I am working on an app where I want to be able to export and import some data from the app, on a .txt file.
The minimum API of the app is 21.
The export part works well, but I am having trouble with the import part.
I open the file explorer :
butImportPatient.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent();
intent.setAction(Intent.ACTION_OPEN_DOCUMENT);
intent.setType("*/*");
startActivityForResult(intent, IMPORTPATIENT_ACTIVITY_REQUEST_CODE);
}
});
This looks like it is working.
But my onActivityResult doesn't work, I didn't find how I can get the file from the Uri.
For now, here is my code :
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == IMPORTPATIENT_ACTIVITY_REQUEST_CODE && resultCode == RESULT_OK) {
File file = new File(data.getData().getPath()) ;
String path = file.getAbsolutePath() ;
StringBuilder text = new StringBuilder();
try {
BufferedReader br = new BufferedReader(new FileReader(path));
String line;
while ((line = br.readLine()) != null) {
text.append(line);
text.append("\n");
}
br.close();
} catch (IOException e) {
e.printStackTrace();
}
AlertDialog.Builder builder = new AlertDialog.Builder(this) ;
builder.setMessage(path)
.show() ;
}
}
It is a mix of multiple posts I saw here, but none seems to work.
I get this path :
/document/home:List.txt
It creates FileNotFoundException. How can I get the real path of the file ?
I didn't find how I can get the file from the Uri.
There is no file. ACTION_OPEN_DOCUMENT and ACTION_GET_CONTENT do not open a file. They open a document. That document might be a file. It might not.
That Uri might point to:
A local file on external storage
A local file on internal storage for the other app
A local file on removable storage
A local file that is encrypted and needs to be decrypted on the fly
A stream of bytes held in a BLOB column in a database
A piece of content that needs to be downloaded by the other app first
...and so on
How can I get the real path of the file ?
You don't.
If you wish to only accept files, integrate a file chooser library instead of using ACTION_OPEN_DOCUMENT or
ACTION_GET_CONTENT. Just bear in mind that filesystem access to external storage is limited on Android 10+.
If you use ACTION_GET_CONTENT, and the scheme of the Uri that you get is file, then getPath() will be a filesystem path.
Otherwise, you need to understand that you have no idea where the document is coming from, and stop thinking in terms of "real path of the file". Use ContentResolver and openInputStream() to make a copy of the content to some file that you control, then work with that file.
Related
In Android Studio:
This app must use COMTRADE files. The COMTRADE files are *.cfg *.dat and *.rio files. For example, (user.cfg, user.dat and user.rio). The main file is *.cfg file, so the user must browse by SAF to find *.cfg files, when the user select this file, the app must load other files ( *.dat and *.rio) automatically.
I can not use <uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/> for android level 30
So I have to use Storage Access Framework, By below code the user browse *.cfg files and select a file like user.cfg
if(SDK_INT >= Build.VERSION_CODES.R)
{
Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("*/*");
Act.startActivityForResult(intent, 111);
}
else
{...}
Then SAF return URI of that user.cfg file, and the app does not have any URI of other files to load.
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
if(requestCode == 111)
{
if (resultCode == Activity.RESULT_OK)
{
if (data != null)
{
try
{
Uri uri = null;
uri = data.getData();
InputStreamReader inputStreamReader = new InputStreamReader(getContentResolver().openInputStream(uri));
BufferedReader br = new BufferedReader(inputStreamReader);
// I want URI of user.dat how?
InputStreamReader inputStreamReader1 = new InputStreamReader(getContentResolver().openInputStream(uri1));
BufferedReader br1 = new BufferedReader(inputStreamReader1);
....
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
}
}
}
Please help me how can I do this? Thanks.
Please help me how can I do this?
You cannot do this, at least by means of using ACTION_OPEN_DOCUMENT, unless you ask the user to open each of your three documents in turn. Just because the user selected a .cfg file does not mean that you have any rights to any other files, including those adjacent to it.
You could try using ACTION_OPEN_DOCUMENT_TREE and let the user choose the document tree that contains your desired files. From there, you can:
Use DocumentFile.fromTreeUri() to get a DocumentFile representing the tree
Call listFiles() on that DocumentFile to get the direct contents of that tree, in the form of a list of DocumentFile objects
Call getName() on each of those to get their display names, then see which names have your desired file extensions and matching base names (foo.cfg and foo.rio and foo.dat)
For those that you want to use, call getUri() on the DocumentFile to get a Uri to use with ContentResolver and openInputStream() to read in the content
I am trying to write to a file that is located in the SDCard, I found out that I need special permission for removable storage something that is not found in any known permission handler plugin for flutter (i tried simple_permission and permission_handler with no use).
I tried to acquire those permissions using the android side of things, so I wrote a simple function that would show the dialog and the user would allow the app to modify the content of the SDCard.
even after acquiring the rights to the SDCARD, I still get the same permissions denied error when trying to save files to the SDCard when using File.writeAsStringSync method.
I want to know if there is any known way/hack/workaround to save files in SDCards in flutter.
