zip file is corrupted because you think that the stream resumes from the range byte that you specified. It actually streams from the beginning again, and so you have a file bigger than the original. Long story short, your server does not support the range property.