这篇文章主要介绍了如何使用java修改文件所有者及其权限,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下
1.设置所有者
管理文件所有者
Files.getOwner()和Files.setOwner()方法
要使用UserPrincipal来管理文件的所有者
（1）更改文件的所有者
import java.io.IOException;import java.nio.file.*;import java.nio.file.attribute.FileOwnerAttributeView;import java.nio.file.attribute.UserPrincipal;import java.nio.file.attribute.UserPrincipalLookupService;public class Main { public static void main(String[] args) { Path path = Paths.get("/www/test1.txt"); FileOwnerAttributeView foav = Files.getFileAttributeView(path, FileOwnerAttributeView.class); try { UserPrincipal owner = foav.getOwner(); System.out.format("Original owner of %s is %s%n", path, owner.getName()); FileSystem fs = FileSystems.getDefault(); UserPrincipalLookupService upls = fs.getUserPrincipalLookupService(); UserPrincipal newOwner = upls.lookupPrincipalByName("abc"); foav.setOwner(newOwner); UserPrincipal changedOwner = foav.getOwner(); System.out.format("New owner of %s is %s%n", path, changedOwner.getName()); }catch (IOException e){ e.printStackTrace(); } }}
输出
查看文件详细信息
2.ACL文件权限
Windows上支持ACL类型文件属性
使用AclFileAttributeView的
getAcl()方法获取文件的AclEntry列表
setAcl()方法设置文件的AclEntry列表
（1）读取文件e:/test1.txt的ACL条目
import java.io.IOException;import java.nio.file.Files;import java.nio.file.Path;import java.nio.file.Paths;import java.nio.file.attribute.AclEntry;import java.nio.file.attribute.AclEntryPermission;import java.nio.file.attribute.AclFileAttributeView;import java.util.List;import java.util.Set;public class Main { public static void main(String[] args) { Path path = Paths.get("e:/test1.txt"); AclFileAttributeView aclView = Files.getFileAttributeView(path, AclFileAttributeView.class); if (aclView == null) { System.out.format("ACL view is not supported.%n"); return; } try { List<AclEntry> aclEntries = aclView.getAcl(); for (AclEntry entry : aclEntries) { System.out.format("Principal: %s%n", entry.principal()); System.out.format("Type: %s%n", entry.type()); System.out.format("Permissions are:%n"); Set<AclEntryPermission> permissions = entry.permissions(); for (AclEntryPermission p : permissions) { System.out.format("%s %n", p); } } } catch (IOException e) { e.printStackTrace(); } }}
输出结果为
Principal: BUILTIN\Administrators (Alias)Type: ALLOWPermissions are:WRITE_DATA WRITE_OWNER APPEND_DATA SYNCHRONIZE WRITE_ATTRIBUTES EXECUTE READ_DATA DELETE_CHILD READ_ATTRIBUTES WRITE_NAMED_ATTRS WRITE_ACL DELETE READ_ACL READ_NAMED_ATTRS Principal: NT AUTHORITY\SYSTEM (Well-known group)Type: ALLOWPermissions are:WRITE_DATA WRITE_OWNER APPEND_DATA SYNCHRONIZE WRITE_ATTRIBUTES EXECUTE READ_DATA DELETE_CHILD READ_ATTRIBUTES WRITE_NAMED_ATTRS WRITE_ACL DELETE READ_ACL READ_NAMED_ATTRS Principal: NT AUTHORITY\Authenticated Users (Well-known group)Type: ALLOWPermissions are:WRITE_DATA READ_ATTRIBUTES APPEND_DATA WRITE_NAMED_ATTRS SYNCHRONIZE WRITE_ATTRIBUTES EXECUTE DELETE READ_DATA READ_ACL READ_NAMED_ATTRS Principal: BUILTIN\Users (Alias)Type: ALLOWPermissions are:READ_ATTRIBUTES SYNCHRONIZE EXECUTE READ_DATA READ_ACL READ_NAMED_ATTRS
（2）为指定用户添加新的ACL条目
e:/test1.txt为用户abc添加DATA_READ和DATA_ WRITE权限
