Get file list form sdcard folder in android

 String root_sd2 = Environment.getExternalStorageDirectory().toString();
            File file1 = new File( root_sd2 + "/Fodler name" ) ;      
            File list1[] = file1.listFiles();
            totalImages = list1.length;


OR
int totalImages = 0;
String root_sd = Environment.getExternalStorageDirectory().toString();
                File imglista = new File( root_sd + "/Folder NAme" ) ;      
                File imginfolder[] = imglista.listFiles();
                bitmap = BitmapFactory.decodeFile(imginfolder[totalImages ].getAbsolutePath());