Maven Plugin Configuration

---
name: maven-plugin-configuration
description: Use when configuring Maven plugins, setting up common plugins like compiler, surefire, jar, or creating custom plugin executions.
---

# Maven Plugin Configuration

Master Maven plugin configuration including core plugins, build plugins, reporting plugins, and custom plugin development.

## Overview

Maven plugins provide the actual functionality for building projects. Understanding how to configure plugins effectively is essential for customizing builds, optimizing performance, and ensuring code quality.

## Plugin Basics

### Plugin Structure

```xml
<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.12.1</version>
            <configuration>
                <!-- Plugin-specific configuration -->
            </configuration>
            <executions>
                <execution>
                    <id>compile-java</id>
                    <phase>compile</phase>
                    <goals>
                        <goal>compile</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>
```

### Plugin Management

```xml
<build>
    <pluginManagement>
        <plugins>
            <!-- Define versions and shared config -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.12.1</version>
                <configuration>
                    <release>17</release>
                </configuration>
            </plugin>
        </plugins>
    </pluginManagement>
    <plugins>
        <!-- Actually use plugin (inherits config) -->
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
        </plugin>
    </plugins>
</build>
```

## Core Build Plugins

### Compiler Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.12.1</version>
    <configuration>
        <release>17</release>
        <encoding>UTF-8</encoding>
        <showWarnings>true</showWarnings>
        <showDeprecation>true</showDeprecation>
        <compilerArgs>
            <arg>-Xlint:all</arg>
            <arg>-parameters</arg>
        </compilerArgs>
        <annotationProcessorPaths>
            <path>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>1.18.30</version>
            </path>
        </annotationProcessorPaths>
    </configuration>
</plugin>
```

### Resources Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-resources-plugin</artifactId>
    <version>3.3.1</version>
    <configuration>
        <encoding>UTF-8</encoding>
        <propertiesEncoding>UTF-8</propertiesEncoding>
        <nonFilteredFileExtensions>
            <nonFilteredFileExtension>pdf</nonFilteredFileExtension>
            <nonFilteredFileExtension>ico</nonFilteredFileExtension>
            <nonFilteredFileExtension>png</nonFilteredFileExtension>
            <nonFilteredFileExtension>jpg</nonFilteredFileExtension>
        </nonFilteredFileExtensions>
    </configuration>
</plugin>
```

### JAR Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-jar-plugin</artifactId>
    <version>3.3.0</version>
    <configuration>
        <archive>
            <manifest>
                <addClasspath>true</addClasspath>
                <mainClass>com.example.Main</mainClass>
                <addDefaultImplementationEntries>true</addDefaultImplementationEntries>
                <addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
            </manifest>
            <manifestEntries>
                <Build-Time>${maven.build.timestamp}</Build-Time>
                <Built-By>${user.name}</Built-By>
            </manifestEntries>
        </archive>
        <excludes>
            <exclude>**/logback-test.xml</exclude>
        </excludes>
    </configuration>
    <executions>
        <execution>
            <id>test-jar</id>
            <goals>
                <goal>test-jar</goal>
            </goals>
        </execution>
    </executions>
</plugin>
```

### Source Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-source-plugin</artifactId>
    <version>3.3.0</version>
    <executions>
        <execution>
            <id>attach-sources</id>
            <goals>
                <goal>jar-no-fork</goal>
            </goals>
        </execution>
    </executions>
</plugin>
```

### Javadoc Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-javadoc-plugin</artifactId>
    <version>3.6.3</version>
    <configuration>
        <doclint>none</doclint>
        <source>17</source>
        <quiet>true</quiet>
        <links>
            <link>https://docs.oracle.com/en/java/javase/17/docs/api/</link>
        </links>
    </configuration>
    <executions>
        <execution>
            <id>attach-javadocs</id>
            <goals>
                <goal>jar</goal>
            </goals>
        </execution>
    </executions>
</plugin>
```

## Testing Plugins

### Surefire Plugin (Unit Tests)

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-surefire-plugin</artifactId>
    <version>3.2.3</version>
    <configuration>
        <includes>
            <include>**/*Test.java</include>
            <include>**/*Tests.java</include>
            <include>**/Test*.java</include>
        </includes>
        <excludes>
            <exclude>**/*IT.java</exclude>
            <exclude>**/*IntegrationTest.java</exclude>
        </excludes>
        <argLine>-Xmx1024m -XX:+UseG1GC</argLine>
        <parallel>methods</parallel>
        <threadCount>4</threadCount>
        <forkCount>1C</forkCount>
        <reuseForks>true</reuseForks>
        <systemPropertyVariables>
            <spring.profiles.active>test</spring.profiles.active>
        </systemPropertyVariables>
        <environmentVariables>
            <TEST_ENV>true</TEST_ENV>
        </environmentVariables>
    </configuration>
</plugin>
```

