Regular Expressions and Other Packages

CHAPTER 30

Regular Expressions and Other Packages

When Java was originally released, it included a set of eight packages, called the core API. Each subsequent release added to the API. Today, the Java API contains a very large number of packages. Many of the packages support areas of specialization that are beyond the scope of this book. However, several packages warrant an examination here. Four are java.util.regex, java.lang.reflect, java.rmi, and java.text. They support regular expression processing, reflection, Remote Method Invocation (RMI), and text formatting, respectively. The chapter ends by introducing the new date and time API in java.time and its subpackages.

The regular expression package lets you perform sophisticated pattern matching operations. This chapter provides an in-depth introduction to this package along with extensive examples. Reflection is the ability of software to analyze itself. It is an essential part of the Java Beans technology that is covered in Chapter 37. Remote Method Invocation (RMI) allows you to build Java applications that are distributed among several machines. This chapter provides a simple client/server example that uses RMI. The text formatting capabilities of java.text have many uses. The one examined here formats date and time strings. The new date and time API supplies an up-to-date approach to handling date and time.