This mini guide explains howto use Maven in Eclipse IDE.
Eclipse needs to know the path to the local maven repository. Therefore the classpath variable M2_REPO has to be set.
You can also a new classpath variable inside Eclipse: From the menu bar, select Window > Preferences. Select the Java > Build Path > Classpath Variables page.
You might want to execute some maven goals from inside Eclipse. This is possible by configuring an external launcher.
It is best practice to prepare Eclipse by adding a variable, which points to your local maven excutable (mvn.bat/mvn).
From the menu bar, select Window > Preferences. Select the Run/Debug > String Substitution. Add a new variable e.g. maven_exec.
When you set up a new external launcher (from the menu bar, select Run > External Tools. Select Program) you can refer to maven_exec in the location field.
Furthermore refer to project_loc as the working directory and specify the maven goals of your choice as arguments, e.g. eclipse:eclipse.
For further information please refer to the Eclipse help.
If you have a simple java project which is made up of only one module, using Eclipse is very simple. To generate the Eclipse project files from your POM you execute the following command:
mvn eclipse:eclipse
If you have created or checked out the project with Eclipse, you only have to refresh the project in your workspace. Otherwise you have to import the project into your Eclipse workspace (From the menu bar, select File > Import > Existing Projects into Workspace). In the latter case the project (directory) should not be located in your workspace, because Eclipse might come into trouble, especially if you want to use Eclipse as the scm client.
If your maven project has dependencies, the eclipse classpath will be synchronised with the current list of maven dependencies, as well as any transitive maven dependencies.
After making changes to your maven dependencies inside the pom file, rerun eclipse:eclipse and refresh your eclipse workspace for the new dependencies to take effect.
If your maven project consists of a number of aggregated projects with a common root pom, and if some of these aggregated projects depend on each other, the eclipse:eclipse goal will configure each dependent project in eclipse as an eclipse project dependency, rather than an eclipse jar dependency.
By doing this, changes to code within project A will be available immediately to project B, assuming that project B defines a dependency on project A.
For further details, see Multiple Module Projects.