Java Utililty Methods Size Format

String format(long size)
format

DecimalFormat df = new DecimalFormat("0.00");
float sizeK = 1024.0f;
float sizeM = sizeK * sizeK;
float sizeG = sizeM * sizeK;
float sizeT = sizeG * sizeK;
if (size < sizeM) {
 return df.format(size / sizeK) + " KB";
if (size < sizeG) {
 return df.format(size / sizeM) + " MB";
if (size < sizeT) {
 return df.format(size / sizeG) + " GB";
return "";

String formatBinarySize(final long l)
Formats a binary size.

if ((l & -l) != l)
 throw new IllegalArgumentException("Not a power of 2: " + l);
if (l >= (1L << 40))
 return format(l >> 40) + "Ti";
if (l >= (1L << 30))
 return format(l >> 30) + "Gi";
if (l >= (1L << 20))
 return format(l >> 20) + "Mi";
...

String formatBytes(double size)
format Bytes

double k = size / 1024.0;
double m = k / 1024.0;
double g = m / 1024.0;
DecimalFormat dec = new DecimalFormat("0");
if (g > 1) {
 return dec.format(g).concat("G");
} else if (m > 1) {
 return dec.format(m).concat("M");
...

String formatBytes(long size)
Displays the given in a human-readable format.

if (size <= 0) {
 return size + " B"; 
String[] units = new String[] { "B", "KB", "MB", "GB", "TB" }; 
int digitGroups = (int) (Math.log10(size) / Math.log10(1024));
return new DecimalFormat("#,##0.#").format(size / Math.pow(1024, digitGroups)) + " " + units[digitGroups]; 

String formatByteSize(long bytes)
Returns a formatted string using an appropriate unit (Bytes, KB or MB).

if (bytes < 1024) {
 return numberFormat.format(bytes) + " Bytes";
float kb = (float) bytes / 1024;
if (kb < 1024) {
 return numberFormat.format(kb) + " KB";
float mb = kb / 1024;
...

String formatDataSize(final double dataSize)
Formats the specified data size in human readable format.

final NumberFormat format = NumberFormat.getNumberInstance();
format.setMaximumFractionDigits(2);
double dataSizeToFormat = dataSize / BYTES_IN_TERABYTE;
if (dataSizeToFormat > 1) {
 return format.format(dataSizeToFormat) + " TB";
dataSizeToFormat = dataSize / BYTES_IN_GIGABYTE;
if (dataSizeToFormat > 1) {
...

String formatDataSize(long bytes)
format Data Size

if (bytes <= 0)
 return "0 B";
final String[] units = new String[] { "B", "KB", "MB", "GB", "TB" };
int digits = (int) (Math.log(bytes) / Math.log(1024));
return new DecimalFormat("#,##0.##").format(bytes / Math.pow(1024, digits)) + " " + units[digits];

String formatDecimal(double size)
Format decimal numbers to #.##

DecimalFormat df = new DecimalFormat("#.###");
df.setRoundingMode(RoundingMode.CEILING);
return df.format(size);

String formatDiskSize(final long diskSize)
format Disk Size

final float COUNT = 1000;
if (diskSize < 1) {
 return "n/a";
if (diskSize == 0) {
 return "0";
final NumberFormat nf = NumberFormat.getInstance();
...

String formatFileSize(double fileSize, int precision, int unit, boolean showUnit)
Returns the file size.

String s = "#,";
for (int i = 0; i < precision; i++)
 s += "#";
DecimalFormat df = new DecimalFormat(s);
return applyDecimalFormat((long) fileSize, unit, df, showUnit);