Maven - Plug-ins


What are Maven Plugins?

Maven is actually a plugin execution framework where every task is actually done by plugins. Maven Plugins are generally used to :

  • create jar file

  • create war file

  • compile code files

  • unit testing of code

  • create project documentation

  • create project reports

A plugin generally provides a set of goals and which can be executed using following syntax:

mvn [plugin-name]:[goal-name]

For example, a Java project can be compiled with the maven-compiler-plugin's compile-goal by running following command

mvn compiler:compile

Plugin Types

Maven provided following two types of Plugins:

Type Description
Build plugins They execute during the build and should be configured in the <build/> element of pom.xml
Reporting plugins They execute during the site generation and they should be configured in the <reporting/> element of the pom.xml

Following is the list of few common plugins:

Plugin Description
clean Clean up target after the build. Deletes the target directory.
compiler Compiles Java source files.
surefire Run the JUnit unit tests. Creates test reports.
jar Builds a JAR file from the current project.
war Builds a WAR file from the current project.
javadoc Generates Javadoc for the project.
antrun Runs a set of ant tasks from any phase mentioned of the build.


We've used maven-antrun-plugin extensively in our examples to print data on console. See Maven Build Profiles chapter. Let to understand it in a better way let's create a pom.xml in C:\MVN\project folder.

<project xmlns=""
               <echo>clean phase</echo>

Next, open command console and go to the folder containing pom.xml and execute the following mvn command.

C:\MVN\project>mvn clean

Maven will start processing and display clean phase of clean life cycle

[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------
[INFO] Building Unnamed - com.companyname.projectgroup:project:jar:1.0
[INFO]    task-segment: [post-clean]
[INFO] ------------------------------------------------------------------
[INFO] [clean:clean {execution: default-clean}]
[INFO] [antrun:run {execution: id.clean}]
[INFO] Executing tasks
     [echo] clean phase
[INFO] Executed tasks
[INFO] ------------------------------------------------------------------
[INFO] ------------------------------------------------------------------
[INFO] Total time: < 1 second
[INFO] Finished at: Sat Jul 07 13:38:59 IST 2012
[INFO] Final Memory: 4M/44M
[INFO] ------------------------------------------------------------------

The above example illustrates the following key concepts:

  • Plugins are specified in pom.xml using plugins element.

  • Each plugin can have multiple goals.

  • You can define phase from where plugin should starts its processing using its phase element. We've used clean phase.

  • You can configure tasks to be executed by binding them to goals of plugin. We've bound echo task with run goal of maven-antrun-plugin.

  • That's it, Maven will handle the rest. It will download the plugin if not available in local repository and starts its processing.