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.*;import java.util.EnumSet;import java.util.List;import java.util.Set;import static java.nio.file.attribute.AclEntryPermission.READ_DATA;import static java.nio.file.attribute.AclEntryPermission.WRITE_DATA;public class Main { public static void main(String[] args) { Path path = Paths.get("e:/test1.txt"); AclFileAttributeView aclView = Files.getFileAttributeView(path, AclFileAttributeView.class); if (aclView == null) { System.out.format("ACL view is not supported.%n"); return; } try { UserPrincipal bRiceUser = FileSystems.getDefault() .getUserPrincipalLookupService().lookupPrincipalByName("abc"); Set<AclEntryPermission> permissions = EnumSet.of(READ_DATA, WRITE_DATA); AclEntry.Builder builder = AclEntry.newBuilder(); builder.setPrincipal(bRiceUser); builder.setType(AclEntryType.ALLOW); builder.setPermissions(permissions); AclEntry newEntry = builder.build(); List<AclEntry> aclEntries = aclView.getAcl(); aclEntries.add(newEntry); aclView.setAcl(aclEntries); }catch (IOException e){ e.printStackTrace(); } }}
输出结果比刚才多了
Principal: hkgi-PC\abc (User)Type: ALLOWPermissions are:WRITE_DATA READ_DATA
3.POSIX文件权限
UNIX支持POSIX标准文件属性
PosixFilePermission枚举类型定义九个常量，每个权限组件一个。
九个常数命名为X_Y，其中X是OWNER，GROUP和OTHERS，Y是READ，WRITE和EXECUTE。
PosixFilePermissions的toString()方法将一组PosixFilePermission枚举常量转换为rwxrwxrwx形式的字符串
PosixFileAttributeView的setPermissions()方法用来设置权限
（1）输出/www/test1.txt的权限
import java.io.IOException;import java.nio.file.Files;import java.nio.file.Path;import java.nio.file.Paths;import java.nio.file.attribute.*;import java.util.Set;public class Main { public static void main(String[] args) { Path path = Paths.get("/www/test1.txt"); PosixFileAttributeView posixView = Files.getFileAttributeView(path, PosixFileAttributeView.class); try{ PosixFileAttributes attribs = posixView.readAttributes(); Set<PosixFilePermission> permissions = attribs.permissions(); // Convert the file permissions into the rwxrwxrwx string form String rwxFormPermissions = PosixFilePermissions.toString(permissions); // Print the permissions System.out.println(rwxFormPermissions); }catch (IOException e){ e.printStackTrace(); } }}
输出结果
rw-r--r--
（2）读取和更新名为test的文件权限
import java.io.IOException;import java.nio.file.Files;import java.nio.file.Path;import java.nio.file.Paths;import java.nio.file.attribute.*;import java.util.EnumSet;import java.util.Set;import static java.nio.file.attribute.PosixFilePermission.*;public class Main { public static void main(String[] args) { Path path = Paths.get("/www/test1.txt"); PosixFileAttributeView posixView = Files.getFileAttributeView(path, PosixFileAttributeView.class); if (posixView == null) { System.out.format("POSIX attribute view is not supported%n."); return; } System.out.println("old:"); readPermissions(posixView); updatePermissions(posixView); System.out.println("new:"); readPermissions(posixView); } public static void readPermissions(PosixFileAttributeView posixView) { try{ PosixFileAttributes attribs; attribs = posixView.readAttributes(); Set<PosixFilePermission> permissions = attribs.permissions(); // Convert the set of posix file permissions into rwxrwxrwx form String rwxFormPermissions = PosixFilePermissions.toString(permissions); System.out.println(rwxFormPermissions); }catch (IOException e){ e.printStackTrace(); } } public static void updatePermissions(PosixFileAttributeView posixView) { try { Set<PosixFilePermission> permissions = EnumSet.of(OWNER_READ, OWNER_WRITE,OWNER_EXECUTE, GROUP_READ,GROUP_WRITE); posixView.setPermissions(permissions); System.out.println("Permissions set successfully."); }catch (IOException e){ e.printStackTrace(); } }}
输出结果
old:rw-r-----Permissions set successfully.new:rwxrw----
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本文标题: 如何使用java修改文件所有者及其权限
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