Package com.topjohnwu.superuser.nio

Class FileSystemManager

java.lang.Object

com.topjohnwu.superuser.nio.FileSystemManager

public abstract class FileSystemManager
extends Object

Access file system APIs.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	MODE_APPEND	For use with openChannel(java.lang.String, int): append to end of file while writing.
static final int	MODE_CREATE	For use with openChannel(java.lang.String, int): create the file if it doesn't already exist.
static final int	MODE_READ_ONLY	For use with openChannel(java.lang.String, int): open the file with read-only access.
static final int	MODE_READ_WRITE	For use with openChannel(java.lang.String, int): open the file with read and write access.
static final int	MODE_TRUNCATE	For use with openChannel(java.lang.String, int): erase contents of file when opening.
static final int	MODE_WRITE_ONLY	For use with openChannel(java.lang.String, int): open the file with write-only access.

Constructor Summary

Constructors

Constructor	Description
FileSystemManager()

Method Summary

Modifier and Type	Method	Description
final ExtendedFile	getFile(File parent, String child)
abstract ExtendedFile	getFile(String pathname)
abstract ExtendedFile	getFile(String parent, String child)
final ExtendedFile	getFile(URI uri)
static FileSystemManager	getLocal()	Get the FileSystemManager to access the file system of the current local process.
static FileSystemManager	getRemote(IBinder binder)	Create a FileSystemManager to access the file system of a remote process.
static Binder	getService()	Get the service that exports the file system of the current process over Binder IPC.
abstract FileChannel	openChannel(File file, int mode)	Opens a file channel to access the file.
final FileChannel	openChannel(String pathname, int mode)	Opens a file channel to access the file.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

MODE_READ_ONLY

public static final int MODE_READ_ONLY

For use with openChannel(java.lang.String, int): open the file with read-only access.

See Also:

• Constant Field Values

MODE_WRITE_ONLY

public static final int MODE_WRITE_ONLY

For use with openChannel(java.lang.String, int): open the file with write-only access.

See Also:

• Constant Field Values

MODE_READ_WRITE

public static final int MODE_READ_WRITE

For use with openChannel(java.lang.String, int): open the file with read and write access.

See Also:

• Constant Field Values

MODE_CREATE

public static final int MODE_CREATE

For use with openChannel(java.lang.String, int): create the file if it doesn't already exist.

See Also:

• Constant Field Values

MODE_TRUNCATE

public static final int MODE_TRUNCATE

For use with openChannel(java.lang.String, int): erase contents of file when opening.

See Also:

• Constant Field Values

MODE_APPEND

public static final int MODE_APPEND

For use with openChannel(java.lang.String, int): append to end of file while writing.

See Also:

• Constant Field Values

Constructor Details

FileSystemManager

public FileSystemManager()

Method Details

getService

@NonNull
public static Binder getService()

Get the service that exports the file system of the current process over Binder IPC.

Sending the Binder obtained from this method to a client process enables the current process to perform file system operations on behalf of the client. This allows a client process to access files normally denied by its permissions. This method is usually called in a root process, and the Binder service returned will be send over to a non-root client process.

You can pass this Binder object in multiple ways, such as returning it in the onBind() method of root services, passing it around in a Bundle, or returning it in an AIDL interface method. The receiving end will get an IBinder, which the developer should then pass to getRemote(IBinder) for usage.

getLocal

@NonNull
public static FileSystemManager getLocal()

Get the FileSystemManager to access the file system of the current local process.

getRemote

@NonNull
public static FileSystemManager getRemote(@NonNull
 IBinder binder)
                                   throws RemoteException

Create a FileSystemManager to access the file system of a remote process.

Several APIs are not supported through a remote process:

• File.deleteOnExit()
• FileChannel.map(FileChannel.MapMode, long, long)
• FileChannel.lock()
• FileChannel.lock(long, long, boolean)
• FileChannel.tryLock()
• FileChannel.tryLock(long, long, boolean)

Calling these APIs will throw UnsupportedOperationException.

Parameters:

binder - a remote proxy of the Binder obtained from getService()

Throws:

RemoteException - if the remote process has died.

getFile

@NonNull
public abstract ExtendedFile getFile(@NonNull
 String pathname)

See Also:

• File(String)

getFile

@NonNull
public abstract ExtendedFile getFile(@Nullable
 String parent,
 @NonNull
 String child)

See Also:

• File(String, String)

getFile

@NonNull
public final ExtendedFile getFile(@Nullable
 File parent,
 @NonNull
 String child)

See Also:

• File(File, String)

getFile

@NonNull
public final ExtendedFile getFile(@NonNull
 URI uri)

See Also:

• File(URI)

openChannel

@NonNull
public final FileChannel openChannel(@NonNull
 String pathname,
 int mode)
                              throws IOException

Opens a file channel to access the file.

Parameters:

pathname - the file to be opened.

mode - the desired access mode.

Returns:

a new FileChannel pointing to the given file.

Throws:

IOException - if the given file can not be opened with the requested mode.

openChannel

@NonNull
public abstract FileChannel openChannel(@NonNull
 File file,
 int mode)
                                 throws IOException

Opens a file channel to access the file.

Parameters:

file - the file to be opened.

mode - the desired access mode.

Returns:

a new FileChannel pointing to the given file.

Throws:

IOException - if the given file can not be opened with the requested mode.