Java - Trimming trailing whitespace from a byte array

Question

I have byte arrays similar to this:

[77, 83, 65, 80, 79, 67, 32, 32, 32, 32, 32, 32, 32]

roughly equal to

[M , S, A, P, O, C,  ,  ,  ,  ,  ,  ,  ] when printed as chars.

Now I want to trim the trailing whitespace so it looks like:

[77, 83, 65, 80, 79, 67]

Easiest way to do this?

Edit: I don't want to deal with Strings because there is the possibility for non-printable bytes, and I can not afford to lose that data. It needs to be byte arrays :( Whenever I do convert to Strings, bytes like 01 (SOH) 02 (STX) etc are lost.

Edit 2: Just to clarify. DO I lose data if I convert byte arrays to Strings? Now a little confused. What about if the bytes are of a different character set?

Answer 1

Without converting to a string:

byte[] input = /* whatever */;
int i = input.length;
while (i-- > 0 && input[i] == 32) {}

byte[] output = new byte[i+1];
System.arraycopy(input, 0, output, 0, i+1);

---

Tests:

• [77, 83, 65, 80, 79, 67, 32, 32, 32, 32, 32, 32, 32] → [77, 83, 65, 80, 79, 67]
• [77, 83, 65, 80, 79, 67] → [77, 83, 65, 80, 79, 67]
• [32, 32, 32, 32, 32, 32, 32] → []
• [] → []
• [77, 83, 65, 80, 79, 67, 32, 32, 32, 32, 32, 32, 32, 80]
  → [77, 83, 65, 80, 79, 67, 32, 32, 32, 32, 32, 32, 32, 80]