ParcelFileDescriptor
open class ParcelFileDescriptor : Closeable, Parcelable
| kotlin.Any | |
| ↳ | android.os.ParcelFileDescriptor |
The FileDescriptor returned by Parcel.readFileDescriptor, allowing you to close it when done with it.
Summary
| Nested classes | |
|---|---|
| open |
An InputStream you can create on a ParcelFileDescriptor, which will take care of calling android. |
| open |
An OutputStream you can create on a ParcelFileDescriptor, which will take care of calling android. |
| open |
Exception that indicates that the file descriptor was detached. |
| abstract |
Callback indicating that a ParcelFileDescriptor has been closed. |
| Constants | |
|---|---|
| static Int |
For use with #open: append to end of file while writing. |
| static Int |
For use with #open: create the file if it doesn't already exist. |
| static Int |
For use with #open: open the file with read-only access. |
| static Int |
For use with #open: open the file with read and write access. |
| static Int |
For use with #open: erase contents of file when opening. |
| static Int |
For use with #open: if |
| static Int |
For use with #open: if |
| static Int |
For use with #open: open the file with write-only access. |
| Inherited constants | |
|---|---|
| Public constructors | |
|---|---|
ParcelFileDescriptor(wrapped: ParcelFileDescriptor!)Create a new ParcelFileDescriptor wrapped around another descriptor. |
|
| Public methods | |
|---|---|
| open static ParcelFileDescriptor! |
Take ownership of a raw native fd in to a new ParcelFileDescriptor. |
| open Boolean |
Indicates if this ParcelFileDescriptor can communicate and detect remote errors/crashes. |
| open Unit |
Detect and throw if the other end of a pipe or socket pair encountered an error or crashed. |
| open Unit |
close()Close the ParcelFileDescriptor. |
| open Unit |
closeWithError(msg: String!)Close the ParcelFileDescriptor, informing any peer that an error occurred while processing. |
| open static Array<ParcelFileDescriptor!>! |
Create two ParcelFileDescriptors structured as a data pipe. |
| open static Array<ParcelFileDescriptor!>! |
Create two ParcelFileDescriptors structured as a data pipe. |
| open static Array<ParcelFileDescriptor!>! |
Create two ParcelFileDescriptors structured as a pair of sockets connected to each other. |
| open static Array<ParcelFileDescriptor!>! |
Create two ParcelFileDescriptors structured as a pair of sockets connected to each other. |
| open Int |
Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. |
| open Int |
detachFd()Return the native fd int for this ParcelFileDescriptor and detach it from the object here. |
| open ParcelFileDescriptor! |
dup()Create a new ParcelFileDescriptor that is a dup of the existing FileDescriptor. |
| open static ParcelFileDescriptor! |
dup(orig: FileDescriptor!)Create a new ParcelFileDescriptor that is a dup of an existing FileDescriptor. |
| open static ParcelFileDescriptor! |
fromDatagramSocket(datagramSocket: DatagramSocket!)Create a new ParcelFileDescriptor from the specified DatagramSocket. |
| open static ParcelFileDescriptor! |
Create a new ParcelFileDescriptor from a raw native fd. |
| open static ParcelFileDescriptor! |
fromSocket(socket: Socket!)Create a new ParcelFileDescriptor from the specified Socket. |
| open Int |
getFd()Return the native fd int for this ParcelFileDescriptor. |
| open FileDescriptor! |
Retrieve the actual FileDescriptor associated with this object. |
| open Long |
Return the total size of the file representing this fd, as determined by |
| open static ParcelFileDescriptor! |
Create a new ParcelFileDescriptor accessing a given file. |
| open static ParcelFileDescriptor! |
open(file: File!, mode: Int, handler: Handler!, listener: ParcelFileDescriptor.OnCloseListener!)Create a new ParcelFileDescriptor accessing a given file. |
| open static Int |
Converts a string representing a file mode, such as "rw", into a bitmask suitable for use with #open. |
| open String |
toString()Returns a string representation of the object. |
| open static ParcelFileDescriptor |
wrap(pfd: ParcelFileDescriptor, handler: Handler, listener: ParcelFileDescriptor.OnCloseListener)Create a new ParcelFileDescriptor wrapping an already-opened file. |
| open Unit |
writeToParcel(out: Parcel, flags: Int)Flatten this object in to a Parcel. |
| Protected methods | |
|---|---|
| open Unit |
finalize()Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. |
| Properties | |
|---|---|
| static Parcelable.Creator<ParcelFileDescriptor!> | |
Constants
MODE_APPEND
static val MODE_APPEND: Int
For use with #open: append to end of file while writing.
