Added in API level 1

PipedInputStream

open class PipedInputStream : InputStream

kotlin.Any
↳	java.io.InputStream
	↳	java.io.PipedInputStream

A piped input stream should be connected to a piped output stream; the piped input stream then provides whatever data bytes are written to the piped output stream. Typically, data is read from a PipedInputStream object by one thread and data is written to the corresponding PipedOutputStream by some other thread. Attempting to use both objects from a single thread is not recommended, as it may deadlock the thread. The piped input stream contains a buffer, decoupling read operations from write operations, within limits. A pipe is said to be broken if a thread that was providing data bytes to the connected piped output stream is no longer alive.

Summary

Constants
static Int	PIPE_SIZE The default size of the pipe's circular input buffer.

Public constructors
PipedInputStream() Creates a PipedInputStream so that it is not yet connected.
PipedInputStream(pipeSize: Int) Creates a PipedInputStream so that it is not yet connected and uses the specified pipe size for the pipe's buffer.
PipedInputStream(src: PipedOutputStream!) Creates a PipedInputStream so that it is connected to the piped output stream src.
PipedInputStream(src: PipedOutputStream!, pipeSize: Int) Creates a PipedInputStream so that it is connected to the piped output stream src and uses the specified pipe size for the pipe's buffer.

Public methods
open Int	available() Returns the number of bytes that can be read from this input stream without blocking.
open Unit	close() Closes this piped input stream and releases any system resources associated with the stream.
open Unit	connect(src: PipedOutputStream!) Causes this piped input stream to be connected to the piped output stream src.
open Int	read() Reads the next byte of data from this piped input stream.
open Int	read(b: ByteArray!, off: Int, len: Int) Reads up to len bytes of data from this piped input stream into an array of bytes.

Protected methods
open Unit	receive(b: Int) Receives a byte of data.

