Apache Maven plug-in

Maven - plug-in

What is a Maven plug-in?

Maven is actually a framework that relies on plug-in execution, and each task is actually done by the plug-in. Maven plug-ins are often used to:

• Create a jar file
• Create a war file
• Compile the code file
• Code unit tests
• Create a project document
• Create an engineering report

Plug-ins typically provide a collection of targets and can be executed using the following syntax:

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

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

mvn compiler:compile

The type of plug-in

Maven provides two types of plug-ins:

Here's a list of some common plug-ins:

Example

We've used maven-antrun-plugin a lot in our example to output data to the console. C heck out the Maven - Build Profiles section. Let's understand this in a better way, creating a pom-and-file in the C:?MVN.xml directory.

<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
    http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.companyname.projectgroup</groupId>
<artifactId>project</artifactId>
<version>1.0</version>
<build>
<plugins>
   <plugin>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-antrun-plugin</artifactId>
   <version>1.1</version>
   <executions>
      <execution>
         <id>id.clean</id>
         <phase>clean</phase>
         <goals>
            <goal>run</goal>
         </goals>
         <configuration>
            <tasks>
               <echo>clean phase</echo>
            </tasks>
         </configuration>
      </execution>     
   </executions>
   </plugin>
</plugins>
</build>
</project>

Next, open the command terminal to jump to the directory .xml where the pom terminal is located, and execute the following mvn command.

C:\MVN\project>mvn clean

Maven will begin processing and displaying the clean phase of the clean lifecycle.

[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] BUILD SUCCESSFUL
[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 shows the following key concepts:

• Plug-ins are .xml the plugins element in the pom element.
• Each plug-in can have multiple targets.
• You can define a stage, and the plug-in uses its phase element to start processing. We've already used the clean phase.
• You can configure the tasks to perform by binding to the target of the plug-in. We have bound the echo task to the run target of maven-antrun-plugin.
• That's it, Maven will take care of the rest. It will download plug-ins that are not available in the local repository and start processing.