String is very important data structure and that's why its also very popular on programming interview. Here is a list of top 20 String related coding questions to solve over weekend. If you want to do well on Data Structure and Algorithm interview, you must have good understanding of String based algorithm question.
Fork Join framework is new addition in Java 7 which is earlier available as separate JSR. fork join framework allows you to take full benefit of multiple cores of machine and can be used to implement map reduce algorithm in Java.