I've got a question that probably borders on opinion, but I've not any related questions or documentation that answers, so I feel like it's a fair one to ask.
I'm trying to build an android app which modifies music files, and what I'd like to do is have a shared folder so that the files and the results can be accessible and shared. I'd like it if it was among the other folders like Music, Downloads, Movies, etc, or even under Music since it's music related. However this seems like it's a security no no in Android, as after I've made something and put it in there I have to use an intent to access it again, where as I'd rather just be able to open the files and not have a permissions based fiasco. Maybe some type of symbolic link like in Linux that pointed to my apps internal folder could be used, but of this I'm still uncertain.
In any case, is there a way I should go about this? If so, are there some resources I could be pointed to?
Thank you in advance to anyone who takes this up!
Edit for CommonsWare:
I used the following to create the folder:
File mediaStorageDir = new File(Environment.getExternalStorageDirectory(), APP_NAME);
And this to copy files from elsewhere to there:
public void copyFileToHomeDirectory(Uri uri)
{
try
{
ContentResolver contentResolver = getApplicationContext().getContentResolver();
String fileName = queryName(contentResolver, uri);
//Get file extension
String fileType = fileName.substring(fileName.length() - 4, fileName.length());
if(fileType.equalsIgnoreCase(MP3_EXTENSION))
{
String path = Environment.getExternalStorageDirectory() + APP_FOLDER;
InputStream in = contentResolver.openInputStream(uri);
File outputFile = new File(path + File.separator + fileName);
outputFile.createNewFile();
OutputStream out = new FileOutputStream(outputFile);
//First we crack open the file to copy it's contents:
byte[] buffer = new byte[KB_SIZE];
int read;
while ((read = in.read(buffer)) != -1)
{
out.write(buffer, 0, read);
}
in.close();
in = null;
// write the output file (You have now copied the file)
out.flush();
out.close();
out = null;
}
}
catch(FileNotFoundException fnfe)
{
Log.e(TAG, "FileNotFoundException");
Log.e(TAG, Log.getStackTraceString(fnfe));
}
catch(IOException ioe)
{
Log.e(TAG, "IOException");
Log.e(TAG, Log.getStackTraceString(ioe));
}
catch(Exception e)
{
Log.e(TAG, "General Exception");
Log.e(TAG, Log.getStackTraceString(e));
}
}
I've tried other methods that I've overwritten in the process, but accessing the files to be used again I need something like this:
public void openDirectory(View view)
{
// Choose a directory using the system's file picker.
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
// Provide read access to files and sub-directories in the user-selected
// directory.
//intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
//intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
//intent.addCategory(Intent.CATEGORY_OPENABLE);
// Optionally, specify a URI for the directory that should be opened in
// the system file picker when it loads.
//intent.putExtra(DocumentsContract.EXTRA_INITIAL_URI, uriToLoad);
intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("*/*"); //use image/* for photos, etc.
//The result of this code will be calling the onActivityResult function below
startActivityForResult(intent, REQUEST_MUSIC_DIR);
}
Edit2:
I've reorganized the folders to what I think I should be doing so that I can work with the files freely, however, even in my internal cache storage (getCacheDir() + folder_name) either isn't letting me create the files (outputFile.createNewFile doesn't throw an error) or it isn't letting me open them when I go to get a directory listing.
Here's my code for creating the file:
String path = getCacheDir() + MY_SUB_FOLDER;
//uri is obtained through ACTION_OPEN_DOCUMENT intent
InputStream in = contentResolver.openInputStream(uri);
File outputFile = new File(path + "/" + fileName);
outputFile.createNewFile();
Log.i(TAG, "The new file's directory/path is: " + outputFile.getAbsolutePath());
//NOTE: This is returning /data/user/0/com.example.myapplication/cache/MY_SUB_FOLDER/file_name.mp3
OutputStream out = new FileOutputStream(outputFile);
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1)
{
out.write(buffer, 0, read);
}
in.close();
in = null;
out.flush();
out.close();
out = null;
This is my code for attempting to open and read these newly created files
File directory = new File(getCacheDir(), MY_SUB_FOLDER);
Log.i(TAG, "This is the directory we're trying to get the files from: " + directory.getAbsolutePath());
//NOTE: This returns /data/user/0/com.example.myapplication/cache/MY_SUB_FOLDER
File[] files = directory.listFiles();
if(files != null)
{
for(int i = 0; i < files.length; i++)
{
Log.d(TAG, "Files found: " + files[i].getAbsolutePath());
}
}
The files variable isn't null but it's length is 0 and no files are found.
