Nadron is a Java NIO based server specifically designed for multiplayer games. It supports UDP and TCP transports. It uses Netty 4.1 for high speed network transmission and Jetlang for extremely fast in-VM message passing between player sessions and game rooms. The project uses Spring Framework 6 for dependency injection, making it highly configurable so you can swap out any part of the server with your own implementations.

Technology Stack

• Java 17 LTS - Modern, long-term support release
• Netty 4.1.115 - High-performance async network framework
• Spring Framework 6.2.0 - Dependency injection and application context
• Jackson 2.18.1 - JSON serialization
• JUnit 5.11.3 - Modern testing framework
• Log4j 2.24.2 - Secure, modern logging
• SLF4J 2.0.16 - Logging abstraction

Wiki

The wiki provides implementation level details and answers to general questions that a developer starting to use Nadron server might have about it. This blog post contains a decent tutorial on creating a multiplayer game using this server. Support Group

For general discussion please use the Nadron server google group. Issues and bugs can be raised directly in github.

Requirements

• Java 17 or later - The project uses Java 17 LTS features
• Maven 3.8+ - For building the project

Installation

Maven

<dependency>
    <groupId>com.github.menacher</groupId>
    <artifactId>nadron</artifactId>
    <version>0.8-SNAPSHOT</version>
</dependency>

Building from Source

Prerequisites:

• Java 17 JDK or later
• Maven 3.8 or later
• Git

Steps:

1. Clone the repository:

   git clone git@github.com:menacher/java-game-server.git
   cd java-game-server/nadron
   

2. Build the project:

   mvn clean install
   

3. Run tests:

   # Run regular tests (excludes performance tests)
   mvn test
   
   # Run performance tests
   mvn test -Pperformance
   

4. The built JAR will be in target/nadron-0.8-SNAPSHOT.jar

IDE Setup

IntelliJ IDEA / Eclipse / VS Code:

• Simply import as a Maven project
• The IDE will automatically download dependencies
• Make sure your project SDK is set to Java 17+

For Eclipse users:

mvn eclipse:eclipse

Then import the project via File → Import → Existing Projects into Workspace

Performance

The modernized Nadron server delivers excellent performance on Java 17:

• Message passing rate: Up to 40+ million messages/sec between sessions
• Event dispatching: 5 million events in ~0.6 seconds
• Session communication: 10-40 million messages/sec depending on configuration

Testing

The project includes comprehensive unit tests using JUnit 5:

• 13 regular tests - Fast unit tests that run with every build
• 4 performance tests - Tagged separately for performance benchmarking

Happy coding!