Previously I am developing applications with JavaFX in Oracle Java SE shipped by Red Hat but it seems it is no longer offered as in https://access.redhat.com/articles/3253281. However, it seems that the OpenJDK coming from rhel-7-server-rpms repository does not come with JavaFX.
Are there better ways instead of just installing packages from outside the repositories provided by Red Hat? I don't want to test each environment with self-compiled OpenJFX binary one by one.
Oracle provide RPMs you can download:
Those RPMs are not in a YUM repository that you could just point your red hat boxes to.
You can download the RPMs and create your own rum repository, then add your custom repository to the yum repository list for each of your target machines and after that use yum to install the rpms to your boxes. You would need to restrict this so that it isn't fully open to the public I think (to meet Oracle Java distribution requirements).
If you built your own version of the Java SE which included JavaFX from OpenJFX sources (or you can find a package for your target OS which somebody else has built), then you could host that in an unrestricted manner in your own repository (or any other public repository out there), or pull the package from a public repository if somebody else has already put it there.
If you don't need a repository, and can just scp the rpms to the relevant machines then you can directly install the rpms on the machines without setting up your own custom repository.
If you package your application as a self-contained application, then the application install bundle itself will include the JRE, so you don't need to worry about installing that separately on the machine (and also don't potentially run into situations where the user has installed a runtime version which is not compatible or tested with your code). Perhaps that is a preferred path for you.
I don't know RedHat's policy for OpenJDK releases and builds to their repositories. It would be nice if they included JavaFX in their OpenJDK distributions in their repositories or provided a separate package for OpenJFX, similar to what Ubuntu do. Perhaps they might include JavaFX in their OpenJDK 9 distributions. They have info on RHEL Support for OpenJDK 9, so maybe they say something there (I can't read it as I am not a RHEL subscriber). If you have a support contract with Redhat and the info isn't available on their site, then you could ping them and ask them about OpenJFX JavaFX distributions hosted in their repository (to see if they are there or not or if they have a plan to put them there).