Maven within 5 minutes

HOW TO CREATE A MAVEN PROJECT


======First create a directory  and start a shell in that  created directory.On your command line,and  execute the following command:

mvn archetype:generate -DgroupId=com.mycompany.app -DartifactId=my-app -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false

    groupId : package name of the project
    artifactId : Project name
    archetypeArtifactId : name of the archetype to be used


Under the my-app directory ,you can notice the following standard project structure.

my-app
|-- pom.xml
`-- src
    |-- main
    |   `-- java
    |       `-- com
    |           `-- mycompany
    |               `-- app
    |                   `-- App.java
    `-- test
        `-- java
            `-- com
                `-- mycompany
                    `-- app
                        `-- AppTest.java




Project source code is in src/main/java directory ,
Test source is in src/test/java directory ,
The pom.xml file is the project's Project Object Model(POM).


The POM

The core of a project's configuration in Maven is the pom.xml file.
It is a single configuration file that contains the majority of information required to build a project.


This project's POM is:

<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.mycompany.app</groupId>
  <artifactId>my-app</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>Maven Quick Start Archetype</name>
  <url>http://maven.apache.org</url>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.8.2</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>






=========To Build the Project

mvn package

The command line will print out various actions, and end with the following:

 ...
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESSFUL
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2 seconds
[INFO] Finished at: Thu Jul 07 21:34:52 CEST 2011
[INFO] Final Memory: 3M/6M
[INFO] ------------------------------------------------------------------------

we can execute the compile phase, the phases that actually get executed are:

validate
generate-sources
process-sources
generate-resources
process-resources
compile

We can  test the compiled and packaged JAR with the following command:

java -cp target/my-app-1.0-SNAPSHOT.jar com.mycompany.app.App

Which will print the quintessential:

Hello World!