Added in API level 1

OutputStream

abstract class OutputStream : Closeable, Flushable

kotlin.Any
↳	java.io.OutputStream

Known Direct Subclasses

ByteArrayOutputStream, FileOutputStream, FilterOutputStream, ObjectOutputStream, PipedOutputStream

ByteArrayOutputStream	This class implements an output stream in which the data is written into a byte array.
FileOutputStream	A file output stream is an output stream for writing data to a `File` or to a `FileDescriptor`.
FilterOutputStream	This class is the superclass of all classes that filter output streams.
ObjectOutputStream	An ObjectOutputStream writes primitive data types and graphs of Java objects to an OutputStream.
PipedOutputStream	A piped output stream can be connected to a piped input stream to create a communications pipe.

Known Indirect Subclasses

AssetFileDescriptor.AutoCloseOutputStream, Base64OutputStream, BufferedOutputStream, CheckedOutputStream, CipherOutputStream, DataOutputStream, DeflaterOutputStream, DigestOutputStream, GZIPOutputStream, InflaterOutputStream, JarOutputStream, ParcelFileDescriptor.AutoCloseOutputStream, and 2 others.

AssetFileDescriptor.AutoCloseOutputStream	An OutputStream you can create on a ParcelFileDescriptor, which will take care of calling android.
Base64OutputStream	An OutputStream that does Base64 encoding on the data written to it, writing the resulting data to another OutputStream.
BufferedOutputStream	The class implements a buffered output stream.
CheckedOutputStream	An output stream that also maintains a checksum of the data being written.
CipherOutputStream	A CipherOutputStream is composed of an OutputStream and a Cipher so that write() methods first process the data before writing them out to the underlying OutputStream.
DataOutputStream	A data output stream lets an application write primitive Java data types to an output stream in a portable way.
DeflaterOutputStream	This class implements an output stream filter for compressing data in the "deflate" compression format.
DigestOutputStream	A transparent stream that updates the associated message digest using the bits going through the stream.
GZIPOutputStream	This class implements a stream filter for writing compressed data in the GZIP file format.
InflaterOutputStream	Implements an output stream filter for uncompressing data stored in the "deflate" compression format.
JarOutputStream	The `JarOutputStream` class is used to write the contents of a JAR file to any output stream.
ParcelFileDescriptor.AutoCloseOutputStream	An OutputStream you can create on a ParcelFileDescriptor, which will take care of calling android.
PrintStream	A `PrintStream` adds functionality to another output stream, namely the ability to print representations of various data values conveniently.
ZipOutputStream	This class implements an output stream filter for writing files in the ZIP file format.

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
`OutputStream()` 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!	`nullOutputStream()` Returns a new `OutputStream` which discards all bytes.
abstract Unit	`write(b: Int)` Writes the specified byte to this output stream.
open Unit	`write(b: ByteArray!)` Writes `b.length` bytes from the specified byte array to this output stream.
open Unit	`write(b: ByteArray!, off: Int, len: Int)` Writes `len` bytes from the specified byte array starting at offset `off` to this output stream.

Public constructors

OutputStream

Added in API level 1

OutputStream()

Constructor for subclasses to call.

Public methods

close

Added in API level 1

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

Added in API level 1

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

Added in API level 33

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

Added in API level 1

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.

write

Added in API level 1

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.

See Also

java.io.OutputStream#write(byte[], int, int)

write

Added in API level 1

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.