I'm writing an app that downloads photos from a digital camera. What would be the most appropriate place to save them to? Must be external storage since gigabytes of images are expected.
Saving files that should be shared
If you want to save files that are not specific to your application and that should not be deleted when your application is uninstalled, save them to one of the public directories on the external storage. These directories lay at the root of the external storage, such as Music/, Pictures/, Ringtones/, and others.
In API Level 8 or greater, use getExternalStoragePublicDirectory(),
passing it the type of public directory you want, such as
DIRECTORY_MUSIC, DIRECTORY_PICTURES, DIRECTORY_RINGTONES, or others.
This method will create the appropriate directory if necessary.
If you're using API Level 7 or lower, use getExternalStorageDirectory() to open a File that represents the root
of the external storage, then save your shared files in one of the
following directories:
Music/ - Media scanner classifies all media found here as user music.
Podcasts/ - Media scanner classifies all media found here as a
podcast.
Ringtones/ - Media scanner classifies all media found here as
a ringtone.
Alarms/ - Media scanner classifies all media found here as
an alarm sound.
Notifications/ - Media scanner classifies all media
found here as a notification sound.
Pictures/ - All photos (excluding
those taken with the camera).
Movies/ - All movies (excluding those
taken with the camcorder).
Download/ - Miscellaneous downloads.
filesExternal
External Storage is the best place to store images and the default location is to get it using
Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)
If you want to create a folder inside default picture Directory then use below
Example code:
File storageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)
+ "/Your_folder_name");
Here is method, this is how I am saving Bitmap image to default picture directory:
private String saveImage(Bitmap image) {
String savedImagePath = null;
Date d = new Date();
CharSequence s = DateFormat.format("MM-dd-yy hh-mm-ss", d.getTime());
String imageFileName = "IMG" + s + count + ".jpg";
File storageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES)
+ "/Your_folder_name");
boolean success = true;
if (!storageDir.exists()) {
success = storageDir.mkdirs();
}
if (success) {
File imageFile = new File(storageDir, imageFileName);
savedImagePath = imageFile.getAbsolutePath();
try {
OutputStream fOut = new FileOutputStream(imageFile);
image.compress(Bitmap.CompressFormat.JPEG, 100, fOut);
fOut.close();
} catch (Exception e) {
e.printStackTrace();
}
// Add the image to the system gallery
//galleryAddPic(savedImagePath);
//Toast.makeText(mContext, "IMAGE SAVED", Toast.LENGTH_LONG).show();
}
return savedImagePath;
}
External storage, since you will need lots of space.
If you want them to be accessible by other applications, just put them in the DCIM folder with the camera's original folder name, (android's is 100ANDROID, other cameras have other ones). Users expect pictures to be stored there, as do other applications.
Here is an example from Google. Note that you MUST define <provider> in AndroidManifest.xml and the res/xml/file_paths.xml according to description. However, to use getExternalStoragePublicDirectory() I had to set path="." in the file_paths.xml file..
Related
Currently, we have an app that we are targeting Android 10 and right now are using the legacy storage API. Our app communicates via Bluetooth sensors and reads and writes raw data in CSV files in a subfolder in the main directory, with that subfolder having subfolders for each user.
I know Android 11 will enforce Scoped Storage. I would like to know, is our use case outside of the Scoped Storage requirement? It appears our use case isn't supported by MediaStore. If not, how would we go about this?
MediaStore APIs are just for media files - images, videos, and audio.
You can store all files in the app's private folder and add an export option to your app (maybe compress the whole structure to an archive). So a user will be able to store or send it wherever they want.
In this case, you need to use FileProvider to expose the file from the private directory.
reads and writes raw data in CSV files in a subfolder in the main directory,
For an Android 11 device you can create your own folders an subfolders in the Documents directory of what you call the 'main folder'.
And for using the MediaStore: you can also write any file to that Documents directory. Well in a subfolder if not directly.