Value: 33554432MODE_CREATE
static val MODE_CREATE: Int
For use with #open: create the file if it doesn't already exist.
Value: 134217728MODE_READ_ONLY
static val MODE_READ_ONLY: Int
For use with #open: open the file with read-only access.
Value: 268435456MODE_READ_WRITE
static val MODE_READ_WRITE: Int
For use with #open: open the file with read and write access.
Value: 805306368MODE_TRUNCATE
static val MODE_TRUNCATE: Int
For use with #open: erase contents of file when opening.
Value: 67108864MODE_WORLD_READABLE
static valMODE_WORLD_READABLE: Int
Deprecated: Creating world-readable files is very dangerous, and likely to cause security holes in applications. It is strongly discouraged; instead, applications should use more formal mechanism for interactions such as ContentProvider, BroadcastReceiver, and android.app.Service. There are no guarantees that this access mode will remain on a file, such as when it goes through a backup and restore.
For use with #open: if MODE_CREATE has been supplied and this file doesn't already exist, then create the file with permissions such that any application can read it.
Value: 1MODE_WORLD_WRITEABLE
static valMODE_WORLD_WRITEABLE: Int
Deprecated: Creating world-writable files is very dangerous, and likely to cause security holes in applications. It is strongly discouraged; instead, applications should use more formal mechanism for interactions such as ContentProvider, BroadcastReceiver, and android.app.Service. There are no guarantees that this access mode will remain on a file, such as when it goes through a backup and restore.
For use with #open: if MODE_CREATE has been supplied and this file doesn't already exist, then create the file with permissions such that any application can write it.
Value: 2MODE_WRITE_ONLY
static val MODE_WRITE_ONLY: Int
For use with #open: open the file with write-only access.
Value: 536870912Public constructors
ParcelFileDescriptor
ParcelFileDescriptor(wrapped: ParcelFileDescriptor!)
Create a new ParcelFileDescriptor wrapped around another descriptor. By default all method calls are delegated to the wrapped descriptor.
Public methods
adoptFd
open static fun adoptFd(fd: Int): ParcelFileDescriptor!
Take ownership of a raw native fd in to a new ParcelFileDescriptor. The returned ParcelFileDescriptor now owns the given fd, and will be responsible for closing it.
WARNING: You must not close the fd yourself after this call, and ownership of the file descriptor must have been released prior to the call to this function.
| Parameters | |
|---|---|
fd |
Int: The native fd that the ParcelFileDescriptor should adopt. |
| Return | |
|---|---|
ParcelFileDescriptor! |
Returns a new ParcelFileDescriptor holding a FileDescriptor for the given fd. |
canDetectErrors
open fun canDetectErrors(): Boolean
Indicates if this ParcelFileDescriptor can communicate and detect remote errors/crashes.
See Also
checkError
open fun checkError(): Unit
Detect and throw if the other end of a pipe or socket pair encountered an error or crashed. This allows a reader to distinguish between a valid EOF and an error/crash.
