Pad a binary String equal to zero ("0") with leading zeros in Java

Question

Integer.toBinaryString(data)

gives me a binary String representation of my array data.

However I would like a simple way to add leading zeros to it, since a byte array equal to zero gives me a "0" String.

I'd like a one-liner like this:

String dataStr = Integer.toBinaryString(data).equals("0") ? String.format(format, Integer.toBinaryString(data)) : Integer.toBinaryString(data);

Is String.format() the correct approach? If yes, what format String should I use? Thanks in advance!

Edit: The data array is of dynamic length, so should the number of leading zeros.

Answer 1

For padding with, say, 5 leading zeroes, this will work:

String.format("%5s", Integer.toBinaryString(data)).replace(' ', '0');

You didn't specify the expected length of the string, in the sample code above I used 5, replace it with the proper value.

EDIT

I just noticed the comments. Sure you can build the pattern dynamically, but at some point you have to know the maximum expected size, depending on your problem, you'll know how to determine the value:

String formatPattern = "%" + maximumExpectedSize + "s";