Java: The Complete Reference, Eleventh Edition, 11th Edition

CHAPTER

20

java.util Part 2: More Utility Classes

This chapter continues our discussion of java.util by examining those classes and interfaces that are not part of the Collections Framework. These include classes that support timers, work with dates, compute random numbers, and bundle resources. Also covered are the Formatter and Scanner classes which make it easy to write and read formatted data, and the Optional class, which simplifies handling situations in which a value may be absent. Finally, the subpackages of java.util are summarized at the end of this chapter. Of particular interest is java.util.function, which defines several standard functional interfaces. One last point: the Observer interface and the Observable class packaged in ...