PMD: A Comprehensive Guide to Static Code Analysis

PMD is a robust, extensible static code analyzer that supports multiple programming languages. It is designed to identify common programming flaws such as unused variables, empty catch blocks, and unnecessary object creation. Primarily focused on Java and Apex, PMD also supports 16 other languages, making it a versatile tool for developers.

Key Features

• Multi-language Support: PMD supports Java, JavaScript, Salesforce.com Apex and Visualforce, Kotlin, Swift, Modelica, PLSQL, Apache Velocity, JSP, WSDL, Maven POM, HTML, XML, and XSL. Although Scala is supported, there are currently no specific rules for it.
• Extensive Rule Set: With over 400 built-in rules, PMD provides a comprehensive set of checks for various programming languages. Users can also extend PMD with custom rules written in Java or using XPath queries.
• Copy-Paste Detector (CPD): This feature helps identify duplicated code across a wide range of languages including Java, C/C++, Python, and more.
• Integration with Development Tools: PMD integrates seamlessly with popular development environments such as Eclipse, IntelliJ IDEA, and NetBeans, as well as build tools like Maven and Gradle.

Installation and Setup

To get started with PMD, follow these steps:

1. Download: Obtain the latest version of PMD from the .
2. Installation: Unzip the downloaded file and set up an alias for easy command-line access:

   $ cd $HOME
   $ wget https://github.com/pmd/pmd/releases/download/pmd_releases%2F7.6.0/pmd-dist-7.6.0-bin.zip
   $ unzip pmd-dist-7.6.0-bin.zip
   $ alias pmd="$HOME/pmd-bin-7.6.0/bin/pmd"
   

3. Running PMD: Execute PMD with a simple command to check your source code:

   $ pmd check -d /usr/src -R rulesets/java/quickstart.xml -f text
   

Pricing

PMD is open-source and free to use, distributed under a BSD-style license. This makes it an attractive option for both individual developers and organizations.

Tips for Effective Use

• Customize Rules: Tailor PMD to your project's needs by writing custom rules in Java or using XPath.
• Regular Analysis: Integrate PMD into your CI/CD pipeline to ensure continuous code quality checks.
• Explore Plugins: Utilize PMD plugins for IDEs and build tools to streamline your development workflow.

Comparison with Other Tools

While tools like SonarQube and Checkstyle also offer static code analysis, PMD stands out with its extensive language support and customizable rule set. Its CPD feature is particularly useful for detecting code duplication across different languages.

Frequently Asked Questions

Q: Can PMD be used for languages other than Java? A: Yes, PMD supports a wide range of languages including JavaScript, Apex, Kotlin, and more.

Q: How can I contribute to PMD? A: PMD is open-source, and contributions are welcome. You can check out the source code on GitHub and follow the contribution guidelines.

Get Started with PMD

Ready to improve your code quality? Download PMD today and integrate it into your development process to catch common programming errors early and maintain high-quality code standards.