referencing modules in pom packaging - maven-3

Question

How do I reference a module that is included in a pom.xml?
In the pom.xml referenced below how would I include the modules on the this pom so that it can be referenced in other projects as so:
<dependency>
<groupId>com.example</groupId>
<artifactId>parent</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>parent</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<modules>
<module>module1</module>
<module>module2</module>
<module>module3</module>
</modules>
<dependencies>
<dependency>
<groupId>org.codehaus.jettison</groupId>
<artifactId>jettison</artifactId>
<version>1.3.3</version>
</dependency>
</dependencies>
</project>

Answer 1

I think the best you can do is to put your sub-modules in the dependencyManagement section of your parent POM like so:
<dependencyManagement>
<dependencies>
<dependency>
<groupId>com.example</groupId>
<artifactId>module1</artifactId>
<version>${project.version}</version>
</dependency>
<dependency>
<groupId>com.example</groupId>
<artifactId>module2</artifactId>
<version>${project.version}</version>
</dependency>
<dependency>
<groupId>com.example</groupId>
<artifactId>module3</artifactId>
<version>${project.version}</version>
</dependency>
<dependencies>
</dependencyManagement>
Then you can configure each of your sub-modules with whatever dependencies they need, without having to worry about the correct version number.
<!-- module2's dependencies -->
<dependencies>
<dependency>
<groupId>com.example</groupId>
<artifactId>module1</artifactId>
</dependency>
<dependency>
<groupId>com.example</groupId>
<artifactId>module3</artifactId>
</dependency>
<dependencies>
If you declared all the sub-modules as dependencies of the parent POM, then you'd end up with cyclic dependencies. For example:
[parent] -> [module1] -> [parent]
Maven doesn't like that.