Correlation between parent and child POMs in MuleSoft

Introduction

In MuleSoft, the POM file is typically used to define the dependencies and configurations needed for Mule applications and APIs. This includes things like Mule runtime version, third-party libraries, custom modules, and various other settings that affect how the project is built and run. In this article we are going to establish a connection between parent and child pom.xml on real time example.

Advantages

Reusability: By defining common configurations, properties, and dependencies in a parent POM, developers can reuse these settings across multiple child projects, reducing duplication and simplifying maintenance.

Consistency: Using a parent POM ensures that all child projects have the same basic configuration, which can help to maintain consistency across a larger codebase.

Scalability: When a project grows in complexity, it may become necessary to split it into multiple smaller projects. By using a parent POM, developers can easily manage these child projects, as they inherit the configuration and dependencies from the parent POM.

Flexibility: Child POMs can override or add new configurations or dependencies, while still inheriting the default configurations from the parent POM. This provides developers with flexibility in how they manage their projects.

Maintenance: Parent POMs can be updated to include new or updated dependencies or configurations, which can then be propagated to all child projects that inherit from them, simplifying the process of maintaining and upgrading project dependencies.

Let’s start with an example!

Before we start with single steps let’s create a simple parent pom.xml file with defined version of connectors we are using in the child project.

<!-- Parent POM -->
<project>
  <modelVersion>4.0.0</modelVersion>
  <name>Test Parent POM</name>
  <description>A parent pom project to be used in documentation</description>
  <groupId>com.mycompany</groupId>
  <artifactId>parent-pom</artifactId>
  <version>1.0.0-GC-TEST</version>
  <packaging>pom</packaging>
  
  <properties>
        <activemq-client-version>5.15.4</activemq-client-version>
        <mule-http-connector-version>2.1.1</mule-http-connector-version>
  </properties>

</project>

First Step

In order to successfully inherit the values defined in parent pom.xml, first step is to run a maven command in the directory where parent pom.xml is located.

mvn clean install

Second Step

Second step is to copy create a reference between parent pom.xml and the child pom.xml file.

<parent>
        <groupId>com.mycompany</groupId>
        <artifactId>parent-pom</artifactId>
        <version>1.0.0-GC-TEST</version>
        <relativePath/>
</parent>

Third Step

Copy the code and put the dependencies in an appropriate place in your pom.xml file.

 <dependencies>
  <dependency>
   <groupId>org.apache.activemq</groupId>
   <artifactId>activemq-client</artifactId>
   <version>${activemq-client-version}</version>
  </dependency>
  <dependency>
   <groupId>org.mule.connectors</groupId>
   <artifactId>mule-http-connector</artifactId>
   <version>${mule-http-connector-version}</version>
   <classifier>mule-plugin</classifier>
  </dependency>
 </dependencies>

Conclusion

Overall, using parent and child POMs can simplify the process of managing complex MuleSoft projects, reduce duplication and inconsistency and provide greater flexibility and scalability.