Java 9 / JavaFX Open URI Issue

Supplemental information for https://bugs.java.com/bugdatabase/view_bug.do?bug_id=JDK-8198549

The issue is that if your app is registered for a URI scheme, the app must already be running, otherwise it will not receive the event through the event handler set via Desktop.setOpenURIHandler. If the app is not running yet, it will be launched, but the URI that caused the launch is lost, rendering the feature useless.

How to build

This projects needs to be built on a Mac with JDK 9. You can just run build.sh.

The steps in the build file are illustrated here for clarity:

Enforce Java 9 on Mac, clean output directories and compile application into class files:

$ export PATH=`/usr/libexec/java_home -v9`/bin:$PATH
$ rm -rf classes/* jar/* dist/*
$ javac -d classes src/com/example/Main.java

Create JAR file using javapackager:

$ javapackager -createJar -appclass com.example.Main -outdir jar -outfile example -srcdir classes

Create Mac app bundle using javapackager (required for registering app with a URI scheme).

Note that we override Info.plist with our own, containing the CFBundleURLKeys (-BdropinResourcesRoot=.)

Code signing is not required for this example to work, but you might have to allow running the app via system security settings.

$ javapackager -deploy -verbose -native image -name "Open URI Example" -srcdir jar -appclass com.example.Main \
    -outdir dist -outfile Example \
    -Bmac.CFBundleIdentifier=com.example.openuri -Bmac.CFBundleVersion=1.0.0 \
    -nosign \
    -BdropinResourcesRoot=.

How to test

Open the app via Terminal:

$ open javafx-openuri://hello

Or via a web browser:

<a href="javafx-openuri://hello">Open Application</a>

If it is not running, it will display No URI opened which illustrates the bug.

If the app is running, it will display the URI correctly.