I'm in a similar boat. This may help you get started.
public class FirstFragment extends Fragment {
...
public void fauxMakeCsvSurveyFile() {
File appDir = new File(getContext().getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), "Field_data");
appDir.mkdirs();
try {
String storageState = Environment.getExternalStorageState();
if (storageState.equals(Environment.MEDIA_MOUNTED)) {
File file = new File(getContext().getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS) + "/Field_data/" + "OutputFile.csv");
FileOutputStream fos = new FileOutputStream(file);
String text = "Hello, world!";
fos.write(text.getBytes());
fos.close();
}
} catch (IOException e) {
Log.e("IOException", "exception in createNewFile() method");
}
}
...
}
We have an app which downloads images and store them on the device. The image is stored, but we are not able to see our app folder when we open the gallery. Here is the code we use to create directory:
public File getDataFolder(Context context) {
File dataDir = null;
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
dataDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + File.separator + "MYAPPNAME");
if(!dataDir.isDirectory()) {
dataDir.mkdirs();
}
}
if(!dataDir.isDirectory()) {
dataDir = context.getFilesDir();
}
return dataDir;
}
Also we have noticed, Folder is visible in Jelly bean but not in KitKat+ devices. Why it's not visible in gallery? (files are .jpg format)
Have you tried using getExternalFilesDirs()?
Use getExternalFilesDirs() (note the plural). If that returns more than one entry, the second and subsequent ones are on removable media. Those directories you can read and write to without any permissions on Android 4.4.
From this answer https://stackoverflow.com/a/26006099/5837758.
EDIT
If the folder appears after rebooting, then you need to add your image to the gallery. From the Taking Photos Simply tutorial (http://developer.android.com/training/camera/photobasics.html):
private void galleryAddPic() {
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
File f = new File(mCurrentPhotoPath);
Uri contentUri = Uri.fromFile(f);
mediaScanIntent.setData(contentUri);
this.sendBroadcast(mediaScanIntent);
}
You have to invoke the media scanner on your new file upon that file being visible in the Gallery without reboot. Call the media scaner after ever file saved.
Only a few lines of code will do. Code has been published very often on this site.
Prior to Android Kitkat, third-party apps had access to external storage, but from Kitkat, this permission is revoked. Now you can store data in the internal memory of the device only.
I'm trying to write a file to my phone.
I used Environment.getDataDirectory() to know the internal storage's path and Environment.getExternamStorageDirectory() to know the external storage's path.
But when I use Environment.getExternalStorageDirectory() as path, the file is created in internal storage. And when I use Environment.GetDataStorage() as the path, the file is not created. (I am not sure, but I can't find it in the explorer app, at least.)
I think my phone's internal storage is perceived as external storage.(In my case, it has 32 GB amount of storage)
I want to know removable storage(e.g. micro SD card) path. What should I do?
From the official documentation for getExternalStorageDirectory()
Don't be confused by the word "external" here. This directory
can better be thought as media/shared storage. It is a filesystem that
can hold a relatively large amount of data and that is shared across
all applications (does not enforce permissions). Traditionally this is
an SD card, but it may also be implemented as built-in storage in a
device that is distinct from the protected internal storage and can be
mounted as a filesystem on a computer.
So, it can be different from built-in storage in a device.
For your case, you could use getExternalStoragePublicDirectory(java.lang.String)
This is where the user will typically place and manage their own
files
The path here should be one of DIRECTORY_MUSIC, DIRECTORY_PODCASTS,
DIRECTORY_RINGTONES, DIRECTORY_ALARMS, DIRECTORY_NOTIFICATIONS,
DIRECTORY_PICTURES, DIRECTORY_MOVIES, DIRECTORY_DOWNLOADS, or
DIRECTORY_DCIM. May not be null.
Or if you want your data to be deleted whenever the user uninstalls your app, you could use getExternalFilesDir().
As these files are internal to the applications, and not typically visible to the user as media.
Also there are some differences between getFilesDir() and getExternalFilesDir()
External files are not always available: they will disappear if the user mounts the external storage on a computer or removes it. See the APIs on environment for information in the storage state.
There is no security enforced with these files. For example, any application holding WRITE_EXTERNAL_STORAGE can write to these files.
