PMD自定义规则集-也许您拼错了规则名称？

Question

I am trying to integrate pmd into my project. But I am getting following error

java.lang.IllegalArgumentException: No rules found. Maybe you mispelled a rule name?

The pom.xml entry is as follows -

<reporting>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-pmd-plugin</artifactId>
            <version>3.7</version>
            <configuration>
                <linkXRef>false</linkXRef>
                <rulesets>             
                    <ruleset>
                        pmdruleset.xml
                    </ruleset>
                </rulesets>
            </configuration>
        </plugin>
    </plugins>
</reporting>

The custom rule set file contains following -

<?xml version="1.0"?>
<ruleset name="Controversial"
         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>
        <rule ref="rulesets/java/errorprone.xml/NullAssignment"/>
    </description>
</ruleset>

I am unable to understand what is wrong. Can someone help!

Answer 1

@eclipse-pmd is right, the rule tag needs to be a child of the ruleset tag.

Additionally, the rule you are trying to use (NullAssignment), is not in the ruleset errorprone, but in controversial. With PMD 6, the rules have additionally been organized into categories and is now in category "errorprone". More on this will follow.

maven-pmd-plugin 3.7 / PMD 5.5.1

You are using maven-pmd-plugin version 3.7 -> this means, you automatically use an old PMD version (version 5.5.1 to be precise). For this version, your ruleset should look like the following:

<?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>
        Custom Ruleset
    </description>

    <rule ref="rulesets/java/controversial.xml/NullAssignment"/>
</ruleset>

Documentation for PMD 5.5.1 is available at: https://pmd.github.io/pmd-5.5.1/pmd-java/rules/java/controversial.html#NullAssignment

maven-pmd-plugin 3.9.0 / PMD 6.0.1

If you switch to the latest maven-pmd-plugin version 3.9.0, you'll automatically use PMD 6.0.1 and benefit from the latest bugfixes. You can continue to use the ruleset from above, however you'll see a deprecation notice, since we moved the rule. To get rid of this warning, use the following rule reference:

<rule ref="category/java/errorprone.xml/NullAssignment" />

Documentation for PMD 6.0.1 is available at: https://pmd.github.io/pmd-6.0.1/pmd_rules_java_errorprone.html#nullassignment

Documentation about rulesets is here: https://pmd.github.io/pmd-6.0.1/pmd_userdocs_understanding_rulesets.html