How to install Java SDK 8 on Olimex Allwinner boards?
The installation had been tested with Olimex-made A13 and A20 boards running the official Debian. More specifically, the boards used during testing were A20-OLinuXino-MICRO and A13-OLinuXino-WIFI.
Installing JDK via the graphical interface
1. Boot the board with the default image. Open a browser and navigate to Oracle's website. Download the archive "Java SE Development Kit 8 Update XX for ARM". It is important the release you download is suitable for Linux ARM v6/v7 Hard Float ABI. At the time of writing the resource is available here: JDK 8 ARM.
You can also do this while the board is offline in that case download the archive to your personal computer and transfer it to the microSD card with the board's Debian. Then boot the board with the card that contains the downloaded archive.
2. Update the Debian
3. Upgrade the Debian
4. Extract the archive to /opt/JDK
5. Export PATH=$PATH:/opt/JDK/JDK.8.0.3/bin
6. The Java JDK 8 is now successfully installed.
Testing the JDK:
1. Navigate to the same web-page where you downloaded the SDK at the Oracle's web-site. Below the SDK there is an archive containing demos and examples. Download it to the microSD card.
2. Extract it.
3. Start the Java that we installed previously.
4. Load a demo. For example, navigate to \demo\jfc\Java2D and load Java2Demo.jar
Note that Java SDK consumes significant CPU power. It might consume up to 30% CPU.