I am trying to export my realm database in external storage (actually in my cell phone)
When I press the button below method, named backupRealmNow()
, works.
public void backupRealmNow() {
Realm nowRealmForBackup = Realm.getDefaultInstance();
String filePath = "";
try {
File dir = new File(Environment.DIRECTORY_DOWNLOADS);
File exportRealmFile = new File(Environment.DIRECTORY_DOWNLOADS, "backup.realm");
filePath = exportRealmFile.getPath();
if(!dir.exists()) {
dir.mkdirs();
}
if(!exportRealmFile.exists()) {
exportRealmFile.mkdirs();
Log.d("Path", "mkdirs :: " + filePath);
}
if(exportRealmFile.exists()) {
exportRealmFile.delete();
nowRealmForBackup.writeCopyTo(exportRealmFile);
Log.d("Backup", "Success to backup " + filePath);
} else {
Log.d("Backup", "Failed to Backup");
}
} catch(Exception e) {
e.printStackTrace();
} finally {
String msg = "File exported to Path: " + filePath;
Toast.makeText(getActivity().getApplicationContext(), msg, Toast.LENGTH_LONG).show();
Log.d(TAG, msg);
nowRealmForBackup.close();
}
}
when I run above codes, my logcat said,
D/Path: mkdirs :: Download/backup.realm
D/Backup: Failed to Backup
D/ContentValues: File exported to Path: Download/backup.realm
I search the reason why this doesn't work for a while, so I check the permission (because my cell phone is running in SDK 23 Marshmellow) But, my permission was granted. Below code is checking permission which is in MainActivity.java
.
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED
&& ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this
, new String[]{android.Manifest.permission.WRITE_EXTERNAL_STORAGE, android.Manifest.permission.READ_EXTERNAL_STORAGE}
, REQUEST_RWAVAILABLE);
} else {
Log.e("Read and Write", "PERMISSION GRANTED");
}
and my logcat said "PERMISSION GRANTED".
I think the problem is exportRealmFile.mkdirs()
doesn't work. Do you know the reason why? (Logcat doesn't get any Exception at that codes as you see in log"
=========
edit : backupRealmNow()
was changed to check my package is permitted.
public void backupRealmNow() {
Realm nowRealmForBackup = Realm.getDefaultInstance();
int REQUESTCODE_WRITE = 100;
int REQUESTCODE_READ = 200;
String filePath = "";
try {
File dir = new File(Environment.DIRECTORY_DOWNLOADS);
File exportRealmFile = new File(Environment.DIRECTORY_DOWNLOADS, "backup.realm");
filePath = exportRealmFile.getPath();
if(!dir.exists()) {
dir.mkdirs();
}
if(!exportRealmFile.exists()) {
exportRealmFile.mkdirs();
if(exportRealmFile.exists()) {
Log.d("mkdirs", "Success to make dir");
} else {
Log.d("mkdirs", "Failed to make dir");
if(PermissionChecker.checkSelfPermission(getActivity().getApplicationContext(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PermissionChecker.PERMISSION_GRANTED) {
Log.e("PermissionChecker", "WRITE_EXTERNAL_STORAGE PERMISSION_DENIED so request.");
requestPermissions(new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUESTCODE_WRITE);
} else {
Log.e("PermissionChecker", "WRITE_EXTERNAL_STORAGE PERMISSION_GRANTED");
}
if(PermissionChecker.checkSelfPermission(getActivity().getApplicationContext(), Manifest.permission.READ_EXTERNAL_STORAGE) != PermissionChecker.PERMISSION_GRANTED) {
Log.e("PermissionChecker", "READ_EXTERNAL_STORAGE PERMISSION_DENIED so request.");
requestPermissions(new String[] {Manifest.permission.READ_EXTERNAL_STORAGE}, REQUESTCODE_READ);
} else {
Log.e("PermissionChecker", "READ_EXTERNAL_STORAGE PERMISSION_GRANTED");
}
}
}
if(exportRealmFile.exists()) {
exportRealmFile.delete();
nowRealmForBackup.writeCopyTo(exportRealmFile);
Log.d("Backup", "Success to backup " + filePath);
} else {
Log.d("Backup", "Failed to Backup");
}
} catch(Exception e) {
e.printStackTrace();
} finally {
String msg = "File exported to Path: " + filePath;
Toast.makeText(getActivity().getApplicationContext(), msg, Toast.LENGTH_LONG).show();
Log.d(TAG, msg);
nowRealmForBackup.close();
}
}
my logcat said,
D/mkdirs: Failed to make dir
E/PermissionChecker: WRITE_EXTERNAL_STORAGE PERMISSION_GRANTED
E/PermissionChecker: READ_EXTERNAL_STORAGE PERMISSION_GRANTED
D/Backup: Failed to Backup
D/ContentValues: File exported to Path: Download/backup.realm
You are trying to create the directory "Download" in the root directory ("/"). You need to use Environment.getExternalStoragePublicDirectory
to get the path to a public storage area, where you can actually create files and directories.