Edit3:
I am catching the exceptions and logging any stack traces, which currently returns nothing.
catch(FileNotFoundException fnfe)
{
Log.i(TAG, "FileNotFoundException");
Log.i(TAG, Log.getStackTraceString(fnfe));
}
catch(IOException ioe)
{
Log.i(TAG, "IOException");
Log.i(TAG, Log.getStackTraceString(ioe));
}
catch(Exception e)
{
Log.i(TAG, "General Exception");
Log.i(TAG, Log.getStackTraceString(e));
}
Related
Trying to use the following code to copy a file from one directory to another and rename
String Path3= "/storage/extSDCard/DCIM/Camera/fred.jpg";
File to = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "Barr.jpg");
File oldFile = new File (Path3);
oldFile.renameTo(to);
It doesn't appear to copy the file. in this case the path Path3 is on the SDCard but I also need it to copy from one directory to another on the device as well
Basically I'm using the gallery picker to pick an image from somewhere I convert the uri to a path I then need to copy the file from where it is stored to the pictures directory and rename it
Any idea where I'm going wrong?
I solved it from A variety of sources was going about it in the wrong way. This Code Works:
File sourceLocation = new File (Path2);
File targetLocation = new File (Path3 + "/" + imageFileName);
Log.v(TAG, "sourceLocation: " + sourceLocation);
Log.v(TAG, "targetLocation: " + targetLocation);
try {
int actionChoice = 2;
if(actionChoice==1){
if(sourceLocation.renameTo(targetLocation)){
Log.v(TAG, "Move file successful.");
}else{
Log.v(TAG, "Move file failed.");
}
}
else{
if(sourceLocation.exists()){
InputStream in = new FileInputStream(sourceLocation);
OutputStream out = new FileOutputStream(targetLocation);
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
in.close();
out.close();
Log.v(TAG, "Copy file successful.");
}else{
Log.v(TAG, "Copy file failed. Source file missing.");
}
}
} catch (NullPointerException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
I am making a soundboard for practice and I want to give the user the ability to download the sound (that I have included in the app in the res/raw folder) onClick of a menu item but I can only find information about downloading from an internet url, not something that I already included in the apk.
What is the best way to do this? I would like to give them the option to save to an SD card also if this is possible. A point towards the correct class to use in the documentation would be great! I've been googling to no avail.
Thanks!
Try something like this:
public void saveResourceToFile() {
InputStream in = null;
FileOutputStream fout = null;
try {
in = getResources().openRawResource(R.raw.test);
String downloadsDirectoryPath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS).getAbsolutePath();
String filename = "myfile.mp3"
fout = new FileOutputStream(new File(downloadsDirectoryPath + filename));
final byte data[] = new byte[1024];
int count;
while ((count = in.read(data, 0, 1024)) != -1) {
fout.write(data, 0, count);
}
} finally {
if (in != null) {
in.close();
}
if (fout != null) {
fout.close();
}
}
}
I don't know about the raw but I did a similar thing in my app using the assets folder. My files are under the assets/backgrounds folder as you can probably guess from the code below.
You can modify this code and make it work for you (I know I will only have 4 files which is why I have i go from 0 to 4 but you can change this to whatever you want).
This code copies the file starting with prefix_ (like prefix_1.png, prefix_2.png, etc) to my cache directory but you can obviously change the extension, the filename or the path you would like to save the assets to.
public static void copyAssets(final Context context, final String prefix) {
for (Integer i = 0; i < 4; i++) {
String filename = prefix + "_" + i.toString() + ".png";
File f = new File(context.getCacheDir() + "/" + filename);
if (f.exists()) {
f.delete();
}
if (!f.exists())
try {
InputStream is = context.getAssets().open("backgrounds/" + filename);
int size = is.available();
byte[] buffer = new byte[size];
is.read(buffer);
is.close();
FileOutputStream fos = new FileOutputStream(f);
fos.write(buffer);
fos.close();
} catch (Exception e) {
Log.e("Exception occurred while trying to load file from assets.", e.getMessage());
}
}
}
I am using following code to download and read a PDF file from internal storage on device.
