Introduction to Maven GroupID

What is GroupID?

Like names are to Human Beings, GroupID is to projects developed using Maven. The Maven GroupID is the ID of the entire project group. GroupID is a unique entity among all the projects.

The GroupID follows the naming convention of the Java Package name, which starts with the reserved domain name. Maven needs to enforce the rule as multiple legacies have yet to follow the pattern and, instead of doing the same, end up using single-word GroupIDs.

It is rather challenging to obtain a single-word GroupID approved by the Maven Inclusion and Central Repository.

To make things even more modular, Maven GroupID allows us to create multiple sub-groups to make things easier. We can determine the granularity of the GroupID by using the Project structure.

Project Configuration in Maven is done using the Project Object Model, represented by the file pom.xml. The POM describes the dependencies managed by the Project and proves helpful in the plugin configuration for software building. 

The POM file also keeps a record of relationships between multi-module projects.

Maven GroupID Naming

When working with Maven GroupID, the thing to note about the class file is that we do not have to pick a name for them; it will automatically choose its name by utilizing the 1:1 mapping from the Java File.

Maven only asks us to pick two names; therefore, it is relatively simple. Thus to define the Maven GrouID name, the below steps have to be followed:

Step 1: Create a Template for the Project in the Spring Initializer. The figure below shows a template of the Maven GroupID naming project.

Enter the details as follows:

Group Name: com.Group_ID
Artifact: Maven_Group_ID
Name: Maven_Group_ID
Packaging: JAR
Java Version 8

Step 2: After creating the template, extract the template file and open the same in VS Code or any other Editor or IDE with Spring Boot Functionalities.

The pom.xml File in the Project should be as follows.

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.7.5</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.Group_ID</groupId>
	<artifactId>Maven_Group_ID</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>Maven_Group</name>
	<description>Demo project for Spring Boot</description>
	<properties>
		<java.version>1.8</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

In the example below, we define naming conventions as:

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.5</version>
        <relativePath/> <!-- lookup parent from repository -->
 </parent>
 
 <groupId>com.Group_ID</groupId>
 <artifactId>Maven_Group_ID</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <name>Maven_Group_ID</name>
 <description>Demo project for Spring Boot</description>

We can also modify the name/Group ID of the Project by changing the contents in the name tag as:

<name>Maven_Group_ID</name>

The pom.xml file looks like below:

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.7.5</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	
	<groupId>com.Group_ID</groupId>
	<artifactId>Maven_Group_ID</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>Maven_Group</name>
	<description>Demo project for Spring Boot</description>
	
	<properties>
		<java.version>1.8</java.version>
	</properties>
	
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
				<dependencies>
					<dependency>
						<groupId> maven_group </groupId>
						<artifactId> RestrictionRule </artifactId>
						<version> 0.0.1 </version>
					</dependency>
				</dependencies>
			</plugin>
		</plugins>
	</build>

</project>

Restricting the GroupID

Maven restricts the usage of GroupIDs for the Project to enforce the source code. Here is how we can implement a single group restriction on the GroupID in Maven:

<dependency>
	<groupId> Maven_Group_ID </groupId>
	<artifactId> RestrictionRule </artifactId>
	<version> 0.0.1 </version>
</dependency>

How is GroupID different from ArtifactID?

The below table briefly discusses the differences between the Maven GroupID and the ArtifactID.

Frequently Asked Questions

What is GroupID in Maven?

GroupID is n unique identifying feature of all the projects currently being worked on in Maven. It can be automated or the user can define the GroupID by themselves as well.

What is POM?

POM is the Project Object Model, the fundamental unit of work in Maven. It is an XML file containing information about the configuration details and the Project that Maven uses for building the projects.

What is the use of Maven GroupID?

GroupID is the unique identifying feature of all the Projects that starts from a reversed Domain. Maven does not enforce this convention, as there are multiple projects where the pattern is broken.

What is ArtifactID?

Artifact ID is the name of .JAR file without the version. If we are creating the JAR File, we can name the ArtifactID however we like.

What is Spring Boot?

Spring Boot is a Java Based Open Source Framework that is used to create a microservice. It is also used to build Standalone Production Ready Spring Applications.

Conclusion

In this article, we discussed what Maven GroupID is, along with some functionalities offered by the use of Maven GroupID and some differences between GroupID and Artifact ID.

Also, check out the following blogs:

• Maven Interview Questions
• DropWizard - Setting up using Maven
• How to install Maven on Windows
• Maven Artifact
   

Also, check out some of the Guided Paths on topics such as Data Structures and Algorithms, Competitive Programming, Basics of Java, etc., as well as some Contests, Test Series, Interview Bundles, and some Interview Experiences curated by top Industry Experts only on Coding Ninjas Studio.