Converting Strings To Bits / Bytes And Vice Versa

I have:

Java Code: String s = "111100100111011011000010110011101"; mh_sh_highlight_all('java');

I am trying to convert that to bits/bytes.

I need to make that into a series of bits with the same exact values..."1" = a 1 bit, and "0" = a 0 bit.

Remarkably, I haven't been able to find much on this sort of conversion - possibly I am just not searching with the right keywords? As typically, stackexchange or other parts of the web have the same question that I have, asked (and answered) by many others.

How do I go about doing this?

Furthermore, how would I go about saving this to a file - and are there already good "kinds" of files to save this into. If not, how do I go about making my "own" type of "file."

CONTEXT:

I've written a compression system. To keep things simple, I've been using a string to hold the 1s and 0s, so that debugging is simpler, and overall, everything is easier to write. Now, however, my algorithm is finished - and I'm moving on to create a GUI and a working system. This is the last step that I need for the non-GUI stuff (which I'm writing through javafx by the way - is this the right thing to use? I've been told that that is where people are moving towards. Away from swing).