The android code i used is the same from this answer : https://stackoverflow.com/a/55024683/6641693
NOTE : I am targetting android 7 and beyond but not android 11.
I solved This, by ditching the dart file saving and using the android SAF.
First, what I did was try to get the sdCard modification permissions.
After that, I get to save the files I need.
here is the code I used to get the permissions ( aka the "allow this app to modify content on your sdCard" dialog )
public void takeCardUriPermission(String sdCardRootPath) {
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
File sdCard = new File(sdCardRootPath);
StorageManager storageManager = (StorageManager) getSystemService(Context.STORAGE_SERVICE);
StorageVolume storageVolume = storageManager.getStorageVolume(sdCard);
Intent intent = storageVolume.createAccessIntent(null);
try {
startActivityForResult(intent, 4010);
} catch (ActivityNotFoundException e) {
Log.e("TUNE-IN ANDROID", "takeCardUriPermission: "+e);
}
}
}
protected void onActivityResult(int requestCode, int resultCode, #Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 4010) {
Uri uri = data.getData();
grantUriPermission(getPackageName(), uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION |
Intent.FLAG_GRANT_READ_URI_PERMISSION);
final int takeFlags = data.getFlags() & (Intent.FLAG_GRANT_WRITE_URI_PERMISSION |
Intent.FLAG_GRANT_READ_URI_PERMISSION);
getContentResolver().takePersistableUriPermission(uri, takeFlags);
methodChannel.invokeMethod("resolveWithSDCardUri",getUri().toString());
}
}
public Uri getUri() {
List<UriPermission> persistedUriPermissions = getContentResolver().getPersistedUriPermissions();
if (persistedUriPermissions.size() > 0) {
UriPermission uriPermission = persistedUriPermissions.get(0);
return uriPermission.getUri();
}
return null;
}
So in order to start the whole permissions acquiring process, you have to first call takeCardUriPermission and passing the URI of the sdCard path.
Note: on my FlutterActivity, i am able to get the sdCardPath directly using getExternalCacheDirs()[1].toString()
After calling takeCardUriPermission and once the allow button is pressed (or the decline) an activity result event will be called and the onActivtyResult method will be called. the requestCode check is useful when you have multiple events and you need to filter this one out.
The activity result code will give the app permissions to modify the files on the sdCard.
The getUri method is the one that we will be using afterwards when trying to save bytes to a file, it returns the URI of the SDCard that we selected (you can have multiple sdCards).
Saving Files
What I used to save a file is a straightforward method. First we need to get the URI of the sdCard and create a Documentfile out of it, then we go through the hierarchy of that directory (DocumentFile can reference files and directories) to find the needed file based on it's URI.
We do this search by splitting the file URI into parts and then navigating the hierarchy by testing if each part exists or not. Once we test all the parts we would have reached our file, if it exists, or we were stuck at the last directory we got to.
the resulting of this iteration is a DocumentFile that we can execute operations on and with.
the following is the full file saving code :
String filepath = (String) arguments.get("filepath");
final byte[] bytes = methodCall.argument("bytes");
try{
if(filepath==null || bytes==null)throw new Exception("Arguments Not found");
DocumentFile documentFile = DocumentFile.fromTreeUri(getApplicationContext(), getUri());
String[] parts = filepath.split("/");
for (int i = 0; i < parts.length; i++) {
DocumentFile nextfile = documentFile.findFile(parts[i]);
if(nextfile!=null){
documentFile=nextfile;
}
}
if(documentFile!=null && documentFile.isFile()){
OutputStream out = getContentResolver().openOutputStream(documentFile.getUri());
out.write(bytes);
out.close();
}else{
throw new Exception("File Not Found");
}
}catch (Exception e){
result.error("400",e.getMessage(),e);
return;
}
result.success(true);
Note: in my code, I am calling this under the MethodChannel's MethodCallHandler which will give me the argument I need: filePath which is the String URI of the file I want to write to and the bytes byte array representing the data I want to save. The same can be said for the result.success
The file writing code is simple: open the file, write the data and close the file.
I am working on an app where I want to be able to export and import some data from the app, on a .txt file.
The minimum API of the app is 21.
The export part works well, but I am having trouble with the import part.
I open the file explorer :
butImportPatient.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent();
intent.setAction(Intent.ACTION_OPEN_DOCUMENT);
intent.setType("*/*");
startActivityForResult(intent, IMPORTPATIENT_ACTIVITY_REQUEST_CODE);
}
});
This looks like it is working.
But my onActivityResult doesn't work, I didn't find how I can get the file from the Uri.
For now, here is my code :
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == IMPORTPATIENT_ACTIVITY_REQUEST_CODE && resultCode == RESULT_OK) {
File file = new File(data.getData().getPath()) ;
String path = file.getAbsolutePath() ;
StringBuilder text = new StringBuilder();
try {
BufferedReader br = new BufferedReader(new FileReader(path));
String line;
while ((line = br.readLine()) != null) {
text.append(line);
text.append("\n");
}
br.close();
} catch (IOException e) {
e.printStackTrace();
}
AlertDialog.Builder builder = new AlertDialog.Builder(this) ;
builder.setMessage(path)
.show() ;
}
}
It is a mix of multiple posts I saw here, but none seems to work.
