I am looking for a way to detect and access removable sd cards on a variety of Android devices (Samsung, Motorola, LG, Sony, HTC).
I also need to be compatible with 2.2 so Environment.isExternalStorageRemovable()
is unavailable for me.
Motorola has its own library, and for Samsung I can detect the existence of /external_sd/
I have no clue for the rest of them. For example, I have seen a /_ExternalSD/
on some LG's but it the directory remains even when the SD is removed.
A bonus question: will the ACTION_MEDIA_MOUNTED
intent be broadcast for any of them
Any hint on this would be very helpful.
Here's a class I use to find all sdcards on a device; built in and removable. I've been using it on Ice Cream Sandwich, but it should work at 2x levels.
public class GetRemovableDevice {
private final static String TAG = "GetRemoveableDevice";
public GetRemovableDevice() {
}
public static String[] getDirectories() {
MyLog.d(TAG, "getStorageDirectories");
File tempFile;
String[] directories = null;
String[] splits;
ArrayList<String> arrayList = new ArrayList<String>();
BufferedReader bufferedReader = null;
String lineRead;
try {
arrayList.clear(); // redundant, but what the hey
bufferedReader = new BufferedReader(new FileReader("/proc/mounts"));
while ((lineRead = bufferedReader.readLine()) != null) {
MyLog.d(TAG, "lineRead: " + lineRead);
splits = lineRead.split(" ");
// System external storage
if (splits[1].equals(Environment.getExternalStorageDirectory()
.getPath())) {
arrayList.add(splits[1]);
MyLog.d(TAG, "gesd split 1: " + splits[1]);
continue;
}
// skip if not external storage device
if (!splits[0].contains("/dev/block/")) {
continue;
}
// skip if mtdblock device
if (splits[0].contains("/dev/block/mtdblock")) {
continue;
}
// skip if not in /mnt node
if (!splits[1].contains("/mnt")) {
continue;
}
// skip these names
if (splits[1].contains("/secure")) {
continue;
}
if (splits[1].contains("/mnt/asec")) {
continue;
}
// Eliminate if not a directory or fully accessible
tempFile = new File(splits[1]);
if (!tempFile.exists()) {
continue;
}
if (!tempFile.isDirectory()) {
continue;
}
if (!tempFile.canRead()) {
continue;
}
if (!tempFile.canWrite()) {
continue;
}
// Met all the criteria, assume sdcard
arrayList.add(splits[1]);
}
} catch (FileNotFoundException e) {
} catch (IOException e) {
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException e) {
}
}
}
// Send list back to caller
if (arrayList.size() == 0) {
arrayList.add("sdcard not found");
}
directories = new String[arrayList.size()];
for (int i = 0; i < arrayList.size(); i++) {
directories[i] = arrayList.get(i);
}
return directories;
}
}
The MyLog.d is a trace class that expands Log.d - it can be dropped.
The class reads /proc/mounts/ and:
If all this is matched, it assumes that you have an sdcard and adds the path to the array list. It returns a string array of path names.
To call the getDirectories function, code something similar to:
String[] sdcardDirectories = GetRemoveableDevice.getDirectories();
The paths returned can be used to create a user selection list, scan for a file, or whatever.
Finally, here's two lines of MyLog.d from an emulator test (second line is the emulator sdcard):
09-19 15:57:12.511: D/GetRemoveableDevice(651): lineRead: /dev/block/mtdblock2 /cache yaffs2 rw,nosuid,nodev 0 0
09-19 15:57:12.511: D/GetRemoveableDevice(651): lineRead: /dev/block/vold/179:0 /mnt/sdcard vfat rw,dirsync,nosuid,nodev,noexec,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0
Based on Howards class I made some modifications to make it work on the Galaxy S3.
