Your farmerswife (fw) system needs to be upgraded and running on version 6.5 or later in order to use "OpenJDK" instead of "Java (Oracle)."
NOTE: Since the Release of farmerswife v6.8 you need to at least run OpenJDK v11 on the fw Server app's host machine, in order for the Web Client and Mobile Web Client (and fwplay if licensed) to work.
Java only needs to be installed on the fw Server app host machine; it is used by the built-in web server and powers the Web Client and Mobile Web Client (and fw Play if licensed).
We recommend manually keeping OpenJDK up to date. If it auto-updates while the fw Server app is running, then the Web Client and Mobile Web Client can't be used until the fw Server app is restarted. You should first Quit the running fw Server app, then update OpenJDK and then launch the fw Server app again.
1. First UNINSTALL ALL previous Java versions - especially the old deprecated v1.6, v1.7 and v1.8 - on the fw Server host machine; you might need to search for uninstall instructions.
It can help to use the Windows Task Manager or Activity Monitor on Mac to ensure that no "Java" process is still running.
Only then Install OpenJDK.
2. Download OpenJDK e.g. here:
Since 2022 this has been rebranded to this: https://adoptium.net
Use the "Hotspot" version.
The installers are called for example:
On Windows: OpenJDK8U-jdk_x64_windows_hotspot_11.0.13_8.msi
On Mac: OpenJDK8U-jdk_x64_mac_hotspot_11.0.13_8.pkg
On Linux: OpenJDK8U-jdk_x64_linux_hotspot_11.0.13_8.tar.gz
Note: The version numbers above may have changed since the creation of this article. You can always use the latest release.
Update July 25th, 2022:
The latest "LTS" Hotspot version is now 11.0.16+8
⚠️ This is IMPORTANT in relation to the "log4j" exploit! Ensure you have at least "LTS" Hotspot version 11.0.1 installed. Please use the latest 18.104.22.168+1!
See more info on the "log4j" issue here: "log4j" exploit and farmerswife
We are using this on our side, and we recommend you do the same on yours.
3. After launching the fw Server application again, check e.g. that the Web Client is properly running.
Using the Windows Task Manager or Activity Monitor on Mac can help to ensure that now the "Java" process is running.
It is common that after installing Java or OpenJDK for the first time, the fw server may need to be fully shut down and restarted to recognize the installed java.
fw - farmerswife
JRE - Java Runtime Environment
JDK - Java Development Kit
LTS - Long Term Support