在UNIX上使用NIO时未设置写权限

Question

I am using NIO to set permissions on all directories in a path as below. i am trying to give 777 permissions , however the "w" part is not getting applied...Whats wrong here?

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.FileAttribute;
import java.nio.file.attribute.PosixFilePermission;
import java.nio.file.attribute.PosixFilePermissions;
import java.util.Set;

public class permissionTest {

    public static void main(String [] args) throws IOException{

        Path dirPath = Paths.get("./part1/part2/part3");


        Set<PosixFilePermission> permissions = PosixFilePermissions.fromString("rwxrwxrwx");
        System.out.print(permissions.toString() + ' ');

        FileAttribute<Set<PosixFilePermission>> fileAttributes = 

                PosixFilePermissions.asFileAttribute(permissions);

        Files.createDirectories(dirPath, fileAttributes);

    }

}

$ ls -ld part1/
drwxr-xr-x 3 * *4096 Oct 30 02:48 part1/

Answer 1

This is because the umask is applied.

Try and type this at the shell:

umask 0

and then rerun your program (or launch your IDE from the command line and run the code). It also means that if you do umask 027 , the permissions for your created directories will be 750.

Unfortunately, you cannot change your process' umask (since this is per process, and inherited) in Java itself...

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Note that there is this method to set "absolute" file permissions.