Chapter 9. Handling Common Data Formats
Most of programming is handling data in various formats. In this chapter, we will introduce Java’s support for handling two big classes of data—text and numbers. The second half of the chapter will focus on handling date and time information. This is of particular interest, as Java 8 shipped a completely new API for handling date and time. We cover this interface in some depth before finishing the chapter by briefly discussing Java’s original date and time API.
Many applications are still using the legacy APIs, so developers need to be aware of the old way of doing things, but the new APIs are so much better that we recommend converting as soon as possible. Before we get to those more complex formats, let’s get under way by talking about textual data and strings.
Text
We have already met Java’s strings on many occasions. They consist of
sequences of Unicode characters and are represented as instances of
the String
class. Strings are one of the most common types of data
that Java programs process (a claim you can investigate for yourself by
using the jmap
tool that we’ll meet in Chapter 13).
In this section, we’ll meet the String
class in some more depth and
understand why it is in a rather unique position within the Java
language. Later in the section, we’ll introduce regular expressions, a
very common abstraction for searching text for patterns (and a classic
tool in the programmer’s arsenal, regardless of language).
Special Syntax for ...
Get Java in a Nutshell, 8th Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.