Java is one of the best languages for cross platform programming and because it is very simple to learn. You should have no problem picking it up with your prior experience. I am still an undergraduate CS but I have talked with many graduates newly coming into the market and most of the current jobs require at least 5 year minimal java experience, and other scripting languages. In fact most business companies program in Java. I guess it depends what you are wanting to program. Check out Y. Daniel Liang's Introduction to Java book. Can pick it up for about $100.