Maven - In Real Time

A perfect dependency management tool that most of us have used in our projects.

I would like to share some real-time problem scenarios that Maven is able to address pretty well.

Mr.Yan is working as a build management engineer. He takes care of the build and deploy environment in his company on a daily basis.

After doing is routine tasks, he was frustated due to the increasing work load because of multiple OS and Java versions. His entire day was gone in editing the property files and pom files.

Finally, he started searching for a tool that would help make his work easier and atlast founfd it to be Maven... After going through the documentation, he realized "Profiles" in maven can do it.

What a Maven Profile can do for us?

Maven Profile is used for the following:

   * Package the Build in different formats
   * Dynamically inject the dependencies
   * choose which source files or resources to be inculded/excluded for build (optional java files includes & excludes)
   * Activation based on various JDK version/OS version/Property(only System Property)

Lets see a quick snapshot of Pom,

<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>MyTest</groupId>
    <artifactId>MyTest</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <profiles>
        <profile>
            <id>yan1</id>
            <activation>
             <activeByDefault>false</activeByDefault>
                <jdk>1.5</jdk> <!--this profile will be activated if the JDK is 1.5 -->
            </activation>
            <build>
                <plugins>
                    <plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-compiler-plugin</artifactId>
                        <configuration>
                            <source>1.5</source>
                            <target>1.5</target>
                            <includes> <!--can include/Exclude the sources based on the profile -->
                                <include>**/MyTest1.java</include>
                                <include>**/service/**</include>
                            </includes>
                        </configuration>
                    </plugin>
                </plugins>
            </build>
            <dependencies><!-- we can tell the dependencies for this profile alone--></dependencies>
        </profile>
        <profile>
            <id>yan2</id>
            <activation>
             <activeByDefault>false</activeByDefault>
                <property><!--this profile will be activated when the system property hq.version is 2 -->
                    <name>hq.version</name>
                    <value>2</value>
                </property>
            </activation>
            <build>
                <plugins>
                    <plugin>
                        <groupId>org.apache.maven.plugins</groupId>
                        <artifactId>maven-compiler-plugin</artifactId>
                        <configuration>
                            <source>1.5</source>
                            <target>1.5</target>
                            <excludes><!--can include/Exclude the sources based on the profile -->
                                <exclude>**/MyTest2.java</exclude>
                            </excludes>
                        </configuration>
                    </plugin>
                </plugins>
            </build>
            <dependencies><!-- we can tell the dependencies for this profile alone--></dependencies>
        </profile>
    </profiles>
</project>

This made his life easier... Now Yan wants to activate a profile and he types a simple command

mvn -P profileName

and he wants to call using properties

mvn -Dprop=value

After doing all these changes, now he is enjoying his life without any manual work in build managment :) :)