1. Create and Write File
createAndWriteButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
try {
ContentValues values = new ContentValues();
values.put(MediaStore.MediaColumns.DISPLAY_NAME, "menuCategory"); //file name
values.put(MediaStore.MediaColumns.MIME_TYPE, "text/plain"); //file extension, will automatically add to file
values.put(MediaStore.MediaColumns.RELATIVE_PATH, Environment.DIRECTORY_DOCUMENTS + "/Kamen Rider Decade/"); //end "/" is not mandatory
Uri uri = getContentResolver().insert(MediaStore.Files.getContentUri("external"), values); //important!
OutputStream outputStream = getContentResolver().openOutputStream(uri);
outputStream.write("This is menu category data.".getBytes());
outputStream.close();
Toast.makeText(view.getContext(), "File created successfully", Toast.LENGTH_SHORT).show();
} catch (IOException e) {
Toast.makeText(view.getContext(), "Fail to create file", Toast.LENGTH_SHORT).show();
}
}
});
2. Find and Read File
findAndReadButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Uri contentUri = MediaStore.Files.getContentUri("external");
String selection = MediaStore.MediaColumns.RELATIVE_PATH + "=?";
String[] selectionArgs = new String[]{Environment.DIRECTORY_DOCUMENTS + "/Kamen Rider Decade/"};
Cursor cursor = getContentResolver().query(contentUri, null, selection, selectionArgs, null);
Uri uri = null;
if (cursor.getCount() == 0) {
Toast.makeText(view.getContext(), "No file found in "" + Environment.DIRECTORY_DOCUMENTS + "/Kamen Rider Decade/"", Toast.LENGTH_LONG).show();
} else {
while (cursor.moveToNext()) {
String fileName = cursor.getString(cursor.getColumnIndex(MediaStore.MediaColumns.DISPLAY_NAME));
if (fileName.equals("menuCategory.txt")) {
long id = cursor.getLong(cursor.getColumnIndex(MediaStore.MediaColumns._ID));
uri = ContentUris.withAppendedId(contentUri, id);
break;
}
}
if (uri == null) {
Toast.makeText(view.getContext(), ""menuCategory.txt" not found", Toast.LENGTH_SHORT).show();
} else {
try {
InputStream inputStream = getContentResolver().openInputStream(uri);
int size = inputStream.available();
byte[] bytes = new byte[size];
inputStream.read(bytes);
inputStream.close();
String jsonString = new String(bytes, StandardCharsets.UTF_8);
AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
builder.setTitle("File Content");
builder.setMessage(jsonString);
builder.setPositiveButton("OK", null);
builder.create().show();
} catch (IOException e) {
Toast.makeText(view.getContext(), "Fail to read file", Toast.LENGTH_SHORT).show();
}
}
}
}
});
3. Find and Overwrite File
findAndWriteButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Uri contentUri = MediaStore.Files.getContentUri("external");
String selection = MediaStore.MediaColumns.RELATIVE_PATH + "=?";
String[] selectionArgs = new String[]{Environment.DIRECTORY_DOCUMENTS + "/Kamen Rider Decade/"}; //must include "/" in front and end
Cursor cursor = getContentResolver().query(contentUri, null, selection, selectionArgs, null);
Uri uri = null;
if (cursor.getCount() == 0) {
Toast.makeText(view.getContext(), "No file found in "" + Environment.DIRECTORY_DOCUMENTS + "/Kamen Rider Decade/"", Toast.LENGTH_LONG).show();
} else {
while (cursor.moveToNext()) {
String fileName = cursor.getString(cursor.getColumnIndex(MediaStore.MediaColumns.DISPLAY_NAME));
if (fileName.equals("menuCategory.txt")) { //must include extension
long id = cursor.getLong(cursor.getColumnIndex(MediaStore.MediaColumns._ID));
uri = ContentUris.withAppendedId(contentUri, id);
break;
}
}
if (uri == null) {
Toast.makeText(view.getContext(), ""menuCategory.txt" not found", Toast.LENGTH_SHORT).show();
} else {
try {
OutputStream outputStream = getContentResolver().openOutputStream(uri, "rwt"); //overwrite mode, see below
outputStream.write("This is overwritten data。
你就不要想起我。".getBytes());
outputStream.close();
Toast.makeText(view.getContext(), "File written successfully", Toast.LENGTH_SHORT).show();
} catch (IOException e) {
Toast.makeText(view.getContext(), "Fail to write file", Toast.LENGTH_SHORT).show();
}
}
}
}
});
Demo: https://www.youtube.com/watch?v=idsUMiWjfnM
Hope this may help you.
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