java|java 如何为文件及文件夹添加权限 java如何为文件及文件夹添加权

java 为文件及文件夹添加权限
java 修改文件所有者及其权限

1.设置所有者
2.ACL文件权限
3.POSIX文件权限

java 为文件及文件夹添加权限

/** * 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); }}

java 修改文件所有者及其权限
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

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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 ownerof%sis %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 ownerof%sis %s%n", path,changedOwner.getName()); }catch (IOException e){e.printStackTrace(); }}}

输出

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查看文件详细信息

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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 viewis notsupported.%n"); return; }try {List 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 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 viewis notsupported.%n"); return; }try {UserPrincipal bRiceUser = FileSystems.getDefault().getUserPrincipalLookupService().lookupPrincipalByName("abc"); Set 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 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

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 permissions = attribs.permissions(); // Convert the file permissions into the rwxrwxrwx string formString rwxFormPermissions = PosixFilePermissions.toString(permissions); // Print the permissionsSystem.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 viewis notsupported%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 permissions = attribs.permissions(); // Convert the set of posix file permissions into rwxrwxrwx formString rwxFormPermissions = PosixFilePermissions.toString(permissions); System.out.println(rwxFormPermissions); }catch (IOException e){e.printStackTrace(); }}public static void updatePermissions(PosixFileAttributeView posixView) {try {Set 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