Develop Reference

Android: Download Manager Request to Cache directory

I need to save sensitive files to a cached directory using the native Download Manager. A location that can not be discovered by the user. I can easily download to the user's external file system using DownloadManager.Request(). Although using setDestinationInExternalPublicDir(), or any other way to set destination, does not allow me to save to a cached directory. Am I missing something here?

The build in DownloadManager can not save files to internal directories. Only to external directories like the SD card and other public directories e.g. the video or photos folder.

You have to forget the Android build in Download manager and create your own manager. Then you can download to path: getCacheDir().getAbsolutePath();
Here is a sample code to download a file yourself without build-in manager
public String downloadFile(String fileURL, String fileName) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
Log.d(TAG, "Downloading...");
try {
int lastDotPosition = fileName.lastIndexOf('/');
if( lastDotPosition > 0 ) {
String folder = fileName.substring(0, lastDotPosition);
File fDir = new File(folder);
fDir.mkdirs();
}
//Log.i(TAG, "URL: " + fileURL);
//Log.i(TAG, "File: " + fileName);
URL u = new URL(fileURL);
HttpURLConnection c = (HttpURLConnection) u.openConnection();
c.setRequestMethod("GET");
c.setReadTimeout(30000);
c.connect();
double fileSize = (double) c.getContentLength();
int counter = 0;
while ( (fileSize == -1) && (counter <=30)){
c.disconnect();
u = new URL(fileURL);
c = (HttpURLConnection) u.openConnection();
c.setRequestMethod("GET");
c.setReadTimeout(30000);
c.connect();
fileSize = (double) c.getContentLength();
counter++;
}
File fOutput = new File(fileName);
if (fOutput.exists())
fOutput.delete();
BufferedOutputStream f = new BufferedOutputStream(new FileOutputStream(fOutput));
InputStream in = c.getInputStream();
byte[] buffer = new byte[8192];
int len1 = 0;
int downloadedData = 0;
while ((len1 = in.read(buffer)) > 0) {
downloadedData += len1;
f.write(buffer, 0, len1);
}
Log.d(TAG, "Finished");
f.close();
return fileName;
}
catch (Exception e) {
e.printStackTrace();
Log.e(TAG, e.toString());
return null;
}
}

How to download and automatic install apk from url in android

I'm trying to programmatically download an .apk file from a given URL and then install it, but I am getting a FileNotFoundException. What could be a possible reason for the issue?
try {
URL url = new URL(fileURL);
HttpURLConnection c = (HttpURLConnection) url.openConnection();
c.setRequestMethod("GET");
c.setDoOutput(true);
c.connect();
String PATH = "/mnt/sdcard/Download/";
File file = new File(PATH);
file.mkdirs();
File outputFile = new File(file, "VersionUpdate.apk");
if(outputFile.exists()){
outputFile.delete();
}
FileOutputStream fos = new FileOutputStream(outputFile);
**//Getting error in this line**
InputStream is = c.getInputStream();
byte[] buffer = new byte[1024];
int len1 = 0;
while ((len1 = is.read(buffer)) != -1) {
fos.write(buffer, 0, len1);
}
fos.flush();
fos.close();
is.close();
} catch (Exception e) {
Log.e("UpdateAPP", "Update error! " + e.getMessage());
}
return null;
}
#Override
protected void onPostExecute(String unused) {
//dismiss the dialog after the file was downloaded
dismissDialog(DIALOG_DOWNLOAD_PROGRESS);
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.setDataAndType(Uri.parse("file:///sdcard/download/VersionUpdate.apk"),"application/vnd.android.package-archive");
startActivity(intent);
}

You just replaced by InputStream is = c.getInputStream(); to given code.
InputStream is ;
int status = c.getResponseCode();
if (status != HttpURLConnection.HTTP_OK)
is = c.getErrorStream();
else
is = c.getInputStream();

Try the following code
File outputFile = new File(file, "VersionUpdate.apk");
if(!outputFile.exists())
{
outputFile.createNewFile();
}
What you are doing is deleting the file, when it already exist, then FileOutputStream will not get file where you want to download the apk .
If the file already exist, FileOutputStream will override the content with new update.
If you have queries, do ask!!

