Hello,
I a going to be doing that very thing over this weekend. I have changed over to Silverblue from standard Fedora Workstation, due to the promise of easier development through the flatpak/container model. So far I am not at the point of installing Java, which I assume has to be layered if I want it available to any faltpak. I gave up, temporarily on trying to get Evolution installed as a flatpak, since currently faltpak-builder will not install into the ostree (I am using F28). As I get to the install, I’ll have more info that I can share about using Oracles JDK 8 and 10 on Silverblue. From the info up top it appears that Oracle installer is pointing to the wrong location for basename perhaps. You could try to modify their install script.
This is saying that nothing provides /bin/basename. As you have pointed out in fedora it is located at /usr/bin/basename. Unfortunately the RPM provided by Oracle on the Java site doesn’t account for this.
Would openJDK suffice? you could try rpm-ostree install java-1.8.0-openjdk in that case.
Installing things on the host won’t (usually) change what appears in flatpaks - both flatpak
and Docker/OCI containers have their own “base image” model that’s completely
separate from the host. Though flatpak does have extension points.
If you need the JRE for non-graphical applications (e.g. you’re developing a
Kubernetes app using Kotlin or something), then you want the JRE from a base
image.