noob question java

I need to be able to recognize various types of inputs as a "yes" response like y,Yes,YES, etc.. what would be a good place to read up on this and figure out the answer. Is there a string method that can do this simply (like maybe String.equalsIgnoreCase(another yes string))?

So I began reading the book you guys are always talking about, "SICP". As I already know C quite well, the beginning of the first chapter was quite boring. But when I came to the part about procedures, a light suddenly switched on in my brain. The lot of annoying parenthesis became a beautiful tree of procedures. I began to see the data flowing perfectly through it's nodes, being processed again and again until they merge and reach the final point of their existance : the top node of the tree.
 
Later this day, I was getting drunk with some friends. Then came the usual drunk talk about the meaning of life with low-level philosophy. When I was asked my opinion on the subject, I answered that the Universe is a giant list, and the meaning of life is to discover the first operator of this list. They stared at me and an awkward silence followed.
 
What's happening to me, /prog/ ?