问题
I thought this would be an easy task but . . . I want my Java program to get the user's Windows file associations. In other words, I want to know what the user uses to open .txt files, .cvs files, etc. The assoc and ftype commands provide that info, but not for the user. In other words, if I've set my text editor to Notepad++, assoc and ftype don't show it. They show the system default, Notepad, instead. It looks like I have to get that info from the registry but I have two problems. 1) I don't know the exact registry keys I want to pull (though I've looked at "reg query HKEY_CURRENT_USER, HKEY_CLASSES_ROOT, etc.) 2) I don't know how to pull the key from the registry. I've seen JNI mentioned but haven't figured out the details. Any hints appreciated.
回答1:
In Win7, you can find the "class"* for each file extension in the
HKLM\SOFTWARE\Classes\<extension>\(Default)
key.
For example, on my machine
HKLM\SOFTWARE\Classes\.txt
has a (Default) key of txtfile.
In that same path, you can find what opens files of the class txtfile:
HKLM\SOFTWARE\Classes\txtfile
Which should have a subpath of ...\shell\open\command
On my system,
HKLM\SOFTWARE\Classes\txtfile\shell\open\command\(Default)
is
%SystemRoot%\system32\NOTEPAD.EXE %1
Which you could parse to find the executable that opens .txt files.
For user-specific customizations, you can replace
HKLM\SOFTWARE\Classes\
with
HKCU\Software\Classes\
All that being said, I like MadProgrammer's suggestion if possible for your application.
* I'm sure there is a better name for "class", I just don't know it.
回答2:
Take a look at the Eclipse's Program class, which should to what you want: http://help.eclipse.org/helios/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Freference%2Fapi%2Forg%2Feclipse%2Fswt%2Fprogram%2FProgram.html.
If you would like to launch the program, use the Desktop-class (like MadProgrammer suggested)
来源：https://stackoverflow.com/questions/13576124/get-windows-files-associations-via-java