_
public static String getDirectory() {
Log.d(TAG, "getStorageDirectories");
File tempFile;
String[] splits;
ArrayList<String> arrayList = new ArrayList<String>();
BufferedReader bufferedReader = null;
String lineRead;
try {
arrayList.clear(); // redundant, but what the hey
bufferedReader = new BufferedReader(new FileReader("/proc/mounts"));
while ((lineRead = bufferedReader.readLine()) != null) {
Log.d(TAG, "lineRead: " + lineRead);
splits = lineRead.split(" ");
// skip if not external storage device
if (!splits[0].contains("/dev/block/")) {
continue;
}
// skip if mtdblock device
if (splits[0].contains("/dev/block/mtdblock")) {
continue;
}
// skip if not in vfat node
if (!splits[2].contains("vfat")) {
continue;
}
// skip these names
if (splits[1].contains("/secure")) {
continue;
}
if (splits[1].contains("/mnt/asec")) {
continue;
}
// Eliminate if not a directory or fully accessible
tempFile = new File(splits[1]);
if (!tempFile.exists()) {
continue;
}
if (!tempFile.isDirectory()) {
continue;
}
if (!tempFile.canRead()) {
continue;
}
if (!tempFile.canWrite()) {
continue;
}
// Met all the criteria, assume sdcard
return splits[1];
}
} catch (FileNotFoundException e) {
} catch (IOException e) {
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException e) {
}
}
}
return null;
}
Based on the 2 classes presented above I modified the class further on noticing that all of the external removable storage on several phones and tablets that I could find were mounted using vold, the volume mounting daemon.
// skip if not external storage device
if (!splits[0].contains("vold")) {
continue;
}
if (splits[1].contains("/mnt/asec")) {
continue;
}
// Eliminate if not a directory or fully accessible
tempFile = new File(splits[1]);
if (!tempFile.exists()) {
continue;
}
if (!tempFile.isDirectory()) {
continue;
}
if (!tempFile.canRead()) {
continue;
}
if (!tempFile.canWrite()) {
continue;
}
// Met all the criteria, assume sdcard
arrayList.add(splits[1]);
These capabilities are available in all Android versions:
To obtain the application's folder on the external storage, call Context.getExternalFilesDir
.
Keep in mind that your app needs explicit permission to access external storage, and that you should check if it is available via Environment.getExternalStorageState
And yes, ACTION_MEDIA_MOUNTED
will be broadcast whenever removable media becomes accessible (You should also listen for ACTION_MEDIA_EJECT
and ACTION_MEDIA_REMOVED
)
This is the method I created and am using. This has worked on Samsung Galaxy S4, Samsung Galaxy Note 3 and Sony Xperia Z2.
private static String[] getRemovableStoragePaths() {
String[] directories;
String[] splits;
ArrayList<String> pathList = new ArrayList<String>();
BufferedReader bufferedReader = null;
String lineRead;
try {
bufferedReader = new BufferedReader(new FileReader("/proc/mounts"));
while ((lineRead = bufferedReader.readLine()) != null) {
Log.d(TAG, "lineRead: " + lineRead);
splits = lineRead.split(" ");
Log.d(TAG, "Testing path: " + splits[1]);
if (!splits[1].contains("/storage")) {
continue;
}
if (splits[1].contains("/emulated")) {
// emulated indicates an internal storage location, so skip it.
continue;
}
// Eliminate if not a directory or fully accessible
Log.d(TAG, "Path found: " + splits[1]);
// Met all the criteria, assume sdcard
pathList.add(splits[1]);
}
} catch (FileNotFoundException e) {
} catch (IOException e) {
} finally {
if (bufferedReader != null) {
try {
bufferedReader.close();
} catch (IOException e) {
}
}
}
// Send list back to caller
if (pathList.size() == 0) {
pathList.add("sdcard not found");
} else {
Log.d(TAG, "Found potential removable storage locations: " + pathList);
}
directories = new String[pathList.size()];
for (int i = 0; i < pathList.size(); i++) {
directories[i] = pathList.get(i);
}
return directories;
}
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