android file download from Internet gives an exception

I am trying to download file form Internet. I have given all permission.But my apps gives some Exception. Here is my source code ..........
private void write()
{
try {
URL url = new URL("http://wordpress.org/plugins/about/readme.txt");
// URL url = new URL("http://androidsaveitem.appspot.com/downloadjpg");
HttpURLConnection c = (HttpURLConnection) url.openConnection();
c.setRequestMethod("GET");
// c.setReadTimeout(10000); // millis
// c.setConnectTimeout(15000); // millis
c.setDoOutput(true);
c.connect();
String PATH = Environment.getExternalStorageDirectory()
+ "/download/";
File file = new File(PATH);
file.mkdirs();
String fileName = "Sap.txt";
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();
// }
} catch (IOException e) {
MessageBox(e.getMessage());
}
}
//permission
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.READ_PHONE_STATE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
c.connect(); // this connect() function gives an exception. I can't identify the problem.
Please somebody help me....

add this in main function
new AsyncTaskRunner().execute("");
add below after main function
private class AsyncTaskRunner extends AsyncTask<String, String, String>
{
#Override
protected void onPostExecute(String result) {
try
{
MessageBox(result);
/*
String PATH = Environment.getExternalStorageDirectory()
+ "/download/";
File file = new File(PATH);
file.mkdirs();
String fileName = "Sap.txt";
File outputFile = new File(file, fileName);
FileOutputStream fos = new FileOutputStream(outputFile);
InputStream is = c;
byte[] buffer = new byte[1024];
int len1 = 0;
while ((len1 = is.read(buffer)) != -1) {
fos.write(buffer, 0, len1);
}
fos.close();
is.close();
*/
}
catch(Exception ex)
{
MessageBox(ex.getMessage()+"error ");
}
}
#Override
protected String doInBackground(String... params) {
try
{
URL url = new URL("http://wordpress.org/plugins/about/readme.txt");
// URL url = new
// URL("http://androidsaveitem.appspot.com/downloadjpg");
HttpURLConnection c = (HttpURLConnection) url.openConnection();
c.setRequestMethod("GET");
// c.setReadTimeout(10000); // millis
// c.setConnectTimeout(15000); // millis
//c.setDoOutput(true);
c.connect();
InputStream is = c.getInputStream();
String PATH = Environment.getExternalStorageDirectory()
+ "/download/";
File file = new File(PATH);
file.mkdirs();
String fileName = "Sap.txt";
File outputFile = new File(file, fileName);
FileOutputStream fos = new FileOutputStream(outputFile);
//InputStream is = c;
byte[] buffer = new byte[1024];
int len1 = 0;
while ((len1 = is.read(buffer)) != -1) {
fos.write(buffer, 0, len1);
}
fos.close();
is.close();
Log.v("esty", "Successfully");
return "Successfully";
}
catch(Exception ex)
{
Log.v("esty", ex.getMessage());
return "failed"+ex.getMessage();
}
}
i hope it solves your problem! :)

Save image from url to sdcard

I am saving image from url to sdcard. But image size is 0 in sdcard. Image is created in sdcard but now retrieve data from url and save. so it is giving me 0 size.
try
{
URL url = new URL("http://api.androidhive.info/images/sample.jpg");
InputStream input = url.openStream();
try {
//The sdcard directory e.g. '/sdcard' can be used directly, or
//more safely abstracted with getExternalStorageDirectory()
File storagePath = Environment.getExternalStorageDirectory();
OutputStream output = new FileOutputStream (new File(storagePath,username+".png"));
try {
byte[] buffer = new byte[2048];
int bytesRead = 0;
while ((bytesRead = input.read(buffer, 0, buffer.length)) >= 0) {
output.write(buffer, 0, bytesRead);
}
} finally {
output.close();
}
} finally {
input.close();
}
} catch(Exception e)
{
System.out.println("error in sd card "+e.toString());
}

Try this code.It works...
You should have permission of internet and write external storage.
try
{
URL url = new URL("Enter the URL to be downloaded");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
urlConnection.connect();
File SDCardRoot = Environment.getExternalStorageDirectory().getAbsoluteFile();
String filename="downloadedFile.png";
Log.i("Local filename:",""+filename);
File file = new File(SDCardRoot,filename);
if(file.createNewFile())
{
file.createNewFile();
}
FileOutputStream fileOutput = new FileOutputStream(file);
InputStream inputStream = urlConnection.getInputStream();
int totalSize = urlConnection.getContentLength();
int downloadedSize = 0;
byte[] buffer = new byte[1024];
int bufferLength = 0;
while ( (bufferLength = inputStream.read(buffer)) > 0 )
{
fileOutput.write(buffer, 0, bufferLength);
downloadedSize += bufferLength;
Log.i("Progress:","downloadedSize:"+downloadedSize+"totalSize:"+ totalSize) ;
}
fileOutput.close();
if(downloadedSize==totalSize) filepath=file.getPath();
}
catch (MalformedURLException e)
{
e.printStackTrace();
}
catch (IOException e)
{
filepath=null;
e.printStackTrace();
}
Log.i("filepath:"," "+filepath) ;
return filepath;

