Have in mind though, that getExternalStorageDirectory() is not going to work properly on some phones e.g. my Motorola razr maxx, as it has 2 cards /mnt/sdcard and /mnt/sdcard-ext - for internal and external SD cards respectfully. You will be getting the /mnt/sdcard only reply every time. Google must provide a way to deal with such a situation. As it renders many SD card aware apps (i.e card backup) failing miserably on these phones.
As described in Documentation Environment.getExternalStorageDirectory() :
Environment.getExternalStorageDirectory() Return the primary shared/external storage directory.
This is an example of how to use it reading an image :
String fileName = "stored_image.jpg";
String baseDir = Environment.getExternalStorageDirectory().getAbsolutePath();
String pathDir = baseDir + "/Android/data/com.mypackage.myapplication/";
File f = new File(pathDir + File.separator + fileName);
if(f.exists()){
Log.d("Application", "The file " + file.getName() + " exists!";
}else{
Log.d("Application", "The file no longer exists!";
}
To get the directory, you can use the code below:
File cacheDir = new File(Environment.getExternalStorageDirectory() + File.separator + "");
Source: Stackoverflow.com