Added in API level 1

ByteArrayOutputStream

open class ByteArrayOutputStream : OutputStream

kotlin.Any
↳	java.io.OutputStream
	↳	java.io.ByteArrayOutputStream

This class implements an output stream in which the data is written into a byte array. The buffer automatically grows as data is written to it. The data can be retrieved using toByteArray() and toString().

Closing a ByteArrayOutputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

Summary

Public constructors
ByteArrayOutputStream() Creates a new ByteArrayOutputStream.
ByteArrayOutputStream(size: Int) Creates a new ByteArrayOutputStream, with a buffer capacity of the specified size, in bytes.

Public methods
open Unit	close() Closing a ByteArrayOutputStream has no effect.
open Unit	reset() Resets the count field of this ByteArrayOutputStream to zero, so that all currently accumulated output in the output stream is discarded.
open Int	size() Returns the current size of the buffer.
open ByteArray	toByteArray() Creates a newly allocated byte array.
open String	toString() Converts the buffer's contents into a string decoding bytes using the platform's default character set.
open String	toString(charsetName: String) Converts the buffer's contents into a string by decoding the bytes using the named charset.
open String	toString(charset: Charset) Converts the buffer's contents into a string by decoding the bytes using the specified charset.
open String	toString(hibyte: Int) Creates a newly allocated string.
open Unit	write(b: Int) Writes the specified byte to this ByteArrayOutputStream.
open Unit	write(b: ByteArray, off: Int, len: Int) Writes len bytes from the specified byte array starting at offset off to this ByteArrayOutputStream.
open Unit	writeBytes(b: ByteArray!) Writes the complete contents of the specified byte array to this ByteArrayOutputStream.
open Unit	writeTo(out: OutputStream) Writes the complete contents of this ByteArrayOutputStream to the specified output stream argument, as if by calling the output stream's write method using out.write(buf, 0, count).

Inherited functions

From class OutputStream Unit flush() 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. OutputStream! nullOutputStream() 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. Unit write(b: ByteArray!) 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).

Properties
ByteArray	buf The buffer where data is stored.
Int	count The number of valid bytes in the buffer.

Public constructors

ByteArrayOutputStream

Added in API level 1

ByteArrayOutputStream()

Creates a new ByteArrayOutputStream. The buffer capacity is initially 32 bytes, though its size increases if necessary.

ByteArrayOutputStream

Added in API level 1

ByteArrayOutputStream(size: Int)

Creates a new ByteArrayOutputStream, with a buffer capacity of the specified size, in bytes.

Parameters
size	Int: the initial size.

Exceptions
java.lang.IllegalArgumentException	if size is negative.

Public methods

close

Added in API level 1

open fun close(): Unit

Closing a ByteArrayOutputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

Exceptions
java.lang.Exception	if this resource cannot be closed
java.io.IOException	if an I/O error occurs.

reset

Added in API level 1

open fun reset(): Unit

Resets the count field of this ByteArrayOutputStream to zero, so that all currently accumulated output in the output stream is discarded. The output stream can be used again, reusing the already allocated buffer space.

See Also

• java.io.ByteArrayInputStream#count

size

Added in API level 1

open fun size(): Int

Returns the current size of the buffer.

Return
Int	the value of the count field, which is the number of valid bytes in this output stream.

See Also

• java.io.ByteArrayOutputStream#count

toByteArray

Added in API level 1

open fun toByteArray(): ByteArray

Creates a newly allocated byte array. Its size is the current size of this output stream and the valid contents of the buffer have been copied into it.

Return
ByteArray	the current contents of this output stream, as a byte array.

See Also

• java.io.ByteArrayOutputStream#size()

toString

Added in API level 1

open fun toString(): String

Converts the buffer's contents into a string decoding bytes using the platform's default character set. The length of the new String is a function of the character set, and hence may not be equal to the size of the buffer.

This method always replaces malformed-input and unmappable-character sequences with the default replacement string for the platform's default character set. The java.nio.charset.CharsetDecoder class should be used when more control over the decoding process is required.

Return
String	String decoded from the buffer's contents.

toString

Added in API level 1

open fun toString(charsetName: String): String

Converts the buffer's contents into a string by decoding the bytes using the named charset.

This method is equivalent to toString(charset) that takes a charset.

An invocation of this method of the form

<code>ByteArrayOutputStream b = ...
       b.toString("UTF-8")
       </code>

behaves in exactly the same way as the expression

<code>ByteArrayOutputStream b = ...
       b.toString(StandardCharsets.UTF_8)
       </code>

Parameters
charsetName	String: the name of a supported charset

Return
String	String decoded from the buffer's contents.

Exceptions
java.io.UnsupportedEncodingException	If the named charset is not supported

toString

Added in API level 33

open fun toString(charset: Charset): String

Converts the buffer's contents into a string by decoding the bytes using the specified charset. The length of the new String is a function of the charset, and hence may not be equal to the length of the byte array.

This method always replaces malformed-input and unmappable-character sequences with the charset's default replacement string. The class should be used when more control over the decoding process is required.

Parameters
charset	Charset: the charset to be used to decode the bytes

Return
String	String decoded from the buffer's contents.

toString

Added in API level 1
Deprecated in API level 15

open fun toString(hibyte: Int): String

Deprecated: This method does not properly convert bytes into characters. As of JDK 1.1, the preferred way to do this is via the toString(java.lang.String) or toString(java.nio.charset.Charset) method, which takes an encoding-name or charset argument, or the toString() method, which uses the platform's default character encoding.

Creates a newly allocated string. Its size is the current size of the output stream and the valid contents of the buffer have been copied into it. Each character c in the resulting string is constructed from the corresponding element b in the byte array such that:

<code>c == (char)(((hibyte &amp; 0xff) &lt;&lt; 8) | (b &amp; 0xff))
  </code>

Parameters
hibyte	Int: the high byte of each resulting Unicode character.

Return
String	the current contents of the output stream, as a string.

See Also

• java.io.ByteArrayOutputStream#size()
• java.io.ByteArrayOutputStream#toString(String)
• java.io.ByteArrayOutputStream#toString()

write

Added in API level 1

open fun write(b: Int): Unit

Writes the specified byte to this ByteArrayOutputStream.

Parameters
b	Int: the byte to be written.

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, 
    off: Int, 
    len: Int
): Unit

Writes len bytes from the specified byte array starting at offset off to this ByteArrayOutputStream.

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.
java.lang.NullPointerException	if b is null.
java.lang.IndexOutOfBoundsException	if off is negative, len is negative, or len is greater than b.length - off

writeBytes

Added in API level 33

open fun writeBytes(b: ByteArray!): Unit

Writes the complete contents of the specified byte array to this ByteArrayOutputStream.

Parameters
b	ByteArray!: the data.

Exceptions
java.lang.NullPointerException	if b is null.

writeTo

Added in API level 1

open fun writeTo(out: OutputStream): Unit

Writes the complete contents of this ByteArrayOutputStream to the specified output stream argument, as if by calling the output stream's write method using out.write(buf, 0, count).

Parameters
out	OutputStream: the output stream to which to write the data.

Exceptions
java.lang.NullPointerException	if out is null.
java.io.IOException	if an I/O error occurs.

Properties

buf

Added in API level 1

protected var buf: ByteArray

The buffer where data is stored.

count

Added in API level 1

protected var count: Int

The number of valid bytes in the buffer.