文件大小Byte转化为KB、MB、GB等

/**
* 将文件大小由Byte转为MB或者KB
* @return
*/
private String fileSizeByteToM(Long size) {

BigDecimal fileSize = new BigDecimal(size);
BigDecimal param = new BigDecimal(1024);
int count = 0;
while(fileSize.compareTo(param) > 0 && count < 5)
{
fileSize = fileSize.divide(param);
count++;
}
DecimalFormat df = new DecimalFormat("#.##");
String result = df.format(fileSize) + "";
switch (count) {
case 0:
result += "B";
break;
case 1:
result += "KB";
break;
case 2:
result += "MB";
break;
case 3:
result += "GB";
break;
case 4:
result += "TB";
break;
case 5:
result += "PB";
break;
}
return result;
}