Added in API level 1

PipedInputStream

public class PipedInputStream
extends InputStream

java.lang.Object
↳	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.

See also:

PipedOutputStream

Summary

Constants
`int`	`PIPE_SIZE` The default size of the pipe's circular input buffer.

Fields
`protected byte[]`	`buffer` The circular buffer into which incoming data is placed.
`protected 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.
`protected 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.

Public constructors
`PipedInputStream()` Creates a `PipedInputStream` so that it is not yet connected.
`PipedInputStream(int pipeSize)` Creates a `PipedInputStream` so that it is not yet connected and uses the specified pipe size for the pipe's buffer.
`PipedInputStream(PipedOutputStream src)` Creates a `PipedInputStream` so that it is connected to the piped output stream `src`.
`PipedInputStream(PipedOutputStream src, int pipeSize)` 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
`int`	`available()` Returns the number of bytes that can be read from this input stream without blocking.
`void`	`close()` Closes this piped input stream and releases any system resources associated with the stream.
`void`	`connect(PipedOutputStream src)` Causes this piped input stream to be connected to the piped output stream `src`.
`int`	`read()` Reads the next byte of data from this piped input stream.
`int`	`read(byte[] b, int off, int len)` Reads up to `len` bytes of data from this piped input stream into an array of bytes.

Protected methods
`void`	`receive(int b)` Receives a byte of data.

Inherited methods

From class


        
          java.io.InputStream

`int`	`available()` Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected.
`void`	`close()` Closes this input stream and releases any system resources associated with the stream.
`void`	`mark(int readlimit)` Marks the current position in this input stream.
`boolean`	`markSupported()` Tests if this input stream supports the `mark` and `reset` methods.
`static InputStream`	`nullInputStream()` Returns a new `InputStream` that reads no bytes.
`int`	`read(byte[] b)` Reads some number of bytes from the input stream and stores them into the buffer array `b`.
`abstract int`	`read()` Reads the next byte of data from the input stream.
`int`	`read(byte[] b, int off, int len)` Reads up to `len` bytes of data from the input stream into an array of bytes.
`byte[]`	`readAllBytes()` Reads all remaining bytes from the input stream.
`int`	`readNBytes(byte[] b, int off, int len)` Reads the requested number of bytes from the input stream into the given byte array.
`byte[]`	`readNBytes(int len)` Reads up to a specified number of bytes from the input stream.
`void`	`reset()` Repositions this stream to the position at the time the `mark` method was last called on this input stream.
`long`	`skip(long n)` Skips over and discards `n` bytes of data from this input stream.
`void`	`skipNBytes(long n)` Skips over and discards exactly `n` bytes of data from this input stream.
`long`	`transferTo(OutputStream out)` Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          java.io.Closeable


      close()

Closes this stream and releases any system resources associated with it.

From interface


        
          java.lang.AutoCloseable


      close()

Closes this resource, relinquishing any underlying resources.

Constants

PIPE_SIZE

Added in API level 1

protected static final int PIPE_SIZE

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

Constant Value: 1024 (0x00000400)

Fields

buffer

Added in API level 1

protected byte[] buffer

The circular buffer into which incoming data is placed.

in

Added in API level 1

protected 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. in<0 implies the buffer is empty, in==out implies the buffer is full

out

Added in API level 1

protected 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.

Public constructors

PipedInputStream

Added in API level 1

public 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

public PipedInputStream (int pipeSize)

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.

Throws
`IllegalArgumentException`	if `pipeSize <= 0`.

PipedInputStream

Added in API level 1

public PipedInputStream (PipedOutputStream src)

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.

Throws
`IOException`	if an I/O error occurs.

PipedInputStream

Added in API level 9

public PipedInputStream (PipedOutputStream src, 
                int pipeSize)

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.

Throws
`IOException`	if an I/O error occurs.
`IllegalArgumentException`	if `pipeSize <= 0`.

Public methods

available

Added in API level 1

public int available ()

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

Returns
`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`.

Throws
`IOException`	if an I/O error occurs.

close

Added in API level 1

public void close ()

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

Throws
`IOException`	if an I/O error occurs.

connect

Added in API level 1

public void connect (PipedOutputStream src)

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:

snk.connect(src)

or the call:

src.connect(snk)

The two calls have the same effect.

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

Throws
`IOException`	if an I/O error occurs.

read

Added in API level 1

public int read ()

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.

Returns
`int`	the next byte of data, or `-1` if the end of the stream is reached.

Throws
`IOException`	if the pipe is `unconnected`, `broken`, closed, or if an I/O error occurs.

read

Added in API level 1

public int read (byte[] b, 
                int off, 
                int len)

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`	`byte`: 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.

Returns
`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.

Throws
`NullPointerException`	If `b` is `null`.
`IndexOutOfBoundsException`	If `off` is negative, `len` is negative, or `len` is greater than `b.length - off`
`IOException`	if the pipe is `broken`, `unconnected`, closed, or if an I/O error occurs.

Protected methods

receive

Added in API level 1

protected void receive (int b)

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

Parameters
`b`	`int`: the byte being received

Throws
`IOException`	If the pipe is `broken`, `unconnected`, closed, or if an I/O error occurs.