What is the most efficient way in Java to pack bits into byte[] and read it back?

Question

I currently use these two functions to pack and read bits in a byte array. Wondering if anybody has any better ideas or faster ways to do it?

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Answer 1

A totally different route would be to define static table of all possible combinations and perform a lookup instead of calculating results each time. I think thats how they do it in cryptography. array[i] x 3 should be much faster than numBits bitwise operations. It will occupy some heap though.