### Failsafe Plugin (Integration Tests)

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-failsafe-plugin</artifactId>
    <version>3.2.3</version>
    <configuration>
        <includes>
            <include>**/*IT.java</include>
            <include>**/*IntegrationTest.java</include>
        </includes>
        <skipAfterFailureCount>3</skipAfterFailureCount>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>integration-test</goal>
                <goal>verify</goal>
            </goals>
        </execution>
    </executions>
</plugin>
```

### JaCoCo Plugin (Code Coverage)

```xml
<plugin>
    <groupId>org.jacoco</groupId>
    <artifactId>jacoco-maven-plugin</artifactId>
    <version>0.8.11</version>
    <executions>
        <execution>
            <id>prepare-agent</id>
            <goals>
                <goal>prepare-agent</goal>
            </goals>
        </execution>
        <execution>
            <id>report</id>
            <phase>test</phase>
            <goals>
                <goal>report</goal>
            </goals>
        </execution>
        <execution>
            <id>check</id>
            <goals>
                <goal>check</goal>
            </goals>
            <configuration>
                <rules>
                    <rule>
                        <element>BUNDLE</element>
                        <limits>
                            <limit>
                                <counter>LINE</counter>
                                <value>COVEREDRATIO</value>
                                <minimum>0.80</minimum>
                            </limit>
                            <limit>
                                <counter>BRANCH</counter>
                                <value>COVEREDRATIO</value>
                                <minimum>0.70</minimum>
                            </limit>
                        </limits>
                    </rule>
                </rules>
            </configuration>
        </execution>
    </executions>
</plugin>
```

## Quality Plugins

### Enforcer Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-enforcer-plugin</artifactId>
    <version>3.4.1</version>
    <executions>
        <execution>
            <id>enforce</id>
            <goals>
                <goal>enforce</goal>
            </goals>
            <configuration>
                <rules>
                    <requireMavenVersion>
                        <version>[3.8.0,)</version>
                    </requireMavenVersion>
                    <requireJavaVersion>
                        <version>[17,)</version>
                    </requireJavaVersion>
                    <dependencyConvergence/>
                    <requireUpperBoundDeps/>
                    <banDuplicatePomDependencyVersions/>
                    <bannedDependencies>
                        <excludes>
                            <exclude>commons-logging:commons-logging</exclude>
                            <exclude>log4j:log4j</exclude>
                        </excludes>
                    </bannedDependencies>
                </rules>
            </configuration>
        </execution>
    </executions>
</plugin>
```

### Checkstyle Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-checkstyle-plugin</artifactId>
    <version>3.3.1</version>
    <configuration>
        <configLocation>checkstyle.xml</configLocation>
        <consoleOutput>true</consoleOutput>
        <failsOnError>true</failsOnError>
        <violationSeverity>warning</violationSeverity>
        <includeTestSourceDirectory>true</includeTestSourceDirectory>
    </configuration>
    <executions>
        <execution>
            <id>checkstyle</id>
            <phase>validate</phase>
            <goals>
                <goal>check</goal>
            </goals>
        </execution>
    </executions>
    <dependencies>
        <dependency>
            <groupId>com.puppycrawl.tools</groupId>
            <artifactId>checkstyle</artifactId>
            <version>10.12.6</version>
        </dependency>
    </dependencies>
</plugin>
```

### SpotBugs Plugin

```xml
<plugin>
    <groupId>com.github.spotbugs</groupId>
    <artifactId>spotbugs-maven-plugin</artifactId>
    <version>4.8.3.0</version>
    <configuration>
        <effort>Max</effort>
        <threshold>Low</threshold>
        <xmlOutput>true</xmlOutput>
        <excludeFilterFile>spotbugs-exclude.xml</excludeFilterFile>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>check</goal>
            </goals>
        </execution>
    </executions>
</plugin>
```

### PMD Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-pmd-plugin</artifactId>
    <version>3.21.2</version>
    <configuration>
        <rulesets>
            <ruleset>/category/java/bestpractices.xml</ruleset>
            <ruleset>/category/java/errorprone.xml</ruleset>
        </rulesets>
        <failOnViolation>true</failOnViolation>
        <printFailingErrors>true</printFailingErrors>
        <includeTests>true</includeTests>
        <targetJdk>17</targetJdk>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>check</goal>
                <goal>cpd-check</goal>
            </goals>
        </execution>
    </executions>
</plugin>
```

