Develop Reference

creating file from uri in android 11 - getPath() not working

I want to create a file from uri in the ActivityResultCallback in android 11. I use uri.getPath() to convert the incoming uri to a file. but, it won't work in android 11. here is my codes:
private void launchGallery (){
Intent intent = new Intent(Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
launcherGallery.launch(intent);
}
ActivityResultLauncher<Intent> launcherGallery = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(),
result -> {
if (result.getResultCode() == RESULT_OK) {
Intent data = result.getData();
if (data != null) {
Uri imageUri = data.getData();
// ---> getPath() won't work in android 11 <---
File file = new File(imageUri.getPath());
// I don't want to display the image in an ImageView.
// I need a file object to pass it to this method to encrypt it
encryptImage(file);
}
}
});
so, how can I create a file from uri in android 11?

simply: you can't. if Uri would be always a File then there would be no purpose of both class existance. Uri is a "pointer" to a file, which can be read as InputStream
InputStream inputStream = getContentResolver().openInputStream(uri);
you have to read all these bytes and if you REALLY need a File then store this data in your apps Scoped Storage. if you are shure that this is an image (its declared in calling Intent) then you may try to convert this data to Bitmap.
edit: I see you've added encryptImage(..) method call, so for shure you can read Bitmap "straight from" Uri instead of a File without taking users storage space, even for a while
check out such case: note that when you run a file picker launchGallery() then inside of it you can switch folders. there is a possibility to pick file from e.g. Google Drive, or if you have installed, other web-storages (OneDrive, Dropbox etc.). you will get an Uri as a result, but this isn't a real File on local storage. so you can stream it (as through web/network) for reading entirelly, it isn't ready and available at the moment of result callback call (just after picking and returning to your app)
btw. such possibility isn't limited to Android 11 and above, it was there way earlier. just handle Uri as "pointer", do not assume it is pointing on (local) File. in some cases even if user pick local file you will get an Uri pointing on it through some ContentResolver (so use own for read data), thus this won't be a file path (won't be starting with file://)

Android webview - how to pass a large binray file to Javascript

I have a mobile app that wraps around the web-app, using webview.
The web-app has a button to open a large .zip file (e.g. 100 MB).
The user clicks a button, and selects a .zip file.
This triggers an onChange function with a variable of type File (Blob), which includes attributes like:
file name
file size
file type (application/zip)
The javascript code then parses the .zip file, extracts specific data within it and uses it within the web-app.
This works well within the web-app, when the app is called via the Chrome browser.
For example when operated in chrome browser on an Android phone, I can pull the .zip file and open it in the web-app.
I want to do the same but using the mobile app.
I am able to pick up the .zip file using a File Chooser, but I have problems to fetch the file from the Javascript code.
When calling fetch(fileUri) from the Javascript side I'm getting errors.
I'm using the following uri
/storage/emulated/0/Android/data/com.example/files/Download/file2.zip
The fetch succeeds but returns a blob with size of 165 (i.e. not the actual size of the file) which hosts the error message:
{
"error": "Not Found",
"message": "The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again."
}
The program flow is like so:
I select a .zip file via FileChooser.
In onActivityResult, the uri value is /document/msf:12858 (seen via uri = intent.getData();)
The uri needs to be mapped into a real path file url, such that the fileUrl will be passed to Javascript (via webview).
Javascript will then fetch the file using the fileUrl.
I searched how to get the real path file url when selecting a file with FileChooser, and found
this, and this links.
I wasn't able to get the real file path, so I decided to read the file and write it to another location, so I can get a file path. (this is not efficient and done just to check the functionality).
I create the new file using the following code:
InputStream stream = context.getContentResolver().openInputStream(uri);
File file2 = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), "file2.zip");
writeBytesToFile(stream, file2);
I don't see any errors when creating the file, and when creating the file, the number of bytes that are read and written to the new file are as expected.
For file2, I get a value of:
/storage/emulated/0/Android/data/com.example/files/Download/file2.zip
Then, within the Javascript code I fetch this file path.
But I'm getting a Blob with the "file-not-found" content as above.
So:
How can I verify that the file is indeed created and that the path can be fetched from Javascript?
How can I get the real file path of the original selected file, so I don't have to read and write the original file to new location just to get the file path?
Thanks
EDIT1:
I have "Intent intent" and not "Intent data" in the signature of onActivityResult.
I replaced String filePath = intent.getData() with
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
super.onActivityResult(requestCode, resultCode, intent);
try {
intent_to_resolve = new JSONObject();
if (resultCode == RESULT_OK) {
// try1
String filePath1 = intent.getData().toString();
Log.d("Verbose", "filePath1: " + filePath1);
// try2
String filePath2 = intent.toString();
Log.d("Verbose", "filePath2: " + filePath2);
...
I'm getting the following value for filePath:
filePath1: content://com.android.providers.downloads.documents/document/msf%3A12858
filePath2: Intent { dat=content://com.android.providers.downloads.documents/document/msf:12858 flg=0x43 }

