As some methods/classes are not available in older versions of Java, I have started checking the version installed in my libraries. The code is simple to add to the initialisation routine of the library.
Saves you having to answer questions as to why it doesn't work, when run on older versions.
B4X:
Public Sub Initialize
Dim ver As String = GetSystemProperty("java.version","0.0")
If ver.StartsWith("1.8") = False Then
Log("Sorry ????? library requires Java 8")
ExitApplication
End If
... rest of initialisation ...
End Sub
Saves you having to answer questions as to why it doesn't work, when run on older versions.