DLL issue with Win7 64bit and Java interface

[jb747]

Hi Pete,

I have a software interface to FSUIPC using Java to run my motorized power quadrant in the B747 (throttles and spoiler) and works well with XP 32-bit. However, when trying to activate the interface module on a Win7 64-bit computer the diagnistics indicate that the FSUIPC_java.dll isn't found and the program stalls. In XP I dropped a copy of the DLL into the Windows System32 folder and everything worked fine. I did the same here and it's a non-starter. Is there some other dll that I need to connect with the new computer? There is only the one dll in the Jave SDK folder.

Thanks,

Jon

[Pete Dowson]

Why did you post a support question into the Announcements forum? Please don't do things like that! You are lucky I saw it!

I have a software interface to FSUIPC using Java to run my motorized power quadrant in the B747 (throttles and spoiler) and works well with XP 32-bit. However, when trying to activate the interface module on a Win7 64-bit computer the diagnistics indicate that the FSUIPC_java.dll isn't found and the program stalls. In XP I dropped a copy of the DLL into the Windows System32 folder and everything worked fine. I did the same here and it's a non-starter. Is there some other dll that I need to connect with the new computer? There is only the one dll in the Jave SDK folder.

Sorry, I don't understand muchof that at all. What is supposed to be accessing your DLL? I've got nothing in FSUIPC which knows anything about your DLLs.

The search pattern used by Windows to find referenced DLLs is pretty much the same across the board with different Windows versions as far as I know, but generally I keep my DLLs along with the program which is using them. I think Windows can also look in its own folder (C:\Windows for instance), but they can be in any folder you like if the program loading them uses the full path to them.

The other thing to bear in mind with Win7 is that many of the folders are protected against being written to by users -- the folders you see are often aliassed, not the real ones, to protect program and system files. You can get around this by running Explorer by right-clicking on it and selecting "run as ... administrator". That runs it at an elevated administrator level, not the normal administrator level, and it can then write to more places.

Pete

[Paul Henty]

on a Win7 64-bit computer the diagnistics indicate that the FSUIPC_java.dll isn't found and the program stalls. In XP I dropped a copy of the DLL into the Windows System32 folder and everything worked fine. I did the same here and it's a non-starter.

Further to Pete's suggestions, here are two more things you can try:

Try copying the FSUIPC_java.dll into C:\windows\SysWOW64. The C:\windows\system32 folder is only used for 64 bit applications. 32 bit applications (like the Java dll) need to be in the C:\windows\SysWOW64 folder. Windows make this look like C:\windows\system32 to all 32 bit processes. (Yes, the names are counter intuitive).

Also, check that your application that links the DLL is being compiled as a 32bit binary. If it's compiled as a 64bit (or dual-format) binary then it will be running in a 64 bit process and will not be able to link the 32bit FSUIPC_java.dll.

Paul

[jb747]

Thanks for the suggestions.

I got everything functional by moving the FSUIPC_Java.dll to the SysWOW64 directory as suggested as well as running the Java application in 32-bit format. Stupid me.

However, I had to make one other change to drive the Tomcat application in the Environmental Variables from C:\Program Files(x86)\Java....

to C:\Progra~2\Java...

That change was not as obvious.

Thanks again

Jon