I am able to download the files successfully to the directory:
data/data/packagename/app_books/file.pdf
But I am unable to read the file using a PDF reader application like Adobe Reader.
Code to download file
//Creating an internal dir;
File mydir = getApplicationContext().getDir("books", Context.MODE_WORLD_READABLE);
try {
File file = new File(mydir, outputFileName);
URL downloadUrl = new URL(url);
URLConnection ucon = downloadUrl.openConnection();
ucon.connect();
InputStream is = ucon.getInputStream();
FileOutputStream fos = new FileOutputStream(file);
byte data[] = new byte[1024];
int current = 0;
while ((current = is.read(data)) != -1) {
fos.write(data, 0, current);
}
is.close();
fos.flush();
fos.close();
isFileDownloaded=true;
} catch (IOException e) {
e.printStackTrace();
isFileDownloaded = false;
System.out.println(outputFileName + " not downloaded");
}
if (isFileDownloaded)
System.out.println(outputFileName + " downloaded");
return isFileDownloaded;
Code to read the file
PackageManager packageManager = getPackageManager();
Intent testIntent = new Intent(Intent.ACTION_VIEW);
testIntent.setType("application/pdf");
List list = packageManager.queryIntentActivities(testIntent,
PackageManager.MATCH_DEFAULT_ONLY);
try {
Intent intent = new Intent();
intent.setAction(Intent.ACTION_VIEW);
File fileToRead = new File(
"/data/data/com.example.filedownloader/app_books/Book.pdf");
Uri uri = Uri.fromFile(fileToRead.getAbsoluteFile());
intent.setDataAndType(uri, "application/pdf");
startActivity(intent);
} catch (Exception ex) {
Log.i(getClass().toString(), ex.toString());
Toast.makeText(MainActivity.this,
"Cannot open your selected file, try again later",
Toast.LENGTH_SHORT).show();
}
All works fine but the reader app says "File Path is not valid".
Your path is only valid for your app. Place the file in a place where other apps can 'see' it. Use GetExternalFilesDir() or getExternalStorageDirectory().
Note about files which are created inside the directory created by Context.getDir(String name, int mode) that they will only be accessible by your own application; you can only set the mode of the entire directory, not of individual files.
So you can use Context.openFileOutput(String name, int mode). I'm re-using your code for an example:
try {
// Now we use Context.MODE_WORLD_READABLE for this file
FileOutputStream fos = openFileOutput(outputFileName,
Context.MODE_WORLD_READABLE);
// Download data and store it to `fos`
// ...
You might want to take a look at this guide: Using the Internal Storage.
If you would like to keep the file app specific, you can use PdfRenderer available for Lollipop and above builds. There are great tutorials on google and youtube that work well. The method you are using is a secure way to store a PDF file that is only readable from inside the app ONLY. No outside application like Adobe PDF Reader will be able to even see the file.It took me a lot of seaching but I found a solution to my specific usage by using this site and especially youtube.
How to download PDF file from asset folder to storage by making folder
make sure you have storage permission are given like marshmallow device support etc then follow these steps
private void CopyReadAssets()
{
AssetManager assetManager = getContext().getAssets();
FileInputStream in = null;
FileOutputStream out = null;
File sdcard = Environment.getExternalStorageDirectory();
File dir = new File(Environment.getExternalStorageDirectory()+File.separator+ "A_level");
File dir2;
if (dir.exists() && dir.isDirectory()){
Log.e("tag out", ""+ dir);
}else {
dir.mkdir();
Log.e("tag out", "not exist");
}
File file = new File(dir, mTitle+".pdf");
try
{
Log.e("tag out", ""+ file);
out = new FileOutputStream(file);
in = new FileInputStream (new File(mPath));
Log.e("tag In", ""+ in);
copyFile(in, out);
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch (Exception e)
{
Log.e("tag out", ""+ out);
Log.e("tag In", ""+ in);
Log.e("tag", e.getMessage());
Log.e("tag", ""+file);
Log.i("tag",""+sdcard.getAbsolutePath() + "A_level");
}
}
private void copyFile(InputStream in, OutputStream out) throws IOException
{
byte[] buffer = new byte[1024];
int read;
while ((read = in.read(buffer)) != -1)
{
out.write(buffer, 0, read);
}
}
I have an interesting problem: My application is designed to send and open up a zip full of files, and the zip has a special extension (easier for the user). I can zip up the files I need to attach in an e-mail, and I can send them.