How to pick file from external storage using file picker in Android

I am having a problem with selecting image file from external storage using file picker in Android. This question is the consequence of this question - No such file or diectory error in image file upload using Retrofit in Android. What my problem is opening and reading file from external storage on activity result. I want to convert result URI into File.
I read a pdf file from download folder on activity result
Uri bookUri = data.getData();
if(bookUri!=null)
{
String filePath = bookUri.toString();//bookUri.toString()
String mime = app.getMimeType(filePath);
if(mime!=null && !mime.isEmpty() && (mime.toLowerCase()=="application/pdf" || mime.toLowerCase()=="application/txt" || mime.toLowerCase()=="application/text"))
{
bookFile = new File(bookUri.getPath());
ivBookFile.setImageResource(R.drawable.book_selected);
}
else{
Toast.makeText(getBaseContext(),"Unable to process file you have chosen.",Toast.LENGTH_SHORT).show();
}
}
As you can see I used new File(bookUri.getPath()); to convert into File. The above code works well. It is working. The problem is now I am trying to open an image file in DCIM/Camera folder on activity result.
This is the code I used
Uri selectedImageUri = data.getData();
if(selectedImageUri!=null)
{
try{
bmpCoverImage = MediaStore.Images.Media.getBitmap(getContentResolver(), selectedImageUri);
imageFile = new File(selectedImageUri.getPath());
if(bmpCoverImage!=null)
{
ivCoverImage.setImageBitmap(bmpCoverImage);
}
}
catch (IOException e)
{
Toast.makeText(getBaseContext(),"An error occurred with the file selected",Toast.LENGTH_SHORT).show();
}
}
As you can see I used new File(selectedImageUri.getPath()); like I did in reading pdf file. This time the code is not working. When I do operation with the file like in previous question, it gives me error.
I used this way also
imageFile = new File(Environment.getExternalStorageDirectory(),selectedImageUri.getPath());
I got the same error. How can I open the image file correctly from external storage? How can I convert the chosen file URI from external storage into File?

I am having a problem with selecting image file from external storage using file picker in Android
If you are referring to the code that you are using in this question, you are not "using file picker". You are using ACTION_GET_CONTENT, which has never been a "file picker", nor will it ever be a "file picker".
I want to convert result URI into File.
Usually, that is not necessary. But, if that is what you want to do:
use ContentResolver and openInputStream() to get an InputStream on the content represented by the Uri
create a FileOutputStream on your desired file
use Java I/O to copy the bytes from the InputStream into the FileOutputStream
The above code works well. It is working.
It works for the small number of devices that you tested, for the specific activities that the user chose to handle the ACTION_GET_CONTENT request. It will not work on most Android devices, and it will not work in most circumstances. The only time that code will work is if the Uri has a file scheme. Most of the time, it will not. Instead, it will have a content scheme, representing content supplied by a ContentProvider.
Please how can I open the image file correctly from external storage?
If you wish to continue using ACTION_GET_CONTENT, please understand that this has nothing to do with external storage specifically. You are not getting a file, on external storage or elsewhere. You are getting a Uri. This is akin to a URL, such as the URL for this Web page. Just as a URL does not necessarily point to a file on your hard drive, a Uri does not necessarily point to a file on the filesystem. Use a ContentResolver and DocumentFile to work with the Uri and the content that it identifies.
If you want to always get files on external storage (and nowhere else), then use an actual file picker library.

