OutputStream
abstract class OutputStream : Closeable, Flushable
kotlin.Any | |
↳ | java.io.OutputStream |
This abstract class is the superclass of all classes representing an output stream of bytes. An output stream accepts output bytes and sends them to some sink.
Applications that need to define a subclass of OutputStream
must always provide at least a method that writes one byte of output.
Summary
Public constructors | |
---|---|
Constructor for subclasses to call. |
Public methods | |
---|---|
open Unit |
close() Closes this output stream and releases any system resources associated with this stream. |
open Unit |
flush() Flushes this output stream and forces any buffered output bytes to be written out. |
open static OutputStream! |
Returns a new |
open Unit |
Writes |
open Unit |
Writes |
abstract Unit |
Writes the specified byte to this output stream. |
Public constructors
Public methods
close
open fun close(): Unit
Closes this output stream and releases any system resources associated with this stream. The general contract of close
is that it closes the output stream. A closed stream cannot perform output operations and cannot be reopened.
The close
method of OutputStream
does nothing.
Exceptions | |
---|---|
java.lang.Exception |
if this resource cannot be closed |
java.io.IOException |
if an I/O error occurs. |
flush
open fun flush(): Unit
Flushes this output stream and forces any buffered output bytes to be written out. The general contract of flush
is that calling it is an indication that, if any bytes previously written have been buffered by the implementation of the output stream, such bytes should immediately be written to their intended destination.
If the intended destination of this stream is an abstraction provided by the underlying operating system, for example a file, then flushing the stream guarantees only that bytes previously written to the stream are passed to the operating system for writing; it does not guarantee that they are actually written to a physical device such as a disk drive.
The flush
method of OutputStream
does nothing.
Exceptions | |
---|---|
java.io.IOException |
if an I/O error occurs. |
nullOutputStream
open static fun nullOutputStream(): OutputStream!
Returns a new OutputStream
which discards all bytes. The returned stream is initially open. The stream is closed by calling the close()
method. Subsequent calls to close()
have no effect.
While the stream is open, the write(int)
, write(byte[])
, and write(byte[], int, int)
methods do nothing. After the stream has been closed, these methods all throw IOException
.
The flush()
method does nothing.
Return | |
---|---|
OutputStream! |
an OutputStream which discards all bytes |
write
open fun write(b: ByteArray!): Unit
Writes b.length
bytes from the specified byte array to this output stream. The general contract for write(b)
is that it should have exactly the same effect as the call write(b, 0, b.length)
.
Parameters | |
---|---|
b |
ByteArray!: the data. |
Exceptions | |
---|---|
java.io.IOException |
if an I/O error occurs. |
write
open fun write(
b: ByteArray!,
off: Int,
len: Int
): Unit
Writes len
bytes from the specified byte array starting at offset off
to this output stream. The general contract for write(b, off, len)
is that some of the bytes in the array b
are written to the output stream in order; element b[off]
is the first byte written and b[off+len-1]
is the last byte written by this operation.
The write
method of OutputStream
calls the write method of one argument on each of the bytes to be written out. Subclasses are encouraged to override this method and provide a more efficient implementation.
If b
is null
, a NullPointerException
is thrown.
If off
is negative, or len
is negative, or off+len
is greater than the length of the array b
, then an IndexOutOfBoundsException
is thrown.
Parameters | |
---|---|
b |
ByteArray!: the data. |
off |
Int: the start offset in the data. |
len |
Int: the number of bytes to write. |
Exceptions | |
---|---|
java.io.IOException |
if an I/O error occurs. In particular, an IOException is thrown if the output stream is closed. |
write
abstract fun write(b: Int): Unit
Writes the specified byte to this output stream. The general contract for write
is that one byte is written to the output stream. The byte to be written is the eight low-order bits of the argument b
. The 24 high-order bits of b
are ignored.
Subclasses of OutputStream
must provide an implementation for this method.
Parameters | |
---|---|
b |
Int: the byte . |
Exceptions | |
---|---|
java.io.IOException |
if an I/O error occurs. In particular, an IOException may be thrown if the output stream has been closed. |