Solved - Java 8u101 update blocked by windows firewall

[Glandwr]

Thank you, I'll try that

[Glandwr]

Thank you Houston, we are Green for Minimwatch (for now anyway!).

BTW
You may not have a synology NAS but I'm stopping Minimserver via the Package Centre - is there a better way to stop it?

[simoncn]

(16-08-2016 09:37)Glandwr Wrote:  Thank you Houston, we are Green for Minimwatch (for now anyway!).

BTW
You may not have a synology NAS but I'm stopping Minimserver via the Package Centre - is there a better way to stop it?

There is no need to stop/restart MinimServer on the NAS because of a Windows firewall issue.

If for any reason you do need to stop MinimServer on the NAS, the Package Center is the correct way to do it.

[Glandwr]

Thank you sir. While I have your attention, I suppose Sony Songpal is totally incompatible with Minimserver, or sso little used it's not worth all the extra coding?

I'm very pleased with this over the Synology Media server, and my previous Twonky (had some fun with that...)

[MarmiteSandwich]

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?

[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.

[MarmiteSandwich]

(17-02-2017 01:29)skeptic Mike Wrote:  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.

Quote: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.

Thanks for the comprehensive response, skeptic Mike. I have tried this with limited success. Firstly, when I open c:\ProgramData\Oracle\Javapath, I see 3 files, java.exe, javaw.exe and javas.exe. Each of these is a Windows shortcut (well, symlink actually), which points to the equivalent file in the update version bin folder, which I saw as a bad sign. Anyway, in order to run minimserver at startup, I have tried replacing a shortcut to "C:\Program Files\MinimServer\lib\mserver.jar" in the Windows startup folder with a batch file containing the command javaw -jarfile "C:\Program Files\MinimServer\lib\mserver.jar". When I attempt to execute this batch file, I get the Java Virtual Machine Launcher error "Could not create the Java Virtual Machine". I have checked the path and it does include c:\ProgramData\Oracle\Javapath. I also tried locating the batch file in the Minimserver\lib folder without success. Then I got a bit stuck, not knowing how Java works. Any further suggestions welcome.

[simoncn]

The syntax is javaw -jar myprogram.jar, not javaw -jarfile myprogram.jar.

[MarmiteSandwich]

Thanks for that, Simon. Changing the target in the Windows shortcut which lives in the startup folder to C:\ProgramData\Oracle\Java\javapath\javaw.exe -jar "C:\Program Files\MinimServer\lib\mserver.jar" was successful, in that Minimserver runs as before. The bad news is that the Windows Firewall dialog, which should appear when Minimserver starts up, to allow this new location of javaw.exe, does not appear, as skeptic Mike said it would.

Quote:You'd then have to edit the firewall entries to reflect the different Javaw path

In other words, as far as the firewall is concerned, the version of java which is now running is still the one in C:\Program Files (x86)\Java\jre1.8.0_121\bin, or else the firewall would be blocking it. I proved this by editing the firewall entries for the version of java in C:\Program Files (x86)\Java\jre1.8.0_121\bin, so that they were replaced by the location C:\ProgramData\Oracle\Java\javapath. Then I get the firewall dialog asking to allow the version in C:\Program Files (x86)\Java\jre1.8.0_121\bin.

So I don't seem to be any further forward. If you run Javaw in the generic Oracle\Javapath folder, the program which Windows runs is still in the update specific folder, which changes every time there is a Java update.

[simoncn]

You could copy the real javaw.exe into C:\ProgramData\Oracle\Java\javapath, overwriting the symbolic link. You would need to do this every time you install a Java update but this might perhaps be easier than updating firewall rules.