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这篇文章将为大家详细讲解有关java怎么为文件及文件夹添加权限,小编觉得挺实用的,因此分享给大家做个参考,希望大家阅读完这篇文章后可以有所收获。
/** * 增加权限,使路径可上传文件 */ public static void addChmod777(String filePath) throws IOException { if (!System.getProperty("os.name").startsWith("Win")) { String cmdGrant = "chmod 777 " + filePath; BaseLogMethod.logInfo(TAG, "File Augmentation after Moving:" + cmdGrant); Runtime.getRuntime().exec(cmdGrant); } } /** * 增加权限,使路径及子路径都有权限 */ public static void addRChmod777(String filePath) throws IOException { if (!System.getProperty("os.name").startsWith("Win")) { String cmdGrant = "chmod -R 777 " + filePath; BaseLogMethod.logInfo(TAG, ".addRChmod777: File Augmentation after Moving:" + cmdGrant); Runtime.getRuntime().exec(cmdGrant); } }
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
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: ALLOW
Permissions 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: ALLOW
Permissions 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: ALLOW
Permissions 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: ALLOW
Permissions 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: ALLOW
Permissions are:
WRITE_DATA
READ_DATA
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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