When I use the g-mail "view" button and select my app to open the file, it doesn't unzip them correctly. However, if I use the gmail "download" button, and then open the file through a file explorer, the file unzips correctly.
This is the code I use to download the attachment:
// get attachment
try {
attachment = getContentResolver().openInputStream(
getIntent().getData());
} catch (FileNotFoundException e) {
e.printStackTrace();
}
// Save it
try {
File root = Environment.getExternalStorageDirectory();
path = root.getPath() + "/PSattachment.psz";
savedFile = new File(path);
FileOutputStream fos = new FileOutputStream(savedFile, false);
BufferedOutputStream os = new BufferedOutputStream(fos);
byte[] buffer = new byte[1024];
int byteRead = 0;
while ((byteRead = attachment.read(buffer)) != -1) {
os.write(buffer, 0, byteRead);
}
fos.close();
} catch (Exception e) {
e.printStackTrace();
}
Am I doing something wrong? Thanks in advance. (Also, the process of unzipping is the same in both cases [file explorer and view from email], so I'm pretty sure it's something in here. Also, the file DOES download, and is the right size. It just won't unzip).
I found the answer!!! Took a while, but at least it works now:
try {
InputStream attachment = getContentResolver()
.openInputStream(getIntent().getData());
savedFile = new File(Environment
.getExternalStorageDirectory().getAbsolutePath(),
"temp" + System.currentTimeMillis() + ".psz");
FileOutputStream f = new FileOutputStream(savedFile);
byte[] buffer = new byte[1024];
int len1 = 0;
while ((len1 = attachment.read(buffer)) > 0) {
f.write(buffer);
}
f.close();
} catch (Exception e) {
}
I just used this code to download the attachment and now everything works perfectly =D
Check this out please:
http://www.jondev.net/articles/Unzipping_Files_with_Android_(Programmatically)
A guide to unzip files in android, hope it helps solve your problem
I am trying to create a folder and several subdirectory within it on the SD Card... I then want to transfer files that I have stored in /res/raw to that folder... I addition, I want this to only happen once, the first time the program is ever run. I realize that this is ridiculously open-ended, and that I am asking a lot... but any help would be greatly appreciated.
This will copy all files in the "clipart" subfolder of the .apk assets folder to the "clipart" subfolder of your app's folder on the SD card:
String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
String basepath = extStorageDirectory + "/name of your app folder on the SD card";
//...
// in onCreate
File clipartdir = new File(basepath + "/clipart/");
if (!clipartdir.exists()) {
clipartdir.mkdirs();
copyClipart();
}
private void copyClipart() {
AssetManager assetManager = getResources().getAssets();
String[] files = null;
try {
files = assetManager.list("clipart");
} catch (Exception e) {
Log.e("read clipart ERROR", e.toString());
e.printStackTrace();
}
for(int i=0; i<files.length; i++) {
InputStream in = null;
OutputStream out = null;
try {
in = assetManager.open("clipart/" + files[i]);
out = new FileOutputStream(basepath + "/clipart/" + files[i]);
copyFile(in, out);
in.close();
in = null;
out.flush();
out.close();
out = null;
} catch(Exception e) {
Log.e("copy clipart ERROR", e.toString());
e.printStackTrace();
}
}
}
private void copyFile(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int read;
while((read = in.read(buffer)) != -1){
out.write(buffer, 0, read);
}
}
I experienced a similar problem when using mkdirs(), however because running the command:
mkdir one/two
fails on Linux, then the method http://download.oracle.com/javase/1.4.2/docs/api/java/io/File.html#mkdirs() subsequently fails too. I guess this means there is no way to use mkdirs on Android? My (probably rather hacky) work-around was to create each necessary directory separately:
String extStorageDirectory = Environment.getExternalStorageDirectory().toString();
new File(extStorageDirectory + "/one/").mkdirs();
new File(extStorageDirectory + "/one/two/).mkdirs();