Maven - Maven Plugin - maven tutorial
maven tutorial tags : apache maven , maven repository , maven central
What is 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:
learn maven tutorial - apache maven maven plugin based architecture - Apache Maven example programs
Learn Maven Tutorial - Maven Plugin - Maven Example
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 [plugin-name]:[goal-name]
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. |
Example:
- We've used maven-antrun-plugin extensively in our examples to print data on console.
- Then create a pom.xml in C:\MVN\project folder.
maven tutorial tags : apache maven , maven repository , maven central
Sample Code
<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 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 show clean phase of clean life cycle
maven tutorial tags : apache maven , maven repository , maven central
Output
[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 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.