很简单，调用explorer.exe就可以，
Runtime.getRuntime().exec(
"rundll32 SHELL32.DLL,ShellExec_RunDLL " +
"Explorer.exe /select," + targetDirectFileName);
[Windows Explorer Switches]
Windows Explorer switches are useful in creating rooted folders:
Explorer [/e][,/root,<object>][[,/select],<sub object>]
/e
Use Explorer view (scope and results pane view). The default is
Open view (results in pane view only).
/root<object>
Specify the object in the "normal" name space that is
used as the root (top level) of this Explorer/Folder (i.e., local
path or UNC name). The default is the Desktop).
/Select
The parent folder opens and the specified object is selected.
<sub object> Specify the folder unless /select is used. The
default is the root.