posted 16 years ago
I don't think that multiple GIFs in a single byte[] is a valid animated GIF; in fact, I'm sure it's not.
But to combine two arrays of any type, the recipe is the same: create a new array large enough to hold all the contents, then copy each component array into the new larger array.
byte[] b1 = ...
byte[] b2 = ...
byte[] all = new byte[b1.length + b2.length];
System.arraycopy(b1, 0, all, 0, b1.length);
System.arraycopy(b2, 0, all, b1.length, b2.length);