Inherited functions

From class InputStream Unit mark(readlimit: Int) Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes. The readlimit arguments tells this input stream to allow that many bytes to be read before the mark position gets invalidated. The general contract of mark is that, if the method markSupported returns true, the stream somehow remembers all the bytes read after the call to mark and stands ready to supply those same bytes again if and whenever the method reset is called. However, the stream is not required to remember any data at all if more than readlimit bytes are read from the stream before reset is called. Marking a closed stream should not have any effect on the stream. The mark method of InputStream does nothing. Boolean markSupported() Tests if this input stream supports the mark and reset methods. Whether or not mark and reset are supported is an invariant property of a particular input stream instance. The markSupported method of InputStream returns false. InputStream! nullInputStream() Returns a new InputStream that reads no 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 available(), read(), read(byte[]), read(byte[], int, int), readAllBytes(), readNBytes(byte[], int, int), readNBytes(int), skip(long), skipNBytes(long), and transferTo() methods all behave as if end of stream has been reached. After the stream has been closed, these methods all throw IOException. The markSupported() method returns false. The mark() method does nothing, and the reset() method throws IOException. Int read(b: ByteArray!) Reads some number of bytes from the input stream and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown. If the length of b is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at the end of the file, the value -1 is returned; otherwise, at least one byte is read and stored into b. The first byte read is stored into element b[0], the next one into b[1], and so on. The number of bytes read is, at most, equal to the length of b. Let k be the number of bytes actually read; these bytes will be stored in elements b[0] through b[k-1], leaving elements b[k] through b[b.length-1] unaffected. The read(b) method for class InputStream has the same effect as: <code>read(b, 0, b.length) </code> ByteArray! readAllBytes() Reads all remaining bytes from the input stream. This method blocks until all remaining bytes have been read and end of stream is detected, or an exception is thrown. This method does not close the input stream. When this stream reaches end of stream, further invocations of this method will return an empty byte array. Note that this method is intended for simple cases where it is convenient to read all bytes into a byte array. It is not intended for reading input streams with large amounts of data. The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified. If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs. Int readNBytes(b: ByteArray!, off: Int, len: Int) Reads the requested number of bytes from the input stream into the given byte array. This method blocks until len bytes of input data have been read, end of stream is detected, or an exception is thrown. The number of bytes actually read, possibly zero, is returned. This method does not close the input stream. In the case where end of stream is reached before len bytes have been read, then the actual number of bytes read will be returned. When this stream reaches end of stream, further invocations of this method will return zero. If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read up to len bytes. The first byte read is stored into element b[off], the next one in to b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k ] through b[off+len-1] unaffected. The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified. If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes of b have been updated with data from the input stream. Consequently the input stream and b may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs. ByteArray! readNBytes(len: Int) Reads up to a specified number of bytes from the input stream. This method blocks until the requested number of bytes has been read, end of stream is detected, or an exception is thrown. This method does not close the input stream. The length of the returned array equals the number of bytes read from the stream. If len is zero, then no bytes are read and an empty byte array is returned. Otherwise, up to len bytes are read from the stream. Fewer than len bytes may be read if end of stream is encountered. When this stream reaches end of stream, further invocations of this method will return an empty byte array. Note that this method is intended for simple cases where it is convenient to read the specified number of bytes into a byte array. The total amount of memory allocated by this method is proportional to the number of bytes read from the stream which is bounded by len. Therefore, the method may be safely called with very large values of len provided sufficient memory is available. The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified. If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs. Unit reset() Repositions this stream to the position at the time the mark method was last called on this input stream. The general contract of reset is: If the method markSupported returns true, then: If the method mark has not been called since the stream was created, or the number of bytes read from the stream since mark was last called is larger than the argument to mark at that last call, then an IOException might be thrown. If such an IOException is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call to mark (or since the start of the file, if mark has not been called) will be resupplied to subsequent callers of the read method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset. If the method markSupported returns false, then: The call to reset may throw an IOException. If an IOException is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of the read method depend on the particular type of the input stream. The method reset for class InputStream does nothing except throw an IOException. Long skip(n: Long) Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If n is negative, the skip method for class InputStream always returns 0, and no bytes are skipped. Subclasses may handle the negative value differently. The skip method implementation of this class creates a byte array and then repeatedly reads into it until n bytes have been read or the end of the stream has been reached. Subclasses are encouraged to provide a more efficient implementation of this method. For instance, the implementation may depend on the ability to seek. Unit skipNBytes(n: Long) Skips over and discards exactly n bytes of data from this input stream. If n is zero, then no bytes are skipped. If n is negative, then no bytes are skipped. Subclasses may handle the negative value differently. This method blocks until the requested number of bytes has been skipped, end of file is reached, or an exception is thrown. If end of stream is reached before the stream is at the desired position, then an EOFException is thrown. If an I/O error occurs, then the input stream may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs. Long transferTo(out: OutputStream!) Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read. On return, this input stream will be at end of stream. This method does not close either stream. This method may block indefinitely reading from the input stream, or writing to the output stream. The behavior for the case where the input and/or output stream is asynchronously closed, or the thread interrupted during the transfer, is highly input and output stream specific, and therefore not specified. If an I/O error occurs reading from the input stream or writing to the output stream, then it may do so after some bytes have been read or written. Consequently the input stream may not be at end of stream and one, or both, streams may be in an inconsistent state. It is strongly recommended that both streams be promptly closed if an I/O error occurs.

Properties
ByteArray!	buffer The circular buffer into which incoming data is placed.
Int	in The index of the position in the circular buffer at which the next byte of data will be stored when received from the connected piped output stream.
Int	out The index of the position in the circular buffer at which the next byte of data will be read by this piped input stream.

Constants

PIPE_SIZE

Added in API level 1

protected static val PIPE_SIZE: Int

The default size of the pipe's circular input buffer.

Value: 1024

Public constructors

PipedInputStream

Added in API level 1

PipedInputStream()

Creates a PipedInputStream so that it is not yet connected. It must be connected to a PipedOutputStream before being used.

PipedInputStream

Added in API level 9

PipedInputStream(pipeSize: Int)

Creates a PipedInputStream so that it is not yet connected and uses the specified pipe size for the pipe's buffer. It must be connected to a PipedOutputStream before being used.

