Solved - Java 8u101 update blocked by windows firewall

[skeptic Mike]

(16-02-2017 18:59)MarmiteSandwich Wrote:  I have this problem where each update to java installs itself in a new folder e.g. C:\Program Files (x86)\Java\jre1.8.0_121\bin. But the Windows firewall is only allowing the version of Java through which lives in C:\Program Files (x86)\Java\jre1.8.0_25\bin. So every time there is a Java update, there is a prompt for me to allow this "new" program through the firewall. Since Minimserver is running on a server which I am generally not logged onto, the first I know about this is that Minimserver is greyed out. Is there some simple fix to make the Firewall allow ALL versions of Java through, wherever they live?

Oracle have a rather strange way of organising Java on Windows so that you can run Java programs reasonably easily. If you run Java by starting a jar file through the file association, then you start Java in the directory in which it's installed, e.g. you actually run C:\Program Files (x86)\Java\jre1.8.0_121\bin\javaw.exe, if you start it from the command line by just typing e.g. javaw -jarfile myprogram.jar, then it starts the version in the path. Since Java 8 was released, this has been the javaw.exe file in c:\ProgramData\Oracle\Javapath, which is in the system path. Normally this makes no difference to anything, but if you have a firewall exception for any executable file such as javaw.exe, then windows uses the full path name to identify it.

Now, when you update Java, the main installation goes in a new folder, but the copies of javaw.exe, and java.exe in the c:\ProgramData\Oracle\Javapath folder are also updated. So, you could use that file instead. To do that you'd have to start MinimServer either by using the javaw -jarfile invocation, or, if you wanted to start from the start menu, you'd have to edit the shortcut.
You'd then have to edit the firewall entries to reflect the different Javaw path, but it wouldn't change when you updated the Java installation.

If you want to run MinimServer as a windows service, and use a regular Java installation which you'll update, then you'll want to use the java.exe in the path. There are some instructions elsewhere in this forum that I wrote on how to run MinimServer as a windows service in a reasonably safe and secure way. I used an entirely private Java installation in the example that I gave, so I didn't deal with this point. On my list of things to do at some point is to write this up as a tutorial, but I haven't yet done this. My assumption is that most people use a NAS, or linux server as their main music server, so this is very much of minority interest. I'll probably move to a linux server at some point, but I think it is worth describing the method for windows.