Hi,
I am a computer science master student at the university of Paderborn. I have quite some experience in developing java applications and I am familiar with computer architecture. A year ago I was tutoring the "fundamentals of computer architecture" lecture where we did exactly the stuff you have to do for your assignment (we didn't program it, but we worked with the 5 step pipeline for several weeks, working with "Computer Organization & Design – The Hardware / Software Interface" and the MIPS instruction set).
Therefore I think I can help you with this task and program the requested assembler simulator.