This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
perhaps one of the best ways to search a string for a specific pattern without using regular expression is the Knuth-Morris-Pratt algorithm. It's to complicated to explain here in a few lines but I'm sure you'll find lots of information about it in the internet. Good luck ;-)