Example of UserPrincipal in Java NIO
December 12, 2013
UserPrincipalLookupService in Java NIO
java.nio.file.attribute.UserPrincipalLookupService is the part of JDK 7 and is an NIO API. To get UserPrincipal , UserPrincipalLookupService provides the methods that is based by name or by group name. These methods arelookupPrincipalByGroupName() : It accepts account name and returns GroupPrincipal. It is used to look up groups of users.
lookupPrincipalByName() : It accepts user name and returns UserPrincipal. It is used to look up user. In our example we will use lookupPrincipalByName().
Files.setOwner() in Java NIO
setOwner() is the method of java.nio.file.Files. This method sets and updates the owner of a file. It accepts the Path and UserPrincipal as owner.Files.getOwner() in Java NIO
getOwner() is the method of java.nio.file.Files. We pass the file path and it returns UserPrincipal. In this way with the help of getOwner(), we can get the information of a file.UserPrincipalExample.java
package com.concretepage.io.file.attribute;
import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.UserPrincipal;
import java.nio.file.attribute.UserPrincipalLookupService;
public class UserPrincipalExample {
public static void main(String[] args) throws IOException {
Path file = Paths.get("D:/cp","UserPrincipalLookupServiceExample.java");
UserPrincipalLookupService lookupService = FileSystems.getDefault().getUserPrincipalLookupService();
UserPrincipal owner = lookupService.lookupPrincipalByName("arai");
Files.setOwner(file, owner);
UserPrincipal userPrincipal = Files.getOwner(file);
System.out.println(userPrincipal.getName());
}
}
