POSIX View

 1 package idv.steven.nio2.metadata;
 2 
 3 import java.io.IOException;
 4 import java.nio.file.Files;
 5 import java.nio.file.Path;
 6 import java.nio.file.Paths;
 7 import java.nio.file.attribute.GroupPrincipal;
 8 import java.nio.file.attribute.PosixFileAttributeView;
 9 import java.nio.file.attribute.PosixFileAttributes;
10 import java.nio.file.attribute.PosixFilePermission;
11 import java.nio.file.attribute.PosixFilePermissions;
12 import static java.nio.file.LinkOption.NOFOLLOW_LINKS;
13 import java.util.Set;
14 
15 public class POSIXView {
16 
17     public static void main(String[] args) {
18         PosixFileAttributes attr = null;
19         Path path = Paths.get("/home/steven/seal/steven.pub");
20         
21         // read permissions
22         try {
23             attr = Files.readAttributes(path, PosixFileAttributes.class);
24         } catch (IOException e) {
25             System.err.println(e.getMessage());
26         }
27 
28         System.out.println("File owner: " + attr.owner().getName());
29         System.out.println("File group: " + attr.group().getName());
30         System.out.println("File permissions: " + attr.permissions().toString());
31         
32         // set permissions
33         Set<PosixFilePermission> permissions = PosixFilePermissions.fromString("rw-r--r--");
34         try {
35             Files.setPosixFilePermissions(path, permissions);
36             
37             GroupPrincipal group = path.getFileSystem().
38                     getUserPrincipalLookupService().lookupPrincipalByGroupName("steven");
39                     Files.getFileAttributeView(path, PosixFileAttributeView.class).setGroup(group);
40                     
41             GroupPrincipal groupSteven = (GroupPrincipal) Files.getAttribute(path, "posix:group", NOFOLLOW_LINKS);
42             System.out.println(group.getName());
43         } catch (IOException e) {
44             System.err.println(e);
45         }
46     }
47 }

File owner: steven
File group: steven
File permissions: [OTHERS_READ, OWNER_WRITE, GROUP_WRITE, OWNER_READ, GROUP_READ]