The `java.awt.SystemTray` API is used for notifications in a desktop taskbar and may include an icon representing an application. On Linux, the Gnome desktop's own icon support in the taskbar has not worked properly for several years due to a platform bug. This, in turn, has affected the JDK's API, which relies upon that.
Therefore, in accordance with the existing Java SE specification, `java.awt.SystemTray.isSupported()` will return false where ever the JDK determines the platform bug is likely to be present.
The impact of this is likely to be limited since applications always must check for that support anyway. Additionally, some distros have not supported the SystemTray for several years unless the end-user chooses to install non-bundled desktop extensions.