Lesson: Regular Expressions

This lesson explains how to use the java.util.regex API for pattern matching with regular expressions. Although the syntax accepted by this package is similar to the Perl programming language, knowledge of Perl is not a prerequisite. This lesson starts with the basics, and gradually builds to cover more advanced techniques.

Introduction

Provides a general overview of regular expressions. It also introduces the core classes that comprise this API.

Test Harness

Defines a simple application for testing pattern matching with regular expressions.

String Literals

Introduces basic pattern matching, metacharacters, and quoting.

Character Classes

Describes simple character classes, negation, ranges, unions, intersections, and subtraction.

Predefined Character Classes

Describes the basic predefined character classes for whitespace, word, and digit characters.

Quantifiers

Explains greedy, reluctant, and possessive quantifiers for matching a specified expression x number of times.

Capturing Groups

Explains how to treat multiple characters as a single unit.

Boundary Matchers

Describes line, word, and input boundaries.

Methods of the Pattern Class

Examines other useful methods of the Pattern class, and explores advanced features such as compiling with flags and using embedded flag expressions.

Methods of the Matcher Class

Describes the commonly-used methods of the Matcher class.

Methods of the PatternSyntaxException Class

Describes how to examine a PatternSyntaxException.

Additional Resources

To read more about regular expressions, consult this section for additional resources.