Hello World - Maven, M2Eclipse and Eclipse

This tutorial takes you through all steps needed to create a Hello World Java Application using Maven, M2Eclipse and Eclipse from scratch. The instructions are geared toward a Windows machine, but you should probably be able to easily adapt the steps to apply to Linux or Mac OS X.

Eclipse

Step 1: Download Eclipse. Download the lastest version of Eclipse at the Main Eclipse download page. You can download which ever flavor of Eclipse you like the best. I chose Eclipse IDE for J2EE Developers.

Step 2: Install Eclipse. Unpack the Eclipse .zip file and move the entire folder 'eclipse' to the 'Programs' folder on the hard drive.

M2Eclipse

Step 3. In Eclipse, go to Help --> 'Eclipse Marketplace...' and search for 'Maven'. Click on 'Install' for the m2eclipse plugin title 'Maven Integration for Eclipse'.

Step 4: Click through the wizard, installing m2eclipse.

Maven (Optional)

Installing Maven is optional because M2Eclipse does have its own embedded version of Maven. I chose to install Maven separately for two reasons. First, I wanted the latest and greatest version of Maven. Secondly, I plan to run a CI server (Jenkins) that needs access to Maven, and I wanted M2Eclipse and Jenkins to both use the same Maven install. If you don't plan on installing Maven separetely, skip to step 10.

Step 5: Download Maven. Download the lastest version of Maven at the Main Apache Maven download page choosing the binary .zip file for Windows.

Step 6: Install Maven. Unpack the Maven .zip file and move the entire folder 'apache-maven.x.x.x' to the 'Programs' folder on the hard drive.

Step 7: Set environment variables (adjust according to your setup):

JAVA_HOME C:\Program Files\Java\jdk1.6.0_25
M2_HOME C:\Program Files\apache-maven-3.0.4
M2 %M2_HOME%\bin

Path ;%M2%;%JAVA_HOME%\bin

Step 8: Verify Maven install with 'mvn -- version' at the command line. Note, if you had the command line open before changing the environment variables, close it and reopen it.

>mvn --version
Apache Maven 3.0.4 (r1232337; 2012-01-17 09:44:56+0100)
Maven home: C:\Program Files\apache-maven-3.0.4
Java version: 1.6.0_25, vendor: Sun Microsystems Inc.
Java home: C:\Program Files\Java\jdk1.6.0_25\jre
Default locale: de_DE, platform encoding: Cp1252
OS name: "windows 7", version: "6.1", arch: "x86", family: "windows"

Step 9: Configure m2eclipse. In Eclipse, go to Window --> Preferences

9.a. Under Maven --> Installations, specify an external Maven install by clicking 'Add...' next to 'Select the installation used to launch Maven'. By default m2eclipse selects it's own embedded Maven version.

9.b. Under Maven --> User Settings, specify a settings.xml by clicking 'Browse...'. I chose to put the settings.xml file inside Mave's conf folder.

9.c. Edit the settings.xml file and specify the location of the local Maven repository. I chose 'C:\Program Files\apache-maven-3.0.4\repository'. After editing settings.xml click the 'Update Settings' in 'User Settings' from the previous step.

A repository in Maven is used to hold build artifacts and dependencies of varying types. The local repository refers to a copy on your own installation that is a cache of the remote downloads, and also contains the temporary build artifacts that you have not yet released.

Hello World

Step 10: Create Maven Project in Eclipse.

10.a. In Eclipse open the New Project Wizard by clicking File --> New --> Project. Under 'Maven' select 'Maven Project' and click 'Next'.

10.b. On the next page of the wizard, check 'Create a simple project' and click 'Next'.

10.c. Give a 'Group Id' and an 'Artifact Id' and click 'Finish'.

Step 11: Create a class with a main method in src/main/java. In this case I created MelloMavenMain.java.

Step 12: In the main method, log a message using slf4j. I chose to use a 3rd party library to do this to demonstrated how to depend on 3rd party libraries in the next step.

Logger logger = LoggerFactory.getLogger(HelloMavenMain.class);
logger.info("Hello Maven!");

Step 13: Add the slf4j dependency in the project's pom.xml file.

  
    org.slf4j
    slf4j-simple
    1.6.4
  

Step 14: Package your program. Right-click on the project and choose Run As... --> 'Maven Install'. This will create a jar file for your project in the 'target' directory.

Piece of Cake!!!

Helpful Links

Maven Documentation
m2eclipse
Maven Eclipse Plugin