If this ParcelFileDescriptor is unable to detect remote errors, it will return silently.
| Exceptions | |
|---|---|
android.os.ParcelFileDescriptor.FileDescriptorDetachedException |
if the remote side called detachFd(). Once detached, the remote side is unable to communicate any errors through closeWithError(java.lang.String). |
java.io.IOException |
for normal errors. |
See Also
close
open fun close(): Unit
Close the ParcelFileDescriptor. This implementation closes the underlying OS resources allocated to represent this stream.
| Exceptions | |
|---|---|
java.lang.Exception |
if this resource cannot be closed |
java.io.IOException |
If an error occurs attempting to close this ParcelFileDescriptor. |
closeWithError
open fun closeWithError(msg: String!): Unit
Close the ParcelFileDescriptor, informing any peer that an error occurred while processing. If the creator of this descriptor is not observing errors, it will close normally.
| Parameters | |
|---|---|
msg |
String!: describing the error; must not be null. |
createPipe
open static fun createPipe(): Array<ParcelFileDescriptor!>!
Create two ParcelFileDescriptors structured as a data pipe. The first ParcelFileDescriptor in the returned array is the read side; the second is the write side.
createReliablePipe
open static fun createReliablePipe(): Array<ParcelFileDescriptor!>!
Create two ParcelFileDescriptors structured as a data pipe. The first ParcelFileDescriptor in the returned array is the read side; the second is the write side.
The write end has the ability to deliver an error message through closeWithError(java.lang.String) which can be handled by the read end calling checkError(), usually after detecting an EOF. This can also be used to detect remote crashes.
createReliableSocketPair
open static fun createReliableSocketPair(): Array<ParcelFileDescriptor!>!
Create two ParcelFileDescriptors structured as a pair of sockets connected to each other. The two sockets are indistinguishable.
Both ends have the ability to deliver an error message through closeWithError(java.lang.String) which can be detected by the other end calling checkError(), usually after detecting an EOF. This can also be used to detect remote crashes.
createSocketPair
open static fun createSocketPair(): Array<ParcelFileDescriptor!>!
Create two ParcelFileDescriptors structured as a pair of sockets connected to each other. The two sockets are indistinguishable.
describeContents
open fun describeContents(): Int
Describe the kinds of special objects contained in this Parcelable instance's marshaled representation. For example, if the object will include a file descriptor in the output of writeToParcel(android.os.Parcel,int), the return value of this method must include the CONTENTS_FILE_DESCRIPTOR bit.
| Return | |
|---|---|
Int |
a bitmask indicating the set of special object types marshaled by this Parcelable object instance. Value is either 0 or
|
detachFd
open fun detachFd(): Int
Return the native fd int for this ParcelFileDescriptor and detach it from the object here. You are now responsible for closing the fd in native code.
You should not detach when the original creator of the descriptor is expecting a reliable signal through #close() or closeWithError(java.lang.String).
See Also
dup
open fun dup(): ParcelFileDescriptor!
Create a new ParcelFileDescriptor that is a dup of the existing FileDescriptor. This obeys standard POSIX semantics, where the new file descriptor shared state such as file position with the original file descriptor.
dup
open static fun dup(orig: FileDescriptor!): ParcelFileDescriptor!
Create a new ParcelFileDescriptor that is a dup of an existing FileDescriptor. This obeys standard POSIX semantics, where the new file descriptor shared state such as file position with the original file descriptor.
fromDatagramSocket
open static fun fromDatagramSocket(datagramSocket: DatagramSocket!): ParcelFileDescriptor!
Create a new ParcelFileDescriptor from the specified DatagramSocket. The new ParcelFileDescriptor holds a dup of the original FileDescriptor in the DatagramSocket, so you must still close the DatagramSocket as well as the new ParcelFileDescriptor.
WARNING: Prior to API level 29, this function would not actually dup the DatagramSocket's FileDescriptor, and would take a reference to the its internal FileDescriptor instead. If the DatagramSocket gets garbage collected before the ParcelFileDescriptor, this may lead to the ParcelFileDescriptor being unexpectedly closed. To avoid this, the following pattern can be used:
<code>ParcelFileDescriptor pfd = ParcelFileDescriptor.fromDatagramSocket(socket).dup(); </code>
| Parameters | |
|---|---|
datagramSocket |
DatagramSocket!: The DatagramSocket whose FileDescriptor is used to create a new ParcelFileDescriptor. |
| Return | |
|---|---|
ParcelFileDescriptor! |
A new ParcelFileDescriptor with a duped copy of the FileDescriptor of the specified Socket. |
| Exceptions | |
|---|---|
java.io.UncheckedIOException |
if dup(java.io.FileDescriptor) throws IOException. |
fromFd
open static fun fromFd(fd: Int): ParcelFileDescriptor!
