log4j-utils 🚀

log4j-utils is a collection of high-performance, community-driven plugins for Apache Log4j. This project provides "plug-and-play" extensions designed to solve common logging challenges—such as sensitive data masking and message transformation—without requiring custom Java code in every microservice.

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✨ Features

• Easy Configuration: Simplified programmatic setup for Log4j.
• Modern Java Support: Fully compatible with Java 8 through Java 21+.
• Checkstyle Verified: Follows Google Java Style for clean, maintainable code.
• Log4j Integration: Native support for Log4j Core version 2.24.3.

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🚀 Featured Plugin: MessageRewritePolicy

The MessageRewritePolicy allows you to scrub or transform log messages globally using configurable regex patterns directly in your log4j2.xml.

Key Benefits:

• Loosely Coupled: Decouples your masking logic from your application code.
• Easy Configuration: Update security policies (like masking new token formats) via XML without redeploying code.

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📦 Installation

Add the following dependency to your pom.xml:

<dependency>
    <groupId>in.org.nnm</groupId>
    <artifactId>log4j-utils</artifactId>
    <version>1.0.0</version>
</dependency>

For Gradle users:

implementation("in.org.nnm:log4j-utils:1.0.0")

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🛠 Usage

To use these utilities in your project, ensure you have the necessary Log4j dependencies configured.

Configuration example log4j2.xml

<Rewrite name="MASKING_REWRITE">
    <MessageRewritePolicy>
        <replace regex="([A-Za-z0-9._%+-])([A-Za-z0-9._%+-]*)(@[A-Za-z0-9.-]+\.[A-Za-z]{2,})"
                 replacement="[EMAIL]"/>
        <replace regex="\+?1?\s*\(?\d{3}\)?[\s.-]?\d{3}[\s.-]?\d{4}"
                 replacement="[PHONE]"/>
        <replace> <!-- Uses a CDATA Section -->
            <regex><![CDATA[[A-Za-z0-9_%+-]{20,}\.[A-Za-z0-9_%+-]{20,}\.[A-Za-z0-9_%+-]+\b]]></regex>
            <replacement>[TOKEN]</replacement>
        </replace>
    </MessageRewritePolicy>
    <Appender-Ref ref="Console"/>
</Rewrite>

Configuration example log4j2.yml

rewrite:
  - name: MASKING_REWRITE
    MessageRewritePolicy:
      replace:
        - regex: "([A-Za-z0-9._%+-])([A-Za-z0-9._%+-]*)(@[A-Za-z0-9.-]+\\.[A-Za-z]{2,})"
          replacement: "[EMAIL MASKED]"
        - regex: "\\+?1?\\s*\\(?\\d{3}\\)?[\\s.-]?\\d{3}[\\s.-]?\\d{4}"
          replacement: "[PHONE]"
        - regex: "[A-Za-z0-9_%+-]{20,}\\.[A-Za-z0-9_%+-]{20,}\\.[A-Za-z0-9_%+-]+\\b"
          replacement: "[TOKEN]"
    AppenderRef:
      - ref: Console

👉 log4j configuration files : Log4j Configuration Examples

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🚀 Demo Project

To see log4j-utils in action within a Spring Boot/Java environment, check out the demo implementation:

• Repository: logging-activity

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🤝 Contributing

Contributions are welcome! If you have a Log4j plugin that solves a common problem, feel free to:

• open an issue
• Fork the repository.
• Create a feature branch.
• Submit a Pull Request.

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📬 Contact & Support

Developed by Neelesh Mehar

• Website: nnm.org.in
• GitHub: @Neel1210

Special thanks to the Apache Log4j Maintainers for their guidance on this project.