Dependency Management, WTF?

The problem:

You want to standardize versions of a set of dependencies used in a group of project.

The solution:

A set of projects may use a given dependency. I know that I often use both Hibernate 3.x and Spring 2.x in my projects. It can make a lot of sense to use the same versions of dependencies across multiple projects. This may be especially important when you have a set of projects that are very closely related, maybe with dependencies to one another. Enter the dependency management function of the Maven pom. I put WTF in the title because thats what I thought when I discovered this feature for myself. It really is a well thought addition to the Maven platform.

So how do you do this? First you will want to put a dependency management section in a pom. Likely this is a parent pom which is inherited by many projects, otherwise what is the point? I MEAN DEPENDENCY MANAGEMENT IS MEANT FOR MANAGING DEPENDENCIES ACROSS MANY POMS. Sorry that was the main point you should take away from this session.

Here is what the dependency management section will look like:

<dependencyManagement>
   <dependencies>
       <dependency>
           <groupdId>org.springframework</groupId>
           <artifactId>spring</artifactId>
           <version>2.1</version>
       </dependency>
   <dependencies>
</dependencyManagement>

So that will set the version of the shown spring artifact to 2.1. Now how will this make a difference? You will not include a version when adding this dependency in a project which has this dependency management section. You will simply add this dependency config:

<dependency>
    <groupdId>org.springframework</groupId>
    <artifactId>spring</artifactId>
</dependency>

It is pretty simple, Eh? Also note that when you want to upgrade to a new version of a dependency it is as simple as changing the version in the parent pom's dependency management section. Hows that for simple management of your dependencies?