Create a new ParcelFileDescriptor from a raw native fd. The new ParcelFileDescriptor holds a dup of the original fd passed in here, so you must still close that fd as well as the new ParcelFileDescriptor.
| Parameters | |
|---|---|
fd |
Int: The native fd that the ParcelFileDescriptor should dup. |
| Return | |
|---|---|
ParcelFileDescriptor! |
Returns a new ParcelFileDescriptor holding a FileDescriptor for a dup of the given fd. |
fromSocket
open static fun fromSocket(socket: Socket!): ParcelFileDescriptor!
Create a new ParcelFileDescriptor from the specified Socket. The new ParcelFileDescriptor holds a dup of the original FileDescriptor in the Socket, so you must still close the Socket as well as the new ParcelFileDescriptor.
WARNING: Prior to API level 29, this function would not actually dup the Socket's FileDescriptor, and would take a reference to the its internal FileDescriptor instead. If the Socket gets garbage collected before the ParcelFileDescriptor, this may lead to the ParcelFileDescriptor being unexpectedly closed. To avoid this, the following pattern can be used:
<code>ParcelFileDescriptor pfd = ParcelFileDescriptor.fromSocket(socket).dup(); </code>
| Parameters | |
|---|---|
socket |
Socket!: The Socket whose FileDescriptor is used to create a new ParcelFileDescriptor. |
| Return | |
|---|---|
ParcelFileDescriptor! |
A new ParcelFileDescriptor with a duped copy of the FileDescriptor of the specified Socket. |
| Exceptions | |
|---|---|
java.io.UncheckedIOException |
if dup(java.io.FileDescriptor) throws IOException. |
getFd
open fun getFd(): Int
Return the native fd int for this ParcelFileDescriptor. The ParcelFileDescriptor still owns the fd, and it still must be closed through this API.
WARNING: Do not call close on the return value of this function or pass it to a function that assumes ownership of the fd.
getFileDescriptor
open fun getFileDescriptor(): FileDescriptor!
Retrieve the actual FileDescriptor associated with this object.
| Return | |
|---|---|
FileDescriptor! |
Returns the FileDescriptor associated with this object. |
getStatSize
open fun getStatSize(): Long
Return the total size of the file representing this fd, as determined by stat(). Returns -1 if the fd is not a file.
open
open static fun open(
file: File!,
mode: Int
): ParcelFileDescriptor!
Create a new ParcelFileDescriptor accessing a given file.
This method should only be used for files that you have direct access to; if you'd like to work with files hosted outside your app, use an API like ContentResolver.openFile(Uri, String, CancellationSignal).
| Parameters | |
|---|---|
file |
File!: The file to be opened. |
mode |
Int: The desired access mode, must be one of MODE_READ_ONLY, MODE_WRITE_ONLY, or MODE_READ_WRITE; may also be any combination of MODE_CREATE, MODE_TRUNCATE, MODE_WORLD_READABLE, and MODE_WORLD_WRITEABLE. |
| Return | |
|---|---|
ParcelFileDescriptor! |
a new ParcelFileDescriptor pointing to the given file. |
| Exceptions | |
|---|---|
java.io.FileNotFoundException |
if the given file does not exist or can not be opened with the requested mode. |
See Also
open
open static fun open(
file: File!,
mode: Int,
handler: Handler!,
listener: ParcelFileDescriptor.OnCloseListener!
): ParcelFileDescriptor!
Create a new ParcelFileDescriptor accessing a given file.