Try this...
static String storagestate = Environment.getExternalStorageState();
private static FileOutputStream outStream;
private static File imageFilepath;
public static String saveImage(Bitmap bitmap) {
File folder = null;
// Check for SD card
if (storagestate.equals(Environment.MEDIA_MOUNTED)) {
folder = new File(Environment.getExternalStorageDirectory(),
"*YourStorageNameInDevice");
if (!folder.exists()) {
folder.mkdir();
}
outStream = null;
String timestamp = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS")
.format(new Date());
// Getting filepath
imageFilepath = new File(folder.getPath() + File.separator
+ timestamp + ".PNG");
try {
outStream = new FileOutputStream(imageFilepath);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, outStream);
outStream.flush();
outStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
return imageFilepath.getAbsolutePath();
}
}
I know there have been questions about this, but for some reason nothing seems to work for me.
I'm trying to get 2 text files to save to the SD card from my app. It correctly creates the directory and the files, but always to the Internal Storage, never the External Storage. I do have the permissions in place as well in the Manifest.
try {
File sdCard = Environment.getExternalStorageDirectory();
File myFile = new File(sdCard.getAbsolutePath() + "/rlgl");
myFile.mkdir();
// myFile.createNewFile();
String newLine = System.getProperty("line.separator");
File file = new File(myFile, "rlgls.txt");
if(file.exists()) {
} else if (!file.exists()){
FileOutputStream fOut = new FileOutputStream(file);
OutputStreamWriter myOutWriter =
new OutputStreamWriter(fOut);
for (int i = 0; i < 30; i++) {
myOutWriter.append("0.0" + newLine);
}
myOutWriter.close();
fOut.close();
}
} catch (IOException e) {
e.printStackTrace();
}
This is the code that I am using. I've followed directions from other Stackoverflow responses but it never goes to the SD Card. Is there something I'm doing wrong? Also a follow up question is there a way for me to use the above code in order to make the files invisible to the user. They should have no reason to open them. Thanks in advance.
It correctly creates the directory and the files, but always to the Internal Storage, never the External Storage
No, it places them on external storage. What the user sees as internal storage is what the developer sees as external storage. Internal storage is accessed via methods like getFilesDir(). And none of those are removable storage, such as some form of SD card.
Also a follow up question is there a way for me to use the above code in order to make the files invisible to the user. They should have no reason to open them.
Then put them on internal storage.
my app can't read/write from/to the files when there is a "." in front of their names
I find that very difficult to believe. The . prefix makes them not show up by default in some file browsers, but that's it. Users can get to them (if they are on external storage), and apps can get to them (subject to the same rules as any other files, those without a leading .).
Im trying to save data to sdCard first i tried to saave it privately within app directory on externalStorage using getExternalFilesDir but gives me nullPointerException so i tried the other way given below it worked but when i want to store files into a custom directory that i want to named myself it give me error:
FileOutputStream os;
dirName = "/mydirectory/";
try {
if (android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED)){
File sdCard = Environment.getExternalStorageDirectory();
File dir = new File (sdCard.getAbsolutePath() + dirName);
dir.mkdirs();
//File file = new File(this.getExternalFilesDir(null), this.dirName+fileName); //this function give null pointer exception so im using other one
File file = new File(dir, dirName+fileName);
os = new FileOutputStream(file);
}else{
os = context.openFileOutput(fileName, MODE_PRIVATE);
}
resizedBitmap.compress(CompressFormat.PNG, 100, os);
os.flush();
os.close();
}catch(Exception e){
}
ErrorLog:
java.io.FileNotFoundException: /mnt/sdcard/mvc/mvc/myfile2.png (No such file or directory)
Your directory "/mnt/sdcard/mvc/mvc" may not exist. What about changing your path to store the image in the Environment.getExternalStorageDirectory() path and then working from there?
Also, as Robert pointed out, make sure you have write permission to external storage in your manifest.
Edit - to create directories:
String root = Environment.getExternalStorageDirectory().toString();
new File(root + "/mvc/mvc").mkdirs();
Then you can save a file to root + "/mvc/mvc/foo.png".
Have you requested permission to write onto SD card? Add the following string to you app manifest:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
You should check if you have added the required permission android.permission-group.STORAGE to your app. Without that permission you won't be able to access anything on the SD-Card.
BTW: On the Android system I know the SD-card is mounted on /sdcard not /mnt/sdcard
I found this book to be very helpful: "Pro Android Media: Developing Graphics, Music, Video, and Rich Media Apps for Smartphones and Tablets". I noticed a part that allows saving images and stuff to the SD card.