Playing around with maven

Today I played around with maven while working on a personal project and it turned out to be a great decision.

What I learned

What I learned in the process:

Using maven plugins

Maven plugins can reduce a lot of work when it comes to automating things. I used maven-assembly-plugin to create an executable jar file, which includes all the resources and dependencies of the project as well. In my project, I added this part to my plugins:


<plugin>    <artifactId>maven-assembly-plugin</artifactId>    <configuration>        <archive>            <manifest>                <mainClass>path.to.MainClass</mainClass>                <addClasspath>true</addClasspath>            </manifest>        </archive>        <descriptorRefs>            <descriptorRef>jar-with-dependencies</descriptorRef>        </descriptorRefs>    </configuration>    <executions>        <execution>            <id>make-assembly</id> <!-- this is used for inheritance merges -->            <phase>package</phase> <!-- bind to the packaging phase -->            <goals>                <goal>single</goal>            </goals>        </execution>    </executions></plugin>

This will generate an executable jar file in the target folder for you. But, it can be tricky if you are using a local jar file as a dependency.

Using local maven repository

I also learned how to use an existing jar file as a local maven repository. - Run this command:


mvn org.apache.maven.plugins:maven-install-plugin:2.3.1:install-file -Dfile=<jarfilepath> -DgroupId=<groupId> -DartifactId=<artifactId> -Dversion=<version> -Dpackaging=jar -DlocalRepositoryPath=<localRepositoryPath>

This will create a local repository in the specified location, which you can then add to the pom file directly. This method is preferred way more than using the system scope in maven.

Extending a Windows application to Unix-based systems

I was planning to port my Java application built using SWT to other operating systems for a long time. After starting to use Maven as the package manager for my application (I am working on an old project when I wasn’t aware of Maven), I realized how easy that made a developer’s life. Earlier I was importing SWT normally, like this:


<dependency>    <groupId>org.eclipse.swt</groupId>    <artifactId>org.eclipse.swt.win32.win32.x86_64</artifactId>    <version>4.3</version></dependency>

Now, for building and running the same app on Linux, I just had to add a new profile to maven, and it would do everything by itself! The updated pom file looks like this:


<profiles>        <profile>            <id>Windows-config</id>            <activation>                <os>                    <family>Windows</family>                </os>            </activation>            <dependencies>                <dependency>                    <groupId>org.eclipse.swt</groupId>                    <artifactId>org.eclipse.swt.win32.win32.x86_64</artifactId>                    <version>4.3</version>                </dependency>            </dependencies>        </profile>        <profile>            <id>Linux-config</id>            <activation>                <os>                    <family>unix</family>                </os>            </activation>            <dependencies>                <dependency>                    <groupId>org.eclipse.swt</groupId>                    <artifactId>org.eclipse.swt.gtk.linux.x86_64</artifactId>                    <version>RELEASE</version>                </dependency>            </dependencies>        </profile></profiles>

Looks cool, right? I now understand why maven is so widely accepted and used. I would say that porting to maven was one of the best things I did for my project.