Auto-updater and launcher for your distributed applications. Built on top of Java 9's module system.

^{Downloads 4 files then launches hello-world.jar}

^{Downloads 4 files then launches hello-world.jar. You can see that subsequent runs won't download again.}

The update4j framework is the first auto-update and launcher framework completely compatible with Java 9. Easily host your application files anywhere in the cloud accesible via a URL (even Google Drive, Dropbox, Amazon S3, or Maven Central) and you can synchronize them with all your distributed applications.

Update4j has made security its priority. Signing your files is as easy as providing your private key to the framework on your dev machine, and it will do the job itself. On the client side, you should load the public key into the framework and it will automatically verify each and every downloaded file. It will forcefully reject any files without or with invalid signatures. This is an optional feature.

As a side feature, update4j allows you to make your application running as a single instance. Any new instance of the application would pass its command-line arguments to the existing running instance and shut down.

Download the JAR file from the latest release.

You can use it as a regular dependency, or you may run it as a runnable JAR file in modular mode. In the latter case you must also provide a Delegate in the module-path.

To run it as a runnable JAR as a module:

~$> java --module-path . --module org.update4j

Or in shorthand:

~$> java -p . -m org.update4j

Please refer to the documentation for a full reference guide.

The Javadoc is available here.

For frequently asked questions, please refer to the FAQ.

This project was highly influenced by edvin/fxlauncher. Thanks for the insights that made this possible.

This project is licensed under the Apache Software License 2.0