Maven：在pom.xml中编译外部依赖项

Question

We have a Common git repository containing a parent pom.xml and some modules. The parent pom.xml looks like this (simplified):

<modelVersion>4.0.0</modelVersion>
<groupId>group</groupId>
<artifactId>common</artifactId>
<packaging>pom</packaging>

<modules>
    <!-- Utility classes -->
    <module>utils</module>
    <!-- Data transfer objects -->
    <module>dto</module>
</modules>

</dependencyManagement>
    <dependencies>
        <dependency>
            <!-- Version of the module -->
            <groupId>group</groupId>
            <artifactId>utils</artifactId>
            <version>1.0</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish</groupId>
            <artifactId>javax.el</artifactId>
            <version>3.0.0</version>
        </dependency>
        ...
    </dependencies>
</dependencyManagement>

The dependencyManagement is used to provide consistent versioning across all modules.

Now we want to use parts of the Common modules in other projects (own git repository each) and still keep the dependencyManagement . Thus, we created, for instance, a ProjectX repository and added Common as an git-submodule . ProjectX has the following pom.xml (simplified):

<parent>
    <groupId>group</groupId>
    <artifactId>common</artifactId>
    <relativePath>../Common/pom.xml</relativePath>
</parent>

</dependencies>
    <dependency>
        <groupId>group</groupId>
        <artifactId>utils</artifactId>
    </dependency>
    <dependency>
        <groupId>org.glassfish</groupId>
        <artifactId>javax.el</artifactId>
    </dependency>
</dependencies>

This way, we can use classes of Common.utils and have dependency consistency. However, after each update of Common we have to call:

mvn clean install

in the Common git-submodule for ProjectX pom.xml to find the utils dependency.

Question:

• Can the maven command be integrated into the pom.xml?
• Is there a better way to handle the submodule dependency?

Answer 1

The construction with the git submodule is unfortunate. I would not do it, this is not Maven philosophy.

I would separate two things:

• If you need one of the modules outside the multi-module project, just declare it as dependency in the usual way.

• If you want to share configuration or dependencyManagement between the multi-module project and other projects, construct a parent pom that you use for the different projects (may they be multi-module or not).