问题
Is there any mechanism to get and set the file/directory permissions?
For example, I want to show the permisssions of a file in a shell way:
-rwxr-xr--
Is it possible to do this using Java?
- I know that there are some methods in the
File
class to know if the filecanExecute
,canRead
andcanWrite
, but AFAIK this info is for the current user only. I need to know the whole octal number, for example 755, so I need to get it from the user, from group and from others. - I know that Java7 brings Posix operations, but how could do this using a smaller JRE?
- I would like not to use a command like
ls
, orchmod
.
回答1:
If you can use external libraries, there are several:
- JPosix
- Posix for java
- jnr-posix
If an entire library seems a hassle, creating a JNI wrapper that calls the lstat
C function and returns the access mode takes you about 10 minutes. Here's a tutorial that creates such a wrapper for the isatty and ttyname functions.
回答2:
As you say, in Java7, the JVM supports it, so you have a guarantee that this can be done portably in all OSs (because the JVM implementation takes care of it). Under Java7, you'd have to use a native library per OS you want to support. This is potentially even dirtier than executing chmod
来源:https://stackoverflow.com/questions/15568629/how-to-manage-linux-file-permissions-in-java