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Publishing Your Own Open Source Project to Maven Central

A step-by-step guide to open-sourcing a Java project and publishing it to Maven Central using Sonatype OSSRH.

Publishing Your Own Open Source Project to Maven Central

A step-by-step guide to open-sourcing a Java project and publishing it to Maven Central using Sonatype OSSRH.

Victory

Introduction

After writing code for years and relying on third-party dependencies, many developers eventually start wondering:

What if others could use my own open source library one day?

Let’s start with something simple: extract a small project, open source it, and publish it to Maven Central so others can use it directly via Maven dependencies.

The biggest challenge for most people is not the publishing process itself—but figuring out what to build. This article walks through both the idea selection and the technical steps required to publish a project to Maven Central.

Choosing a Project Idea

Many developers want to open source something but don’t know where to start. That’s completely normal.

Instead of building a large and complex framework, the goal here is to experience the full release process. A great and simple starting point is:

Wrapping public APIs into Java SDKs

Many platforms provide HTTP-based APIs but do not offer official Java clients. This is an excellent opportunity to:

  • Practice API design
  • Provide real value to other developers
  • Publish a reusable library

Examples of platforms with public APIs:

  • WeChat
  • Pinterest
  • Weibo
  • Medium
  • Hacker News

Pick one that:

  • Does not already have a good Java SDK
  • Or has an implementation you believe can be improved
  • Or simply interests you

Versioning Strategy

Once development starts, version management becomes critical.

Semantic Versioning

Maven projects typically follow Semantic Versioning: MAJOR.MINOR.PATCH

  • MAJOR: incompatible API changes
  • MINOR: backward-compatible feature additions
  • PATCH: backward-compatible bug fixes

Additional qualifiers:

  • alpha – internal testing
  • beta – public testing
  • rc – release candidate
  • lts – long-term support

Reference: https://semver.org

GitHub Version Management

For small personal projects, GitHub tags are more than sufficient.

Each time you release a stable version to Maven Central, create a corresponding Git tag.

git tag -a 1.0.0 -m "First stable release"
git push origin 1.0.0

This allows users to easily map Maven versions to source code.

Preparing for Maven Central Publishing

Publishing to Maven Central requires using Sonatype OSSRH.

Step 1: Register a Sonatype Account

Sign up at: https://issues.sonatype.org

Step 2: Create a Jira Ticket

Create a ticket requesting permission to publish under your chosen groupId.

Important notes:

  • You must own or control the domain used in groupId
  • Alternatively, you can use:
    • com.github.username
    • io.github.username
  • After your first release, comment on the ticket to notify OSSRH
  • Once the ticket is marked RESOLVED, you may publish artifacts

Generating a GPG Key

Artifacts uploaded to Maven Central must be GPG signed.

Linux

Follow: https://central.sonatype.org/pages/working-with-pgp-signatures.html

Windows

Use Kleopatra: https://gpg4win.org/download.html

General steps:

  1. Create a new OpenPGP key pair
  2. Fill in personal information
  3. Set a passphrase
  4. Upload the public key to a key server

Updating pom.xml

Project Metadata

<licenses>
  <license>
    <name>The Apache License, Version 2.0</name>
    <url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
  </license>
</licenses>

<scm>
  <url>https://github.com/yourname/project.git</url>
  <connection>scm:git:https://github.com/yourname/project.git</connection>
</scm>

<developers>
  <developer>
    <name>yourname</name>
    <email>[email protected]</email>
  </developer>
</developers>

Build Plugins

Source and Javadoc artifacts are mandatory:

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-source-plugin</artifactId>
</plugin>

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-javadoc-plugin</artifactId>
</plugin>

Release Profile

Configure the release profile with:

  • Nexus staging plugin
  • Maven release plugin
  • GPG signing plugin

Maven settings.xml Configuration

<servers>
  <server>
    <id>oss</id>
    <username>SONATYPE_USERNAME</username>
    <password>SONATYPE_PASSWORD</password>
  </server>
</servers>

<profiles>
  <profile>
    <id>oss</id>
    <properties>
      <gpg.passphrase>YOUR_GPG_PASSPHRASE</gpg.passphrase>
    </properties>
  </profile>
</profiles>

Publishing Artifacts

Snapshot Release

<version>1.2.0-SNAPSHOT</version>
mvn clean deploy

Artifacts appear at: https://oss.sonatype.org/content/repositories/snapshots/

Release Version

<version>1.2.0</version>
mvn clean deploy -P release

After approval, artifacts become available on: https://mvnrepository.com

Conclusion

Publishing to Maven Central is not difficult, but it does require attention to detail.

Once completed, you gain:

  • A deeper understanding of Java build tooling
  • Experience with open source release workflows
  • A public artifact others can depend on

If you’ve ever considered open sourcing a project—this is the perfect place to start.

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