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java.lang.Object

java.io.InputStream

java.io.PipedInputStream

All Implemented Interfaces:: Closeable, AutoCloseable

public class PipedInputStream extends InputStream

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.

Since:

1.0

See Also:

Field Summary

Fields

Modifier and Type

Field

Description

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.

protected static final int

PIPE_SIZE

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

Constructors

Constructor

Description

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.
Method Summary

All MethodsInstance MethodsConcrete Methods

Modifier and Type

Method

Description

int

available()

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

void

close()

Closes this 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 void

receive(int b)

Receives a byte of data.

Methods declared in class java.io.InputStream
mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, skip, skipNBytes, transferTo

Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details
- PIPE_SIZE
  protected static final int PIPE_SIZE
  
  The default size of the pipe's circular input buffer.
  Since:
  
  1.1
  
  See Also:
  Constant Field Values
- buffer
  
  protected byte[] buffer
  
  The circular buffer into which incoming data is placed.
  
  Since:
  
  1.1
- in
  
  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
  
  Since:
  
  1.1
- out
  
  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.
  
  Since:
  
  1.1
Constructor Details
- PipedInputStream
  
  public PipedInputStream(PipedOutputStream src) throws IOException
  
  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 - the stream to connect to.
  
  Throws:
  
  IOException - if an I/O error occurs.
- PipedInputStream
  
  public PipedInputStream(PipedOutputStream src, int pipeSize) throws IOException
  
  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 - the stream to connect to.
  
  pipeSize - the size of the pipe's buffer.
  
  Throws:
  
  IOException - if an I/O error occurs.
  
  IllegalArgumentException - if pipeSize <= 0.
  
  Since:
  
  1.6
- PipedInputStream
  
  public PipedInputStream()
  
  Creates a PipedInputStream so that it is not yet connected. It must be connected to a PipedOutputStream before being used.
- PipedInputStream
  
  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 - the size of the pipe's buffer.
  
  Throws:
  
  IllegalArgumentException - if pipeSize <= 0.
  
  Since:
  
  1.6
Method Details
- connect
  public void connect(PipedOutputStream src) throws IOException
  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:
  Copy [Copy snippet]
  snk.connect(src)
  or the call:
  Copy [Copy snippet]
  src.connect(snk)
  The two calls have the same effect.
  Parameters:
  
  src - The piped output stream to connect to.
  
  Throws:
  
  IOException - if an I/O error occurs.
- receive
  
  protected void receive(int b) throws IOException
  
  Receives a byte of data. This method will block if no input is available.
  
  Parameters:
  
  b - the byte being received
  
  Throws:
  
  IOException - If the pipe is broken, unconnected, closed, or if an I/O error occurs.
  
  Since:
  
  1.1
- read
  
  public int read() throws IOException
  
  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.
  
  Specified by:
  
  read in class InputStream
  
  Returns:
  
  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
  public int read(byte[] b, int off, int len) throws IOException
  
  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.
  Overrides:
  
  read in class InputStream
  
  Parameters:
  
  b - the buffer into which the data is read.
  
  off - the start offset in array b at which the data is written.
  
  len - the maximum number of bytes to read.
  
  Returns:
  
  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.
  
  See Also:
  InputStream.read()
- available
  
  public int available() throws IOException
  
  Returns the number of bytes that can be read from this input stream without blocking.
  
  Overrides:
  
  available in class InputStream
  
  Returns:
  
  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.
  
  Since:
  
  1.0.2
- close
  
  public void close() throws IOException
  
  Closes this input stream and releases any system resources associated with the stream.
  
  Specified by:
  
  close in interface AutoCloseable
  
  Specified by:
  
  close in interface Closeable
  
  Overrides:
  
  close in class InputStream
  
  Throws:
  
  IOException - if an I/O error occurs.

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Class PipedInputStream

Field Summary

Constructor Summary

Method Summary

Methods declared in class java.io.InputStream

Methods declared in class java.lang.Object

Field Details

PIPE_SIZE

buffer

in

out

Constructor Details

PipedInputStream

PipedInputStream

PipedInputStream

PipedInputStream

Method Details

connect

receive

read

read

available

close