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這篇文章將為大家詳細講解有關java怎么為文件及文件夾添加權限，小編覺得挺實用的，因此分享給大家做個參考，希望大家閱讀完這篇文章后可以有所收獲。
/**
* 增加權限，使路徑可上傳文件
*/
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);
}
}
/**
* 增加權限，使路徑及子路徑都有權限
*/
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來管理文件的所有者
（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();
}
}
}輸出
查看文件詳細信息
Windows上支持ACL類型文件屬性
使用AclFileAttributeView的
getAcl()方法獲取文件的AclEntry列表
setAcl()方法設置文件的AclEntry列表
（1）讀取文件e:/test1.txt的ACL條目
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();
}
}
}輸出結果為
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）為指定用戶添加新的ACL條目
e:/test1.txt為用戶abc添加DATA_READ和DATA_ WRITE權限
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();
}
}
}輸出結果比剛才多了
Principal: hkgi-PC\abc (User)
Type: ALLOW
Permissions are:
WRITE_DATA
READ_DATA
UNIX支持POSIX標準文件屬性
PosixFilePermission枚舉類型定義九個常量，每個權限組件一個。
九個常數命名為X_Y，其中X是OWNER，GROUP和OTHERS，Y是READ，WRITE和EXECUTE。
PosixFilePermissions的toString()方法將一組PosixFilePermission枚舉常量轉換為rwxrwxrwx形式的字符串
PosixFileAttributeView的setPermissions()方法用來設置權限
（1）輸出/www/test1.txt的權限
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();
}
}
}輸出結果
rw-r--r--
（2）讀取和更新名為test的文件權限
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();
}
}
}輸出結果
old:
rw-r-----
Permissions set successfully.
new:
rwxrw----
關于“java怎么為文件及文件夾添加權限”這篇文章就分享到這里了，希望以上內容可以對大家有一定的幫助，使各位可以學到更多知識，如果覺得文章不錯，請把它分享出去讓更多的人看到。
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