Match Multiline Text Using Regular Expression
When attempting to match multiline text with Java, you may encounter challenges using the Pattern.MULTILINE modifier and the (?m) expression. Here's an example that explains the difference and provides a solution:
We have the following multiline text:
User Comments: This is \t a\ta \n test \n\n message \n
Pattern with Pattern.MULTILINE Modifier:
String pattern1 = "User Comments: (\W)*(\S)*"; Pattern p = Pattern.compile(pattern1, Pattern.MULTILINE); System.out.println(p.matcher(test).find()); // true
This pattern successfully matches the text because the Pattern.MULTILINE modifier allows the ^ and $ anchors to match at the start and end of each line.
Pattern with (?m) Expression:
String pattern2 = "(?m)User Comments: (\W)*(\S)*"; System.out.println(test.matches(pattern2)); // false
This pattern fails to match because the (?m) expression is incorrect. It should be (?s) to enable the DOTALL mode, which allows the dot (.) to match newline characters.
Furthermore, the matches() method is used to check if the entire string matches the pattern. In this case, the pattern only matches part of the string, so matches() returns false.
Solution:
To correctly match the multiline text using a regular expression, you can use the following pattern with the Pattern.DOTALL modifier:
Pattern regex = Pattern.compile("^\s*User Comments:\s+(.*)", Pattern.DOTALL); Matcher regexMatcher = regex.matcher(subjectString); if (regexMatcher.find()) { ResultString = regexMatcher.group(1); }
This pattern will capture the text after "User Comments:" and store it in ResultString.
The above is the detailed content of How Can I Correctly Match Multiline Text Using Java Regular Expressions?. For more information, please follow other related articles on the PHP Chinese website!

The article discusses using Maven and Gradle for Java project management, build automation, and dependency resolution, comparing their approaches and optimization strategies.

The article discusses creating and using custom Java libraries (JAR files) with proper versioning and dependency management, using tools like Maven and Gradle.

The article discusses implementing multi-level caching in Java using Caffeine and Guava Cache to enhance application performance. It covers setup, integration, and performance benefits, along with configuration and eviction policy management best pra

The article discusses using JPA for object-relational mapping with advanced features like caching and lazy loading. It covers setup, entity mapping, and best practices for optimizing performance while highlighting potential pitfalls.[159 characters]

Java's classloading involves loading, linking, and initializing classes using a hierarchical system with Bootstrap, Extension, and Application classloaders. The parent delegation model ensures core classes are loaded first, affecting custom class loa


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

ZendStudio 13.5.1 Mac
Powerful PHP integrated development environment

Zend Studio 13.0.1
Powerful PHP integrated development environment

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function

Safe Exam Browser
Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

Dreamweaver CS6
Visual web development tools