Analyzing code with the Maven PMD plugin

PMD is a source code analyzer. It finds common programming flaws such as unused variables, empty catch blocks, and unnecessary object creation. It also includes the Copy/Paste Detector (CPD) that finds duplicated code.

How to do it...

Use the following steps to run PMD on a Maven project:

1. Open the Maven project for which you want to do a PMD analysis (for instance, project-with-violations).

2. Run the following command:

   mvn pmd:pmd pmd:cpd
   

3. Observe the output:

   [INFO] --- maven-pmd-plugin:3.2:pmd (default-cli) @ project-with-violations ---
   [WARNING] Unable to locate Source XRef to link to – DISABLED
   [INFO] --- maven-pmd-plugin:3.2:cpd (default-cli) @ project-with-violations ---
   [WARNING] Unable to locate Source XRef to link to - DISABLED
   [INFO] ------------------------------------------------------------------------
   [INFO] BUILD SUCCESS
   

4. Check the contents of the target folder:

   

5. Open the pmd.xml report:

   

6. Open the cpd.html file in the site folder:

   

How it works...

The...