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.
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.
abstract Unit	write(b: Int) Writes the specified byte 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

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.

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.