In this chapter you'll be looking at some more very useful classes in the java.util package, but this time they are not collection classes—just a collection of classes. You will also be looking at the facilities provided by classes in the java.util.regex package that implement regular expressions in Java. Support for regular expressions is a very powerful and important feature of Java.
In this chapter you'll learn:
How to use the static methods in the Arrays class for filling, comparing, sorting, and searching arrays
How to use the Observable class and the Observer interface to communicate between objects
What facilities the Random class provides
How to create and use Date and Calendar objects
What regular expressions are and how you can create and use them
What a Scanner class does and how you use it