## Packaging Plugins

### Assembly Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-assembly-plugin</artifactId>
    <version>3.6.0</version>
    <configuration>
        <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef>
        </descriptorRefs>
        <archive>
            <manifest>
                <mainClass>com.example.Main</mainClass>
            </manifest>
        </archive>
    </configuration>
    <executions>
        <execution>
            <id>make-assembly</id>
            <phase>package</phase>
            <goals>
                <goal>single</goal>
            </goals>
        </execution>
    </executions>
</plugin>
```

### Shade Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>3.5.1</version>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>shade</goal>
            </goals>
            <configuration>
                <transformers>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                        <mainClass>com.example.Main</mainClass>
                    </transformer>
                    <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer"/>
                </transformers>
                <filters>
                    <filter>
                        <artifact>*:*</artifact>
                        <excludes>
                            <exclude>META-INF/*.SF</exclude>
                            <exclude>META-INF/*.DSA</exclude>
                            <exclude>META-INF/*.RSA</exclude>
                        </excludes>
                    </filter>
                </filters>
                <relocations>
                    <relocation>
                        <pattern>com.google</pattern>
                        <shadedPattern>shaded.com.google</shadedPattern>
                    </relocation>
                </relocations>
            </configuration>
        </execution>
    </executions>
</plugin>
```

### WAR Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <version>3.4.0</version>
    <configuration>
        <failOnMissingWebXml>false</failOnMissingWebXml>
        <packagingExcludes>WEB-INF/classes/logback-test.xml</packagingExcludes>
        <webResources>
            <resource>
                <directory>src/main/webapp</directory>
                <filtering>true</filtering>
                <includes>
                    <include>**/*.html</include>
                </includes>
            </resource>
        </webResources>
    </configuration>
</plugin>
```

## Spring Boot Plugin

```xml
<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <version>3.2.0</version>
    <configuration>
        <mainClass>com.example.Application</mainClass>
        <excludes>
            <exclude>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
            </exclude>
        </excludes>
        <layers>
            <enabled>true</enabled>
        </layers>
        <image>
            <name>${project.artifactId}:${project.version}</name>
            <builder>paketobuildpacks/builder:base</builder>
        </image>
    </configuration>
    <executions>
        <execution>
            <goals>
                <goal>repackage</goal>
            </goals>
        </execution>
    </executions>
</plugin>
```

## Version Management Plugins

### Versions Plugin

```xml
<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>versions-maven-plugin</artifactId>
    <version>2.16.2</version>
    <configuration>
        <rulesUri>file:///${project.basedir}/version-rules.xml</rulesUri>
    </configuration>
</plugin>
```

```bash
# Check for updates
mvn versions:display-dependency-updates
mvn versions:display-plugin-updates
mvn versions:display-property-updates

# Update versions
mvn versions:update-properties
mvn versions:use-latest-releases
mvn versions:update-parent
```

### Release Plugin

```xml
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-release-plugin</artifactId>
    <version>3.0.1</version>
    <configuration>
        <tagNameFormat>v@{project.version}</tagNameFormat>
        <autoVersionSubmodules>true</autoVersionSubmodules>
        <releaseProfiles>release</releaseProfiles>
    </configuration>
</plugin>
```

## Code Generation Plugins

### Build Helper Plugin

```xml
<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>build-helper-maven-plugin</artifactId>
    <version>3.5.0</version>
    <executions>
        <execution>
            <id>add-source</id>
            <phase>generate-sources</phase>
            <goals>
                <goal>add-source</goal>
            </goals>
            <configuration>
                <sources>
                    <source>${project.build.directory}/generated-sources</source>
                </sources>
            </configuration>
        </execution>
    </executions>
</plugin>
```

### Exec Plugin

```xml
<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>exec-maven-plugin</artifactId>
    <version>3.1.1</version>
    <executions>
        <execution>
            <id>run-script</id>
            <phase>generate-sources</phase>
            <goals>
                <goal>exec</goal>
            </goals>
            <configuration>
                <executable>bash</executable>
                <arguments>
                    <argument>${project.basedir}/scripts/generate.sh</argument>
                </arguments>
            </configuration>
        </execution>
    </executions>
</plugin>
```

## Best Practices

1. **Version Pinning** - Always specify plugin versions
2. **Plugin Management** - Centralize in parent POM
3. **Minimal Configuration** - Use defaults where possible
4. **Execution IDs** - Use meaningful execution IDs
5. **Phase Binding** - Bind to appropriate phases
6. **Skip Properties** - Provide skip properties for flexibility
7. **Documentation** - Comment complex configurations
8. **Inheritance** - Use pluginManagement for multi-module
9. **Updates** - Keep plugins current
10. **Profile Separation** - Separate CI/release plugins into profiles

## Common Pitfalls

1. **Missing Versions** - Relying on default versions
2. **Wrong Phase** - Plugin bound to wrong lifecycle phase
3. **Duplicate Executions** - Same goal running multiple times
4. **Memory Issues** - Insufficient heap for plugins
5. **Ordering** - Plugin execution order conflicts
6. **Inheritance** - Unintended plugin inheritance
7. **Fork Confusion** - Misunderstanding fork behavior
8. **Skip Flags** - Tests accidentally skipped in CI

## When to Use This Skill

- Configuring build compilation settings
- Setting up test frameworks
- Configuring code quality checks
- Creating executable JARs
- Setting up CI/CD builds
- Optimizing build performance
- Generating source code
- Managing releases and versions