java.io.IOException: Cannot make changes to file

I am using JAudioTagger library for reading and writing tags for an audio file. I am able to read the tags but unable to write them.
I am retrieving audio file path like this :
private String getSongPath(long songId) {
String path = null;
ContentResolver contentResolver = getContentResolver();
Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
String[] projection = {MediaStore.Audio.Media.DATA};
String selection = MediaStore.Audio.Media._ID + " == ?";
String[] selectionArgs = {String.valueOf(songId)};
Cursor cursor = contentResolver.query(uri, projection, selection, selectionArgs, null);
if (cursor != null) {
int pathCol = cursor.getColumnIndexOrThrow(projection[0]);
cursor.moveToFirst();
path = cursor.getString(pathCol);
cursor.close();
}
return path;
}
Then to write tags using JAudioTagger :
File songFile = new File(path); // path looks like /storage/3932-3434/Music/xyz.mp3
AudioFile audiofile = = AudioFileIO.read(songFile);
Tag tag = = audiofile.getTag();
tag.setField(FieldKey.TITLE, title);
// some more setField calls for different feilds
audiofile.commit();
The commit() method is giving following Exception :
org.jaudiotagger.audio.exceptions.CannotWriteException:
java.io.IOException: Cannot make changes to file xyz.mp3 at
org.jaudiotagger.audio.mp3.MP3File.commit(MP3File.java:799) at
com.techapps.musicplayerplus.MainActivity$17.onClick(MainActivity.java:2125)
at
android.support.v7.app.AlertController$ButtonHandler.handleMessage(AlertController.java:157)
at android.os.Handler.dispatchMessage(Handler.java:102) at
android.os.Looper.loop(Looper.java:148) at
android.app.ActivityThread.main(ActivityThread.java:5417) 06-18
10:59:48.134 8802-8802/com.techapps.musicplayerplus W/System.err:
at java.lang.reflect.Method.invoke(Native Method) at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) Caused
by: java.io.IOException: Cannot make changes to file Saibo.mp3 at
org.jaudiotagger.audio.mp3.MP3File.precheck(MP3File.java:824) at
org.jaudiotagger.audio.mp3.MP3File.save(MP3File.java:850) at
org.jaudiotagger.audio.mp3.MP3File.save(MP3File.java:783) at
org.jaudiotagger.audio.mp3.MP3File.commit(MP3File.java:795)
I am running this code on Android 6 while my app is targeted at SDK 22. I have also mentioned following permission in manifest.
android.permission.WRITE_EXTERNAL_STORAGE
Still I am unable to write to SD card. Please help me. Thanks in advance.

You have to use Storage Access Framework (SAF) to access SD Card from API 19 (Kitkat) onward.
First we need to ask user to provide a URI of the folder we want to access. If we want access to entire SD card, user needs to provide URI of SD card's root folder.
For example, when user hits Edit button, we have to first show hint dialog box, asking user to select required directory in SD Card which we want to access. You can display following image in hint dialog box to ask user to select root directory of SD Card :
When user dismisses hint dialog box, you need to trigger Storage Access Framework :
private void triggerStorageAccessFramework() {
Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
startActivityForResult(intent, REQUEST_CODE_STORAGE_ACCESS);
}
public final void onActivityResult(final int requestCode, final int resultCode, final Intent resultData) {
if (resultCode == Activity.RESULT_OK) {
if (requestCode == REQUEST_CODE_STORAGE_ACCESS) {
Uri treeUri = null;
// Get Uri from Storage Access Framework.
treeUri = resultData.getData();
pickedDir= DocumentFile.fromTreeUri(this, treeUri);
if (!isSDCardRootDirectoryUri(treeUri)) {
Toast.makeText(this, "Wrong directory selected. Please select SD Card root directory.", Toast.LENGTH_LONG).show();
createSDCardHintDialog().show();
return;
}
// Persist URI in shared preference so that you can use it later.
SharedPreferences sharedPreferences = getSharedPreferences(App.PREFERENCE_FILENAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(App.SDCARD_URI_KEY, treeUri.toString());
editor.apply();
// Persist access permissions, so you dont have to ask again
final int takeFlags = resultData.getFlags() & (Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
getContentResolver().takePersistableUriPermission(treeUri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
}
}
private boolean isSDCardRootDirectoryUri(Uri treeUri) {
String uriString = treeUri.toString();
return uriString.endsWith("%3A");
}
Once you get Uri of user picked directory, you can perform write operation using SAF : (creadit : this answer )
public void writeFile(DocumentFile pickedDir) {
try {
DocumentFile file = pickedDir.createFile("image/jpeg", "try2.jpg");
OutputStream out = getContentResolver().openOutputStream(file.getUri());
try {
// write the image content
} finally {
out.close();
}
} catch (IOException e) {
throw new RuntimeException("Something went wrong : " + e.getMessage(), e);
}
}

