Getting SD card directory and memory information

    /**
     * Returns the file object that contains SD card directory
     *
     * @return SD card directory as a file, null if the card is not mounted or unavailble
     */
    public File getSDCardDirectory() {
        File d = null;
        String storagePath = "/storage";
        StringBuilder sb = new StringBuilder();
        boolean isFirst = true;
        try {
            //we need to read the /proc/mounts file
            FileInputStream fs = new FileInputStream("/proc/mounts");
 
            DataInputStream in = new DataInputStream(fs);
            BufferedReader br = new BufferedReader(new InputStreamReader(in));
            String fileLine;
            //reading the file and separting each line by line separator
            while ((fileLine = br.readLine()) != null) {
                if (fileLine.contains(storagePath)) {
                    if (isFirst) {
                        isFirst = false;
                    } else {
                        sb.append("\n");
                    }
                    sb.append(fileLine);
                }
            }
            in.close(); //Close the stream
 
        } catch (Exception e) {
            //not doing anything
            Log.e("tag-ex",""+e.getLocalizedMessage());
        }
 
        //now we need to parse the file to get the SD card directory
        if (null != sb.toString() && !sb.toString().equals("")) {
            //putting all the storage directories in an array
            String sPathArray[] = sb.toString().split("\n");
            String sPath = "";
 
            if (sPathArray.length > 1) {
                // most of the case the second one is the SD card directory
                sPath = sPathArray[1];
                // if the directory is emulated then it is not SD card, we shall seek
                if (sPath.contains("emulated") && sPathArray.length > 2) {
                    sPath = sPathArray[2];
                }
            }
            //final filter, emulated and tmpfs not considered as SD card
            if (!sPath.equals("") && !sPath.contains("emulated") && !sPath.contains("tmpfs")) {
                //now we need the column that contains the directory
                sPath = sPath.substring(sPath.indexOf(storagePath), sPath.indexOf(" ", sPath.indexOf(storagePath)));
                d = new File(sPath);
            }
 
        }
 
        return d;
    }

    /**
     * Returns the available external memory size
     */
    public double getAvailableSDCardMemorySize() {
        File path = getSDCardDirectory();
        if (null != path) {//check if SD card is mounted
            StatFs stat = new StatFs(path.getPath());
            long blockSize = 0;
            if (Build.VERSION.SDK_INT < 18) {
                blockSize = stat.getBlockSize();
            } else {
                blockSize = stat.getBlockSizeLong();
            }
            long availableBlocks = 0;
            if (Build.VERSION.SDK_INT < 18) {
                availableBlocks = stat.getAvailableBlocks();
            } else {
                availableBlocks = stat.getAvailableBlocksLong();
            }
            return formatSizeGB(availableBlocks * blockSize);
        } else {
            return 0;
        }
    }
 
    /**
     * Returns the total external memory size
     */
    public double getTotalSDCardMemorySize() {
        File path = getSDCardDirectory();
        if (null != path) {//check if SD card is mounted
            StatFs stat = new StatFs(path.getPath());
            long blockSize = 0;
            if (Build.VERSION.SDK_INT < 18) {
                blockSize = stat.getBlockSize();
            } else {
                blockSize = stat.getBlockSizeLong();
            }
            long totalBlocks = 0;
            if (Build.VERSION.SDK_INT < 18) {
                totalBlocks = stat.getBlockCount();
            } else {
                totalBlocks = stat.getBlockCountLong();
            }
            return formatSizeGB(totalBlocks * blockSize);
        } else {
            return 0;
        }
    }
 
    private double gbDivider = 1073741824; //1 GB = 1073741824 Bytes
    /**
     * Returns the string formatted value for the size
     */
    public double formatSizeGB(double total) {
        double amount = (total / gbDivider);
        BigDecimal bd = new BigDecimal(amount).setScale(2, RoundingMode.HALF_EVEN);
        amount = bd.doubleValue();
        return amount;
    }