This method should only be used for files that you have direct access to; if you'd like to work with files hosted outside your app, use an API like ContentResolver.openFile(Uri, String, CancellationSignal).
| Parameters | |
|---|---|
file |
File!: The file to be opened. |
mode |
Int: The desired access mode, must be one of MODE_READ_ONLY, MODE_WRITE_ONLY, or MODE_READ_WRITE; may also be any combination of MODE_CREATE, MODE_TRUNCATE, MODE_WORLD_READABLE, and MODE_WORLD_WRITEABLE. |
handler |
Handler!: to call listener from; must not be null. |
listener |
ParcelFileDescriptor.OnCloseListener!: to be invoked when the returned descriptor has been closed; must not be null. |
| Return | |
|---|---|
ParcelFileDescriptor! |
a new ParcelFileDescriptor pointing to the given file. |
| Exceptions | |
|---|---|
java.io.FileNotFoundException |
if the given file does not exist or can not be opened with the requested mode. |
See Also
parseMode
open static fun parseMode(mode: String!): Int
Converts a string representing a file mode, such as "rw", into a bitmask suitable for use with #open.
The argument must define at least one of the following base access modes:
- "r" indicates the file should be opened in read-only mode, equivalent to
OsConstants.O_RDONLY. - "w" indicates the file should be opened in write-only mode, equivalent to
OsConstants.O_WRONLY. - "rw" indicates the file should be opened in read-write mode, equivalent to
OsConstants.O_RDWR.
- "a" indicates the file should be opened in append mode, equivalent to
OsConstants.O_APPEND. Before each write, the file offset is positioned at the end of the file. - "t" indicates the file should be opened in truncate mode, equivalent to
OsConstants.O_TRUNC. If the file already exists and is a regular file and is opened for writing, it will be truncated to length 0.
| Parameters | |
|---|---|
mode |
String!: The string representation of the file mode. Can be "r", "w", "wt", "wa", "rw" or "rwt". |
| Return | |
|---|---|
Int |
A bitmask representing the given file mode. |
| Exceptions | |
|---|---|
java.lang.IllegalArgumentException |
if the given string does not match a known file mode. |
toString
open fun toString(): String
Returns a string representation of the object.
| Return | |
|---|---|
String |
a string representation of the object. |
wrap
open static fun wrap(
pfd: ParcelFileDescriptor,
handler: Handler,
listener: ParcelFileDescriptor.OnCloseListener
): ParcelFileDescriptor
Create a new ParcelFileDescriptor wrapping an already-opened file.
| Parameters | |
|---|---|
pfd |
ParcelFileDescriptor: The already-opened file. This value cannot be null. |
handler |
Handler: to call listener from. This value cannot be null. |
listener |
ParcelFileDescriptor.OnCloseListener: to be invoked when the returned descriptor has been closed. This value cannot be null. |
| Return | |
|---|---|
ParcelFileDescriptor |
a new ParcelFileDescriptor pointing to the given file. This value cannot be null. |
writeToParcel
open fun writeToParcel(
out: Parcel,
flags: Int
): Unit
Flatten this object in to a Parcel. If Parcelable.PARCELABLE_WRITE_RETURN_VALUE is set in flags, the file descriptor will be closed after a copy is written to the Parcel.
| Parameters | |
|---|---|
dest |
The Parcel in which the object should be written. This value cannot be null. |
flags |
Int: Additional flags about how the object should be written. May be 0 or PARCELABLE_WRITE_RETURN_VALUE. Value is either 0 or a combination of the following:
|
Protected methods
finalize
protected open fun finalize(): Unit
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. A subclass overrides the finalize method to dispose of system resources or to perform other cleanup.
The general contract of finalize is that it is invoked if and when the Java virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized. The finalize method may take any action, including making this object available again to other threads; the usual purpose of finalize, however, is to perform cleanup actions before the object is irrevocably discarded. For example, the finalize method for an object that represents an input/output connection might perform explicit I/O transactions to break the connection before the object is permanently discarded.
The finalize method of class Object performs no special action; it simply returns normally. Subclasses of Object may override this definition.
The Java programming language does not guarantee which thread will invoke the finalize method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked. If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates.
After the finalize method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded.
The finalize method is never invoked more than once by a Java virtual machine for any given object.
Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored.
| Exceptions | |
|---|---|
java.lang.Throwable |
the Exception raised by this method |