Parameters
pipeSize	Int: the size of the pipe's buffer.

Exceptions
java.lang.IllegalArgumentException	if pipeSize <= 0.

PipedInputStream

Added in API level 1

PipedInputStream(src: PipedOutputStream!)

Creates a PipedInputStream so that it is connected to the piped output stream src. Data bytes written to src will then be available as input from this stream.

Parameters
src	PipedOutputStream!: the stream to connect to.

Exceptions
java.io.IOException	if an I/O error occurs.

PipedInputStream

Added in API level 9

PipedInputStream(
    src: PipedOutputStream!, 
    pipeSize: Int)

Creates a PipedInputStream so that it is connected to the piped output stream src and uses the specified pipe size for the pipe's buffer. Data bytes written to src will then be available as input from this stream.

Parameters
src	PipedOutputStream!: the stream to connect to.
pipeSize	Int: the size of the pipe's buffer.

Exceptions
java.io.IOException	if an I/O error occurs.
java.lang.IllegalArgumentException	if pipeSize <= 0.

Public methods

available

Added in API level 1

open fun available(): Int

Returns the number of bytes that can be read from this input stream without blocking.

Return
Int	the number of bytes that can be read from this input stream without blocking, or 0 if this input stream has been closed by invoking its #close() method, or if the pipe is unconnected, or broken.

Exceptions
java.io.IOException	if an I/O error occurs.
java.io.IOException	if an I/O error occurs.

close

Added in API level 1

open fun close(): Unit

Closes this piped input stream and releases any system resources associated with the stream.

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

connect

Added in API level 1

open fun connect(src: PipedOutputStream!): Unit

Causes this piped input stream to be connected to the piped output stream src. If this object is already connected to some other piped output stream, an IOException is thrown.

If src is an unconnected piped output stream and snk is an unconnected piped input stream, they may be connected by either the call:

<code>snk.connect(src)</code>

or the call:

<code>src.connect(snk)</code>

The two calls have the same effect.

Parameters
src	PipedOutputStream!: The piped output stream to connect to.

Exceptions
java.io.IOException	if an I/O error occurs.

read

Added in API level 1

open fun read(): Int

Reads the next byte of data from this piped input stream. The value byte is returned as an int in the range 0 to 255. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Return
Int	the next byte of data, or -1 if the end of the stream is reached.

Exceptions
java.io.IOException	if an I/O error occurs.
java.io.IOException	if the pipe is unconnected, broken, closed, or if an I/O error occurs.

read

Added in API level 1

open fun read(
    b: ByteArray!, 
    off: Int, 
    len: Int
): Int

Reads up to len bytes of data from this piped input stream into an array of bytes. Less than len bytes will be read if the end of the data stream is reached or if len exceeds the pipe's buffer size. If len is zero, then no bytes are read and 0 is returned; otherwise, the method blocks until at least 1 byte of input is available, end of the stream has been detected, or an exception is thrown.

Parameters
b	ByteArray!: the buffer into which the data is read.
off	Int: the start offset in the destination array b
len	Int: the maximum number of bytes read.

Return
Int	the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Exceptions
java.io.IOException	If the first byte cannot be read for any reason other than end of file, or if the input stream has been closed, or if some other I/O error occurs.
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
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
java.io.IOException	if the pipe is broken, unconnected, closed, or if an I/O error occurs.

Protected methods

receive

Added in API level 1

protected open fun receive(b: Int): Unit

Receives a byte of data. This method will block if no input is available.

Parameters
b	Int: the byte being received

Exceptions
java.io.IOException	If the pipe is broken, unconnected, closed, or if an I/O error occurs.

Properties

buffer

Added in API level 1

protected var buffer: ByteArray!

The circular buffer into which incoming data is placed.

in

Added in API level 1

protected var in: Int

The index of the position in the circular buffer at which the next byte of data will be stored when received from the connected piped output stream. in<0 implies the buffer is empty, in==out implies the buffer is full

out

Added in API level 1

protected var out: Int

The index of the position in the circular buffer at which the next byte of data will be read by this piped input stream.