Book Image

Java 9 Regular Expressions

By : Anubhava Srivastava
Book Image

Java 9 Regular Expressions

By: Anubhava Srivastava

Overview of this book

Regular expressions are a powerful tool in the programmer's toolbox and allow pattern matching. They are also used for manipulating text and data. This book will provide you with the know-how (and practical examples) to solve real-world problems using regex in Java. You will begin by discovering what regular expressions are and how they work with Java. This easy-to-follow guide is a great place from which to familiarize yourself with the core concepts of regular expressions and to master its implementation with the features of Java 9. You will learn how to match, extract, and transform text by matching specific words, characters, and patterns. You will learn when and where to apply the methods for finding patterns in digits, letters, Unicode characters, and string literals. Going forward, you will learn to use zero-length assertions and lookarounds, parsing the source code, and processing the log files. Finally, you will master tips, tricks, and best practices in regex with Java.
Table of Contents (15 chapters)
Title page
About the Author
About the Reviewer
Customer Feedback
Free Chapter
Getting Started with Regular Expressions

Chapter 5. Introduction to Java Regular Expression APIs - Pattern and Matcher Classes

In this chapter, we will introduce you to dedicated Java APIs for writing programs using regular expressions. Java provides a package, java.util.regex, which contains all the classes and interfaces for handling regular expressions. This package is in the java.base module, so we do not explicitly declare its use in the source file. The java.base module is automatically required by all modules, and it contains the most important and basic JDK packages and classes. Regular expressions is such an important topic and tool that Java 9 experts decided to keep it inside the java.base module.

We will cover the following classes and interfaces from this package:

  • The MatchResult interface
  • Using Pattern class
  • Using Matcher class
  • Various methods of Pattern and Matcher classes and how to use them for solving problems involving regular expressions