Util class for check available free space in internal/external memory

MemoryUtils.java

import android.os.Build;
import android.os.Environment;
import android.os.StatFs;

import java.io.File;


public class MemoryUtils {

    public final static int MIN_SIZE_MB = 100;
    public final static int MAX_SIZE_MB = 300;

    static final int ERROR = -1;

    public static boolean externalMemoryAvailable() {
        return android.os.Environment.getExternalStorageState().equals(
                android.os.Environment.MEDIA_MOUNTED);
    }

    /**
     * get available memory in MB in external storage if exists
     *
     * @return free space in MB, if external storage not exists, returns -1
     */
    public static long getAvailableExternalMemorySize() {
        if (externalMemoryAvailable()) {
            File path = Environment.getExternalStorageDirectory();
            StatFs stat = new StatFs(path.getPath());
            long blockSize = getBlockSize(stat);
            long availableBlocks = getBlockCount(stat);
            return (availableBlocks * blockSize)
                    / (1024 * 1024);
        } else {
            return ERROR;
        }
    }

    static public long getTotalExternalMemorySize() {
        if (externalMemoryAvailable()) {
            File path = Environment.getExternalStorageDirectory();
            StatFs stat = new StatFs(path.getPath());
            long blockSize = getBlockSize(stat);
            long totalBlocks = getBlockCount(stat);
            return totalBlocks * blockSize;
        } else {
            return ERROR;
        }
    }

    public static StatFs getInternalStatFs() {
        File path = Environment.getDataDirectory();
        return new StatFs(path.getPath());
    }

    public static StatFs getExternalStatFs() {
        File path = Environment.getExternalStorageDirectory();
        return new StatFs(path.getPath());
    }

    public static long getAvailableInternalMemorySize(StatFs stat) {
        long blockSize = getBlockSize(stat);
        long availableBlocks = getBlockCount(stat);
        return availableBlocks * blockSize;
    }

    public static long getTotalInternalMemorySize(StatFs stat) {
        long blockSize = getBlockSize(stat);
        long totalBlocks = getBlockCount(stat);
        return totalBlocks * blockSize;
    }

    private static long getBlockSize(StatFs stat) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
            return stat.getBlockSizeLong();
        } else {
            return stat.getBlockSize();
        }
    }

    private static long getBlockCount(StatFs stat) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
            return stat.getBlockCountLong();
        } else {
            return stat.getBlockCount();
        }
    }

    public static String formatSize(long size) {
        String suffix = null;

        if (size >= 1024) {
            suffix = "KB";
            size /= 1024;
            if (size >= 1024) {
                suffix = "MB";
                size /= 1024;
            }
        }

        StringBuilder resultBuffer = new StringBuilder(Long.toString(size));

        int commaOffset = resultBuffer.length() - 3;
        while (commaOffset > 0) {
            resultBuffer.insert(commaOffset, ',');
            commaOffset -= 3;
        }

        if (suffix != null) resultBuffer.append(suffix);
        return resultBuffer.toString();
    }
}