I get this path :
/document/home:List.txt
It creates FileNotFoundException. How can I get the real path of the file ?
I didn't find how I can get the file from the Uri.
There is no file. ACTION_OPEN_DOCUMENT and ACTION_GET_CONTENT do not open a file. They open a document. That document might be a file. It might not.
That Uri might point to:
A local file on external storage
A local file on internal storage for the other app
A local file on removable storage
A local file that is encrypted and needs to be decrypted on the fly
A stream of bytes held in a BLOB column in a database
A piece of content that needs to be downloaded by the other app first
...and so on
How can I get the real path of the file ?
You don't.
If you wish to only accept files, integrate a file chooser library instead of using ACTION_OPEN_DOCUMENT or
ACTION_GET_CONTENT. Just bear in mind that filesystem access to external storage is limited on Android 10+.
If you use ACTION_GET_CONTENT, and the scheme of the Uri that you get is file, then getPath() will be a filesystem path.
Otherwise, you need to understand that you have no idea where the document is coming from, and stop thinking in terms of "real path of the file". Use ContentResolver and openInputStream() to make a copy of the content to some file that you control, then work with that file.
I am working on an app where I want to be able to export and import some data from the app, on a .txt file.
The minimum API of the app is 21.
The export part works well, but I am having trouble with the import part.
I open the file explorer :
butImportPatient.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent();
intent.setAction(Intent.ACTION_OPEN_DOCUMENT);
intent.setType("*/*");
startActivityForResult(intent, IMPORTPATIENT_ACTIVITY_REQUEST_CODE);
}
});
This looks like it is working.
But my onActivityResult doesn't work, I didn't find how I can get the file from the Uri.
For now, here is my code :
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == IMPORTPATIENT_ACTIVITY_REQUEST_CODE && resultCode == RESULT_OK) {
File file = new File(data.getData().getPath()) ;
String path = file.getAbsolutePath() ;
StringBuilder text = new StringBuilder();
try {
BufferedReader br = new BufferedReader(new FileReader(path));
String line;
while ((line = br.readLine()) != null) {
text.append(line);
text.append("\n");
}
br.close();
} catch (IOException e) {
e.printStackTrace();
}
AlertDialog.Builder builder = new AlertDialog.Builder(this) ;
builder.setMessage(path)
.show() ;
}
}
It is a mix of multiple posts I saw here, but none seems to work.
I get this path :
/document/home:List.txt
It creates FileNotFoundException. How can I get the real path of the file ?
I didn't find how I can get the file from the Uri.
There is no file. ACTION_OPEN_DOCUMENT and ACTION_GET_CONTENT do not open a file. They open a document. That document might be a file. It might not.
That Uri might point to:
A local file on external storage
A local file on internal storage for the other app
A local file on removable storage
A local file that is encrypted and needs to be decrypted on the fly
A stream of bytes held in a BLOB column in a database
A piece of content that needs to be downloaded by the other app first
...and so on
How can I get the real path of the file ?
You don't.
If you wish to only accept files, integrate a file chooser library instead of using ACTION_OPEN_DOCUMENT or
ACTION_GET_CONTENT. Just bear in mind that filesystem access to external storage is limited on Android 10+.
If you use ACTION_GET_CONTENT, and the scheme of the Uri that you get is file, then getPath() will be a filesystem path.
Otherwise, you need to understand that you have no idea where the document is coming from, and stop thinking in terms of "real path of the file". Use ContentResolver and openInputStream() to make a copy of the content to some file that you control, then work with that file.
In my app I have this code allowing the user to select a file :
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("text/plain");
startActivityForResult(intent,1);
The user can select the .txt file from anywhere in his phone, even from google drive. When the file selection is done I retrieve a Uri object corresponding to the file. The problem is I can't use this Uri to read the file because it is not valid. Here is my code :
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1) {
if (resultCode == RESULT_OK) {
Uri uri = data.getData();
File file = new File(uri.toString());
try{
InputStream inputStream = new FileInputStream(file);
int content;
while ((content = inputStream.read()) != -1) {
Log.d("===>", String.valueOf((char) content));
}
}catch (Exception e){
Log.d("===>", e.toString());
}
}
}
}
I always get a fileNotFoundException. My question is, is there a way to read the selected file (without knowing in advance the location it will come from). And if not, is there a way to copy the selected file in a folder from which I would easily get it ?
The problem is I can't use this Uri to read the file because it is not valid.
That is because a Uri is not a file.
is there a way to read the selected file (without knowing in advance the location it will come from)
The user did not select a file. The user selected a piece of content.
To consume the content represented by the Uri, call openInputStream() on a ContentResolver, passing in the Uri. This gives you an InputStream that you can use to read in the content.