<?xml version="1.0"?>
<ruleset name="Custom ruleset"
        xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 http://pmd.sourceforge.net/ruleset_2_0_0.xsd">
    <description>
        The default ruleset
    </description>
    <rule ref="rulesets/java/strings.xml"/>
    <rule ref="rulesets/java/unusedcode.xml"/>
</ruleset>

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-pmd-plugin</artifactId>
    <version>3.8</version>
    <executions>
        <execution>
            <id>pmd-check</id>
            <phase>validate</phase>
            <goals>
                <goal>check</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <printFailingErrors>true</printFailingErrors>
        <detail>true</detail>
        <rulesets>
            <ruleset>${basedir}/src/main/resources/ruleset.xml</ruleset>
        </rulesets>
    </configuration>
</plugin>

"PMD.UnusedFormalParameter"