Software Prerequisites

Java 8 and the Latest JavaFX APIs

This project requires Java 8 and specifically the JavaFX API version introduced with Java SE build 1.8.0u40. The latest version of Raspbian comes with Java 8, but unfortunately it does not include the latest JavaFX APIs.

The good news is that an overlay is available. The overlay updates the built-in JavaFX APIs to the latest.

OpenJDK Overlay of JavaFX APIs

A good old chap, by the name of Chris Newland, has provided the latest OpenJDK JavaFX APIs as an overlay for the Java SE Runtime Environment that ships with Raspbian.

If you want the nightly build, then head over to http://108.61.191.178/ and select a 'nightly' build from the options under Download OpenJFX builds for Linux ARMv6 hard float (Raspberry Pi etc.).

Otherwise, download this local copy of the 'OpenJFX 8u40 stable for armv6hf' overlay:

 

When the download for the overlay is complete, copy it (the whole zip file) to the Raspberry Pi.

Log into the Raspberry Pi, as the pi user.

At this point, you are logged into the Raspberry Pi. Now we need to find the destination for the overlay; that is the directory of the Java Runtime on the filesystem.

On the Pi used for this project, you can see below that java really points to /usr/lib/jvm/jdk-8-oracle-arm-vfp-hflt/jre/bin/java

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[email protected]:~ $ which java
/usr/bin/java

[email protected]:~ $ ls -la /usr/bin/java
lrwxrwxrwx 1 root root 22 Nov 21 20:54 /usr/bin/java -> /etc/alternatives/java

[email protected]:~ $ ls -la /etc/alternatives/java
lrwxrwxrwx 1 root root 51 Nov 21 20:54 /etc/alternatives/java -> /usr/lib/jvm/jdk-8-oracle-arm-vfp-hflt/jre/bin/java

From the information above, the following is used for the destination of the OpenJDK JavaFX APIs overlay.

  • /usr/lib/jvm/jdk-8-oracle-arm-vfp-hflt/

Next, change directory to where the overlay ZIP file was copied.

Issue this command to perform the overlay:

Download: file
sudo unzip openjfx-8u40-sdk-overlay-linux-armv6hf.zip -d /usr/lib/jvm/jdk-8-oracle-arm-vfp-hflt/

Inflating messages are printed next. Answer 'A' to confirm replacement of existing files.

If no error messages are shown, then the overlay is complete :)

This guide was first published on Nov 28, 2015. It was last updated on Nov 28, 2015. This page (Software Prerequisites) was last updated on Oct 30, 2019.