Key FeaturesDiscover regular expressions and how they workImplement regular expressions with Java to your code baseLearn to use regular expressions in emails, URLs, paths, and IP addressesBook DescriptionRegular expressions are a powerful tool in the programmers 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.What you will learnUnderstand the semantics, rules, and core concepts of writing Java code involving regular expressionsLearn about the java.util.Regex package using the Pattern class, Matcher class, code snippets, and moreMatch and capture text in regex and use back-references to the captured groupsExplore Regex using Java String methods and regex capabilities in the Java Scanner APIUse zero-width assertions and lookarounds in regexTest and optimize a poorly performing regex and various other performance tipsAbout the AuthorAnubhava Srivastava has more than 22 years of professional experience in architecture, design, and software development. He specializes mainly in the J2EE technology stack, web technologies, CICD, test-driven development, and AWS cloud-based development.He is an active contributor to the Stack Overflow community. He currently stands in the top 35 users in terms of reputations out of the 7.5 million Stack Overflow users. He is passionate about regular expressions and is always willing to sharpen his regex skills further. He has answered close to 10,000 regex questions on Stack Overflow.He has authored and released a test-driven framework, called GenericFixture, for FitNesse as an open source software.You can follow him on Twitter at @anubhava.Table of ContentsGetting Started with Regular ExpressionsUnderstanding the Core Constructs of Java Regular ExpressionsWorking with Groups, Capturing, and ReferencesRegular Expression Programming Using Java String and Scanner APIsIntroduction to Java Regular Expression APIs - Pattern and Matcher ClassesExploring Zero-width Assertions, Lookarounds, and Atomic GroupsUnderstanding the Union, Intersection, and Subtraction of Character ClassesRegular Expression Pitfalls, Optimization, and Performance Improvements