To customize the behavior of a Maven Plugin, you will need to configure the plugin in a project’s POM. The following sections outline the various methods available for customizing a Maven plugin’s configuration.
Maven plugins are configured using properties that are defined by goals within a plugin. If you look at a goal like the compile goal in the Maven Compiler Plugin you will see a list of configuration parameters like source, target, compilerArgument, fork, optimize, and many others.
If you look at the testCompile goal you will see a different list of configuration parameters.
If you are looking for details on the available plugin configuration parameters, you can use the Maven Help Plugin to describe a particular plugin or a particular plugin goal.
To describe a particular plugin, use the help:describe goal from the command line. For more information about the available configuration parameters, run the same command with the -Ddetail argument:
$ mvn help:describe -Dcmd=compiler:compile -Ddetail
[INFO] [help:describe {execution: default-cli}]
[INFO] 'compiler:compile' is a plugin goal (aka mojo).
Mojo: 'compiler:compile'
compiler:compile
Description: Compiles application sources
....If you need to get a list of plugin goals which are contained in a plugin, you can run the help:describe goal and pass in the plugin parameter.
The plugin parameter accepts a plugin prefix or a groupId and an artifactId for a plugin as shown in the following examples:
$ mvn help:describe -Dplugin=compilerYou can use the groupId and the artifactId of the plugin and get the same list of plugin goals.
$ mvn help:describe -Dplugin=org.apache.maven.plugins:maven-compiler-pluginPassing the -Ddetail argument to the help:describe goal with the plugin parameter will cause Maven to print out all of the goals and all of the goal parameters for the entire plugin.
If you need to configure a plugin to use specific versions of dependencies, you can define these under a dependencies element, under the plugin element. Thus, when the plugin executes, it will do so with a classpath that contains these dependencies. Adding Dependencies to a Plugin is an example of a plugin configuration that overrides default dependency versions and adds new dependencies to facilitate goal execution.
<plugin>
<groupId>com.agilejava.docbkx</groupId>
<artifactId>docbkx-maven-plugin</artifactId>
<version>2.0.9</version>
<dependencies>
<dependency>
<groupId>docbook</groupId>
<artifactId>docbook-xml</artifactId>
<version>4.5</version>
</dependency>
<dependency>
<groupId>org.apache.fop</groupId>
<artifactId>fop-pdf-images</artifactId>
<version>1.3</version>
</dependency>
<dependency>
<groupId>org.apache.fop</groupId>
<artifactId>fop-pdf-images-res</artifactId>
<version>1.3</version>
<classifier>res</classifier>
</dependency>
<dependency>
<groupId>pdfbox</groupId>
<artifactId>pdfbox</artifactId>
<version>0.7.4-dev</version>
<classifier>dev</classifier>
</dependency>
</dependencies>
</plugin>To set a value for a plugin configuration parameter in a particular project, use XML like that shown in
Configuring a Maven Plugin.
Unless this configuration is overridden by a more specific plugin parameter configuration, Maven will use the values defined directly under the plugin element for all goals which are executed in this plugin.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>13</source>
<target>13</target>
</configuration>
</plugin>You can configure plugin parameters for specific executions of a plugin goal. Setting Configuration Parameters in an Execution shows an example of configuration parameters being passed to the execution of the run goal of the AntRun plugin during the validate phase.
This specific execution will inherit the configuration parameters from the plugin’s configuration element, and merge them with the values defined for this particular execution.
<plugin>
<artifactId>maven-antrun-plugin</artifactId>
<executions>
<execution>
<phase>validate</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<tasks>
<echo>${PATH}=${env.PATH}</echo>
<echo>User's Home Directory: ${user.home}</echo>
<echo>Project's Base Director: ${basedir}</echo>
</tasks>
</configuration>
</execution>
</executions>
</plugin>You can also supply configuration parameters for goals which are executed from the command-line.
To do this, use the special execution id value of "default-cli". The example below (Configuring Plugin Parameters for Command Line Execution) binds the single goal to the package phase of the lifecycle which produces a binary distribution.
It also configures the default-cli execution for the assembly plugin to use the jar-with-dependencies assembly descriptor.
In this case, the bin.xml descriptor will be used during the lifecycle, and jar-with-dependencies will be used when you execute mvn assembly:assembly from the command line.
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<appendAssemblyId>false</appendAssemblyId>
</configuration>
<executions>
<execution>
<id>assemble-binary</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
<configuration>
<descriptors>
<descriptor>src/main/assembly/bin.xml</descriptor>
</descriptors>
</configuration>
</execution>
<execution>
<id>default-cli</id>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</execution>
</executions>
</plugin>If you need to customize the behavior of a goal which is already bound to the default lifecycle, you can use the execution id "default-<goal>".
You can also customize the behavior of the Jar plugin’s jar goal, which is bound to the package phase in the default lifecycle, and customize the configuration parameters of a separate goal execution if you follow the example below.
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<executions>
<execution>
<id>default-jar</id>
<configuration>
<excludes>
<exclude>**/somepackage/*</exclude>
</excludes>
</configuration>
</execution>
<execution>
<id>special-jar</id>
<phase>package</phase>
<goals>
<goal>jar</goal>
</goals>
<configuration>
<includes>
<include>**/sompackage/*</include>
</includes>
<classifier>somepackage</classifier>
</configuration>
</execution>
</executions>
</plugin>In this example, the default jar goal is customized to exclude contents in a specific package.
Another jar goal is bound to the package phase to create a JAR file containing only the contents of a particular package in a classified JAR file.
Configuring the default goal execution parameters can also come in handy if you need to configure two goals bound to the default lifecycle with separate settings for the same configuration parameter. The example Setting Two Default Goal Plugin Configuration Parameters configures the default resources:resources goal to exclude empty directories, while configuring the default resources:testResources goal to include empty directories.
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<executions>
<execution>
<id>default-resources</id>
<configuration>
<includeEmptyDirs>false</includeEmptyDirs>
</configuration>
</execution>
<execution>
<id>default-testResources</id>
<configuration>
<includeEmptyDirs>true</includeEmptyDirs>
</configuration>
</execution>
</executions>
</plugin>