It could be that you pointing to non existing file.
Check your path file by using Log.
Log.d("Activity", "path = " + path);

Android-M or API 23 introduced Runtime Permissions for reducing security flaws in android device.
To update your apps using Google Play services to handle Android 6.0 permissions, it’s good practice to manage the user’s expectations in setting permissions that the runtime may require. The following link will help you avoid potential issues.
https://developer.android.com/training/permissions/requesting.html

have you declared the permission
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> ?

I saw that you already created an issue in the JAudioTagger GitHub repository which was advisable, but never got a universally working solution. My findings so far:
The answer mentioning SAF is correct, but it won't help you as SAF will provide a DocumentFile, not a File.
You might try to modify JAudioTagger to your needs, replacing File with DocumentFile, but the latter one has not all functions you will need.
Also InputStream and OutputStream will not help you, as JAudioTagger needs File and internally heavily uses RandomAccessFile which is not available either.
Google "forgot" to provide some getRandomAccessFileFromUri() which makes things even worse (Yes, there are hacks using Java reflection to work around this limitation...).
The "/proc/self/fd" method (How to handle SAF when I can only handle File or file-path?) will also not work immediately, as JAudioTagger needs copy and renaming functions that are not applicable to this kind of files. Particularly JAudioTagger will not find a suitable file name extension like ".m4a". Of course you could try to change JAudioTagger accordingly.
You might follow the advice to make a copy of the file to your personal storage, then apply JAudioTagger to it and finally copy it back to SD card, but:
If you want to use JAudioTagger to read from SD card, this will, as announced by Google, fail with Android 10. Starting with that version, you will not even have read access to the SD card via the File interface.
Further, the File interface gives you read access to SD cards with Android 9 and below, but not to other SAF devices, like USB OTG memory or SMB shares etc.
Of course you could also copy each file in order to read its metadata, but this will be awfully slow and is not suitable if you have more than a few files.
So my current advices are:
Try the "/proc/self/fd" method and modify JAudioTagger accordingly.
If the changes are too heavy, use the fd method for reading the tags and the copy method for writing.
BTW: I am currently modifying an older version of JAudioTagger for using both File and DocumentFile transparently, but the changes are tremendous, bear a high risk, need some help classes, and the work is unfinished, yet.
BTSW: The DocumentFile functions are painfully slow, compared to the File functions.

Android: Content type error using ACTION_VIEW with a local file

I'm trying to post a notification that lets the user open a locally stored file. My code looks like this:
Intent notificationIntent = new Intent(Intent.ACTION_VIEW);
notificationIntent.setAction(android.content.Intent.ACTION_VIEW);
Uri uri = Uri.fromFile(new File(filename));
notificationIntent.setData(uri);
Where "filename" is the full path to a locally stored file, usually in the /mnt/sdcard/download directory. The files I want to display are of various types: images, PDF documents, HTML, etc.
This works, but sometimes Android tries to open the file as the wrong type. For example, a jpeg file will open in a web browser view and instead of seeing the image, I see the binary data from the file displayed as text. Other times it works file. For example, some PDF files correctly open in a PDF viewer and some do not.
I'm not sure why this is. The documentation says I should not have to pass an explicit content type. If I do set the content type explicitly, things seem to work fine. The problem is, I don't always know what the content type should be (the file is downloaded from an external source and can be anything, and no, the MIME type is not in the HTTP headers, I checked for that).
What can I do here? Is there some function I can call with a filename to have Android return me the best content type for that file? Moreover, why is this not happening automatically when the Intent is processed?
Thanks.

You've most likely figured this out; I'm posting in case someone else is stuck on this. I do the following to get the mime-type of the file:
//Get the file path
Uri path = Uri.fromFile(file);
MimeTypeMap type_map = MimeTypeMap.getSingleton();
//Get the extension from the path
String extension = MimeTypeMap.getFileExtensionFromUrl(path.toString());
extension = extension.toLowerCase();
if (extension.contains(".")) {
extension = extension.substring(extension.lastIndexOf("."));
}
String mime_type = type_map.getMimeTypeFromExtension(extension);