


Match Multiline Text Using Regular Expression
When attempting to match multiline text in Java, you may encounter differences in behavior between using the Pattern class with the Pattern.MULTILINE modifier and using the (?m) modifier.
To understand the discrepancy, it's crucial to grasp the purpose of these modifiers.
Pattern.MULTILINE and (?m)
Both Pattern.MULTILINE and (?m) are used to extend the behavior of regular expression anchors (^ and $) to match not only the start and end of the entire string but also the start and end of each line within the string.
Pattern.DOTALL and (?s)
However, the key difference between these modifiers lies in the handling of newline (carriage return) characters. Pattern.MULTILINE does not extend the matching ability of the dot (.) wildcard character to include newline characters. To include them, you must use Pattern.DOTALL or (?s).
Matching the Example String
In your example, the string contains multiple lines, and you want to find text that starts with "User Comments:". Using Pattern.MULTILINE alone will allow the anchors to match the start of each line, but the dot character will not match newlines.
To correctly match multiline text and capture the characters after "User Comments:", you should use Pattern.DOTALL or (?s) in conjunction with Pattern.MULTILINE or (?m):
Pattern regex = Pattern.compile("^\s*User Comments:\s+(.*)", Pattern.DOTALL); Matcher regexMatcher = regex.matcher(subjectString); if (regexMatcher.find()) { ResultString = regexMatcher.group(1); }
This regex will match the start of each line and will further capture all non-whitespace characters after "User Comments:".
The above is the detailed content of How Do `Pattern.MULTILINE` and `(?m)` Differ When Matching Multiline Text in Java Regular Expressions?. For more information, please follow other related articles on the PHP Chinese website!

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

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

This article explores integrating functional programming into Java using lambda expressions, Streams API, method references, and Optional. It highlights benefits like improved code readability and maintainability through conciseness and immutability

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]

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

This article explains Java's NIO API for non-blocking I/O, using Selectors and Channels to handle multiple connections efficiently with a single thread. It details the process, benefits (scalability, performance), and potential pitfalls (complexity,

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

This article details Java's socket API for network communication, covering client-server setup, data handling, and crucial considerations like resource management, error handling, and security. It also explores performance optimization techniques, i


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

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

MinGW - Minimalist GNU for Windows
This project is in the process of being migrated to osdn.net/projects/mingw, you can continue to follow us there. MinGW: A native Windows port of the GNU Compiler Collection (GCC), freely distributable import libraries and header files for building native Windows applications; includes extensions to the MSVC runtime to support C99 functionality. All MinGW software can run on 64-bit Windows platforms.

SublimeText3 English version
Recommended: Win version, supports code prompts!

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft