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 .).
Related
I am using the following code to write to an SD card:
File dir =new File(android.os.Environment.getExternalStorageDirectory(),"MyFolder");
if(!dir.exists())
{
dir.mkdirs();
}
String filename= "MyDoople.txt";
try
{
File f = new File(dir+File.separator+filename);
FileOutputStream fOut = new FileOutputStream(f);
OutputStreamWriter myOutWriter = new OutputStreamWriter(
fOut);
myOutWriter.append("Mytest");
myOutWriter.close();
fOut.close();
Toast.makeText(getBaseContext(),
"Text Updated",
Toast.LENGTH_SHORT).show();
}
catch(Exception e)
{
e.printStackTrace();
}
However when I run my app, and then go check in the SD card, there is nothing there. Why am I not seeing the file that I created? I am using android jellybean 4.1 and have added the write permissions in the manifest file.
From your code, you're writing to the folder "MyFolder" under primary external storage.
What is the device you are using? Does it have interal storage in additional to sd card? If yes, then your file is written to the internal storage, but not the sd card.
Edit:
To access SD Card, you simply replace android.os.Environment.getExternalStorageDirectory() with the sd card path.
It is not an easy task to find the path of SD card.
One method is to use ContextCompat.getExternalFilesDirs(context, null), the first element of the returned value would be the same android.os.Environment.getExternalStorageDirectory(), the second element would be somewhere of the sdcard.
However, could be depending on your android version, the directory returned could be a sub-directory on the sd card, i.e. your application specific directory instead of the root of SD card. You have to check and manually change it if you want to find the root directory.
http://developer.android.com/reference/android/support/v4/content/ContextCompat.html#getExternalFilesDirs%28android.content.Context,%20java.lang.String%29
I have searched everywhere on stackoverflow, there are plenty of similar questions, but the answer always ends up with something that helps write on the internal storage.
I am using the File Browser snippet available here: https://github.com/vaal12/AndroidFileBrowser
After that, I get the path to the directory where I want to create my Folder.
try {
print(Environment.getExternalStorageDirectory().getAbsolutePath()); //return something like "/storage/sdcard0/"
String realPath=newDir +"/"+ getString(R.string.folder_name); //returns something like "/storage/extSdCard/..."
//realPath=realPath.replaceAll("storage", "mnt");
print(realPath);
File f = new File(realPath);
if (!f.exists()) {
f.mkdirs();
}
} catch(Exception e) {
print(e.toString());
}
This works fine when the chosen directory is on the internal sd card, but nothing happens (not even an IOException) when it's on the removable external sd card
There is good description and example about saving onto external storage on the android developer webpage. I think this would help you: http://developer.android.com/guide/topics/data/data-storage.html#filesExternal
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'm very new to Android programming and I was wondering how can I make an app take a picture and save the image to the internal storage of a device, not to the SD card, because not everyone will have an SD card.
You can try saving it as an sqlite blob. This this thread for how to do the storage. Saying "not everyone will have external storage" is a bad excuse: you should handle both cases. If instead you want to implement it as a file (a perfectly good way to do it), you can look up an external storage directory using the Environment.getExternalStorageDir() call to determine a suitable directory in which to store your files. Read the API documentation here and heed the following note:
Note: 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.
Yes, you can try to save images in sqlite blob fields. It's just a java way: and let the whole world wait :)
It's a good practice to store all your files, cache etc into /Android/data/<package_name>/files/ directory on external storage. External storage is not the only SD cards and you can get external storage path and state by Environment.getExternalStorageDirectory() and Environment.getExternalStorageState() calls (reference). If you are using API 8 or greater, you can use Context.getExternalFilesDir().
If you would like to get user's hate-rays, you can try to store files and folders in the root of external storage.
Perhaps something like this
Bitmap largeBitmap ; // save your Bitmap from data[]
FileOutputStream fileOutputStream = null;
BufferedOutputStream bos = null;
int quality = 100;
String filePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + File.separator + "myImage.jpg"
File mediaFile = new File(filePath);
try {
fileOutputStream = new FileOutputStream(pictureFile);
bos = new BufferedOutputStream(fileOutputStream);
bitmap.compress(CompressFormat.JPEG, quality, bos);
return pictureFile;
} finally {
if (bos != null) {
try {
bos.close();
} catch (IOException e) {
// ignore close error
}
}
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.