Question

I am writing a code in which i need filesize and filesize unit. Lets say if someone is calling my function he would call it
myfun (3, MB)

Which means the expected file size would be 3 MB. I am thinking to put this “file unit” in an enum

public enum SizeUnit {BYTE, KILOBYTE, MEGABYTE, GIGABYTE}

Now the problem is converting the the given size into bytes. Of course i can do simple math, but i want something more genering. so lets say if somene has called me function like

myfun (3, MEGABYTE)
in my code i want simply 3 * MEGABYTE to convert it into BYTE unit.

I am not sure if this is possible … I am just thinking about one possibility. There could be a method in enum, which takes the its unit and do the calculation? (i don’t want to do the trivial one, there should be something generic enough).

Answer 1

You can do something like this:

public enum SizeUnit
{
  BYTE(1),
  KILOBYTE(1024),
  ...;

  private final int bytes; 
  private SizeUnit(final int bytes) { this.bytes = bytes; }
  public int getByteCount() { return this.bytes; }
}

Then you can do things like:

3 * KILOBYTE.getByteCount();

or even define a method called getBytes which passes a number. So KILOBYTE.getBytes(3).