java - Divide byte into two smaller numbers -

like in topic. writing application must save ram possible. want split byte 2 parts 4 bits each (numbers 0 15) - how can save , later read values?

if want store 2 numbers (range 0-15) in 1 byte, here's example on how save , restore them. note have make sure original numbers within allowed range, otherwise not work.

    // store both numbers in 1 byte     byte firstnumber = 10;     byte secondnumber = 15;     final byte bothnumbers = (byte) ((firstnumber << 4) | secondnumber);      // retreive original numbers     firstnumber = (byte) ((bothnumbers >> 4) & (byte) 0x0f);     secondnumber = (byte) (bothnumbers & 0x0f); 

also worth noting if want save memory possible shouldn't using java start with. jvm consumes memory itself. native languages more suited requirement.