Switch branches/tags
Clone or download

Grizzly NIO

Writing scalable server applications in the Java™ programming language has always been difficult. Before the advent of the Java New I/O API (NIO), thread management issues made it impossible for a server to scale to thousands of users. The Grizzly NIO framework has been designed to help developers to take advantage of the Java™ NIO API. Grizzly’s goal is to help developers to build scalable and robust servers using NIO as well as offering extended framework components: Web Framework (HTTP/S), WebSocket, Comet, and more!

Getting Started

Grizzly currently has several lines of development in the following branches:

  • 2.3.x : This is the sustaining branch for 2.3. (latest release is 2.3.33)
  • master : This is the sustaining branch for the most recent major release of Grizzly. (latest release is 2.4.2)
  • 3.0.x : This is our upcoming 3.0 release. Fair warning; it's not backwards compatible with previous releases.

There are other branches for older releases of Grizzly that we don't actively maintain at this time, but we keep them for the history.


We have different JDK requirements depending on the branch in use:

  • Oracle JDK 1.8 for master and 3.0.x branches.
  • Oracle JDK 1.7 for 2.3.x.

Apache Maven 3.3.9 or later in order to build and run the tests.


See for the maven coordinates of the 2.3.x release artifacts.

If building in your local environment:

mvn clean install

Running the tests

mvn clean install


This project is licensed under the EPL-2.0 - see the LICENSE.txt file for details.