listFiles() of File not working on symbolic links?

问题

I have the following File object pointing to a directory via symbolic link,

File directory = new File("/path/symlink/foo/bar");
String[] files = directory.listFiles();

listFiles() returns null, is this because of the symlink? if yes, how will I go about this if I really want to list the files in bar using the path that contains a symlink?

回答1:

According to what I've seen while Googling this puzzling behavior, Java requires that you call .getCanonicalFile() on a File whose path contains a link before you can use it in other file operations.

So:

File directory = new File("/path/symlink/foo/bar").getCanonicalFile();
String[] files = directory.listFiles();

回答2:

You could read the Symbolic LINK

回答3:

..extending what @mickthompson suggested, using the NIO File library (> Java 7) you can:

Path link = Paths.get("/path/symlink/foo/bar");
while (Files.isSymbolicLink(link)) {
    link = Files.readSymbolicLink(link);
}

Path[] files =  Files.list(link).toArray(size -> new Path[size]);

Path is easily converted to File so all your old Java IO code can be safely kept, @see Path#toFile().

回答4:

This is fixed for the 3.0.1 release. After that's released, give it a try and let us know if it's still a problem for you by opening a new bug, linking back to this one for context.

来源：https://stackoverflow.com/questions/2471805/listfiles-of-file-not-working-on-symbolic-links

标签

java

file-io

symlink