I find the answer, I should uses Storage Access Framework, It doesn't need any permission
Imagine we have saved JSON to a text file, here is the steps to restore data from it:
1- We need a method that displays a dialog to the user, so he/she can choose saved file:
private void openFile() {
Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("text/*");
someActivityResultLauncher.launch(intent);
}
2- We should implement onActivityResult to get the uri of the file that user has selected, so add someActivityResultLauncher to activity class:
ActivityResultLauncher<Intent> someActivityResultLauncher;
3- Add following methods to Activity class:
private void registerActivityResult()
{
someActivityResultLauncher = registerForActivityResult(
new ActivityResultContracts.StartActivityForResult(),
new ActivityResultCallback<ActivityResult>() {
@Override
public void onActivityResult(ActivityResult result) {
if (result.getResultCode() == Activity.RESULT_OK) {
// There are no request codes
Intent data = result.getData();
Uri uri = data.getData();
// Perform operations on the document using its URI.
try {
String txt = readTextFromUri(Setting_Activity.this, uri);
dorestore(txt);
}catch (Exception e){}
}
}
});
}
4- Call the above method in onCreate() method of activity:
@Override
protected void onCreate(Bundle savedInstanceState) {
//......
registerActivityResult();
//.....
}
5- Implement the readTextFromUri() method we used in step 3:
public static String readTextFromUri(Context context, Uri uri) throws IOException {
StringBuilder stringBuilder = new StringBuilder();
try (InputStream inputStream =
context.getContentResolver().openInputStream(uri);
BufferedReader reader = new BufferedReader(
new InputStreamReader(Objects.requireNonNull(inputStream)))) {
String line;
while ((line = reader.readLine()) != null) {
stringBuilder.append(line);
}
}
return stringBuilder.toString();
}
That's all, just implement the dorestore() method we used in step 3 to restore your json data.
in mycase it looke something like this:
private void dorestore(String data)
{
ArrayList<dbObject_user> messages = new ArrayList<>();
try {
JSONArray jsonArray = new JSONArray(data);
//....
//parsing json and saving it to app db....
//....
}
catch (Exception e)
{}
}
just call the openFile() in step 1. That's all.
