Running Eclipse IDE on Java 9

Update: Note that as of October 11/2017, Java 9 is 100% supported “out of the box” by Eclipse IDE, Oxygen Edition; Java 9 can be used to run your Eclipse IDE, Oxygen Edition, and can be used to build Java 9 applications without additional configuration. Download or update today.

Out of the box, Java 9 makes only a subset of the modules available to applications. If your application makes use of APIs from other modules, you need to configure the JVM to make those modules available. The Eclipse IDE its itself a Java application that uses APIs from modules outside of that default group, so a little extra configuration is needed to make it run on Java 9.

In your Eclipse IDE installation directory, you’ll find the eclipse.ini file that your Eclipse IDE uses for configuration information. Add --add-modules=ALL-SYSTEM after the -vmargs argument (basically anything that follows the -vmargs argument is passed to the VM at start up (note that most VMs will barf if you pass in arguments that they don’t know or expect; adding this option when running on a Java 8 JVM will result only in disappointment and frustration).

...
-vm
/path/to/jdk/bin
...
-vmargs
--add-modules=ALL-SYSTEM
...

There’s more information in the Eclipse wiki.

Note that we’re pushing out some updates to make it so that the modification is not required. But that will only apply on future versions of Eclipse IDE (e.g. the Oxygen point releases, Photon, and later). For all older versions of Eclipse IDE, you’ll need to make this configuration change.

If you want to learn more about Java 9 support in the Eclipse IDE, including the Java development tools (JDT) and other great features like Eclipse Web Tools, Eclipse Code Recommenders and Eclipse Maven Integration, etc., consider attending EclipseCon Europe in Ludwigsburg, Germany from October 24 – 26, 2017.

There’s an entire Java and JDT track that includes the following:

There will also be BoFs, along with all sorts of opportunities to network and learn.

EclipseCon Europe 2017

If you want to learn more about the great features available in the Eclipse IDE, follow @EclipseJavaIDE on Twitter (follow me while you’re at it).