Try this, this may late but it will help someone.
private class ImageDownloadAndSave extends AsyncTask<String, Void, Bitmap>
{
#Override
protected Bitmap doInBackground(String... arg0)
{
downloadImagesToSdCard("","");
return null;
}
private void downloadImagesToSdCard(String downloadUrl,String imageName)
{
try
{
URL url = new URL(img_URL);
/* making a directory in sdcard */
String sdCard=Environment.getExternalStorageDirectory().toString();
File myDir = new File(sdCard,"test.jpg");
/* if specified not exist create new */
if(!myDir.exists())
{
myDir.mkdir();
Log.v("", "inside mkdir");
}
/* checks the file and if it already exist delete */
String fname = imageName;
File file = new File (myDir, fname);
if (file.exists ())
file.delete ();
/* Open a connection */
URLConnection ucon = url.openConnection();
InputStream inputStream = null;
HttpURLConnection httpConn = (HttpURLConnection)ucon;
httpConn.setRequestMethod("GET");
httpConn.connect();
if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK)
{
inputStream = httpConn.getInputStream();
}
FileOutputStream fos = new FileOutputStream(file);
int totalSize = httpConn.getContentLength();
int downloadedSize = 0;
byte[] buffer = new byte[1024];
int bufferLength = 0;
while ( (bufferLength = inputStream.read(buffer)) >0 )
{
fos.write(buffer, 0, bufferLength);
downloadedSize += bufferLength;
Log.i("Progress:","downloadedSize:"+downloadedSize+"totalSize:"+ totalSize) ;
}
fos.close();
Log.d("test", "Image Saved in sdcard..");
}
catch(IOException io)
{
io.printStackTrace();
}
catch(Exception e)
{
e.printStackTrace();
}
}
}
Declare your network operations in AsyncTask as it will load it as a background task. Don't load network operation on main thread. After this either in button click or in content view call this class like
new ImageDownloadAndSave().execute("");
And don't forget to add the nework permission as:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.INTERNET" />
Hope this will help :-)

Convert a BufferedInputStream to a File

I am loading a image from the web to the local android phone. The code that I have for writing to a file is as follows
BufferedInputStream bisMBImage=null;
InputStream isImage = null;
URL urlImage = null;
URLConnection urlImageCon = null;
try
{
urlImage = new URL(imageURL); //you can write here any link
urlImageCon = urlImage.openConnection();
isImage = urlImageCon.getInputStream();
bisMBImage = new BufferedInputStream(isImage);
int dotPos = imageURL.lastIndexOf(".");
if (dotPos > 0 )
{
imageExt = imageURL.substring(dotPos,imageURL.length());
}
imageFileName = PATH + "t1" + imageExt;
File file = new File(imageFileName);
if (file.exists())
{
file.delete();
Log.d("FD",imageFileName + " deleted");
}
ByteArrayBuffer baf = new ByteArrayBuffer(255);
Log.d("IMAGEWRITE", "Start to write image to Disk");
int current = 0;
try
{
while ((current = bisMBImage.read()) != -1)
{
baf.append((byte) current);
}
FileOutputStream fos = new FileOutputStream(file);
fos.write(baf.toByteArray());
fos.close();
Log.d("IMAGEWRITE", "Image write to Disk done");
}
catch (IOException e)
{
e.printStackTrace();
}
isImage.close();
}
catch (IOException e)
{
Log.d("DownloadImage", "Error: " + e);
}
finally
{
isImage = null;
urlImageCon = null;
urlImage = null;
}
For some reason the whole writing to a file takes 1 minute. Is there a way I can optimize this ?

Your buffer is very small: 255 bytes. You could make it 1024 times bigger (255 kilobytes). This is an acceptable size and this would certainly speed up the thing.
Also, this is very slow as it reads the bytes one by one:
while ((current = bisMBImage.read()) != -1) {
baf.append((byte) current);
}
You should try using the array version of read() instead: read(byte[] buffer, int offset, int byteCount) with an array as large as what I have described above.

You should use the Android HttpClient for file fetching over the java URL Connection. Also your Buffer is very small.
Try this snipped:
FileOutputStream f = new FileOutputStream(new File(root,"yourfile.dat"));
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet request = new HttpGet(urlString);
HttpResponse response = httpClient.execute(request);
InputStream is = response.getEntity().getContent();
byte[] buffer = new byte[1024];
int len1 = 0;
while ( (len1 = is.read(buffer)) > 0 ) {
f.write(buffer,0, len1);
}
f.close();