Class PipedReader

java.lang.Object

java.io.Reader

java.io.PipedReader

All Implemented Interfaces:

Closeable, AutoCloseable, Readable

public class PipedReader
extends Reader

Piped character-input streams.

Since:

1.1

Field Summary

Fields declared in class Reader

lock

Modifier and Type	Field	Description
protected Object	lock	The object used to synchronize operations on this stream.

Constructor Summary

Constructors

Constructor	Description
PipedReader()	Creates a PipedReader so that it is not yet connected.
PipedReader(int pipeSize)	Creates a PipedReader so that it is not yet connected and uses the specified pipe size for the pipe's buffer.
PipedReader(PipedWriter src)	Creates a PipedReader so that it is connected to the piped writer src.
PipedReader(PipedWriter src, int pipeSize)	Creates a PipedReader so that it is connected to the piped writer src and uses the specified pipe size for the pipe's buffer.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this piped stream and releases any system resources associated with the stream.
void	connect(PipedWriter src)	Causes this piped reader to be connected to the piped writer src.
int	read()	Reads the next character of data from this piped stream.
int	read(char[] cbuf, int off, int len)	Reads characters into a portion of an array.
boolean	ready()	Tell whether this stream is ready to be read.

Methods declared in class Reader

mark, markSupported, nullReader, of, read, read, readAllAsString, readAllLines, reset, skip, transferTo

Modifier and Type	Method	Description
void	mark(int readAheadLimit)	Marks the present position in the stream.
boolean	markSupported()	Tells whether this stream supports the mark() operation.
static Reader	nullReader()	Returns a new Reader that reads no characters.
static Reader	of(CharSequence cs)	Returns a Reader that reads characters from a CharSequence.
int	read(char[] cbuf)	Reads characters into an array.
int	read(CharBuffer target)	Attempts to read characters into the specified character buffer.
String	readAllAsString()	Reads all remaining characters into a string.
List<String>	readAllLines()	Reads all remaining characters as lines of text.
void	reset()	Resets the stream.
long	skip(long n)	Skips characters.
long	transferTo(Writer out)	Reads all characters from this reader and writes the characters to the given writer in the order that they are read.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
String	toString()	Answers a string containing a concise, human-readable description of the receiver.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Constructor Details

PipedReader

public PipedReader(PipedWriter src)
            throws IOException

Creates a PipedReader so that it is connected to the piped writer src. Data 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.

PipedReader

public PipedReader(PipedWriter src,
 int pipeSize)
            throws IOException

Creates a PipedReader so that it is connected to the piped writer src and uses the specified pipe size for the pipe's buffer. Data 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

PipedReader

public PipedReader()

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

PipedReader

public PipedReader(int pipeSize)

Creates a PipedReader so that it is not yet connected and uses the specified pipe size for the pipe's buffer. It must be connected to a PipedWriter 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(PipedWriter src)
             throws IOException

Causes this piped reader to be connected to the piped writer src. If this object is already connected to some other piped writer, an IOException is thrown.

If src is an unconnected piped writer and snk is an unconnected piped reader, 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 - The piped writer to connect to.

Throws:

IOException - if an I/O error occurs.

read

public int read()
         throws IOException

Reads the next character of data from this piped stream. If no character is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Overrides:

read in class Reader

Returns:

the next character of data, or -1 if the end of the stream is reached.

Throws:

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

read

public int read(char[] cbuf,
 int off,
 int len)
         throws IOException

Reads characters into a portion of an array. This method will block until some input is available, an I/O error occurs, or the end of the stream is reached.

If len is zero, then no characters are read and 0 is returned; otherwise, there is an attempt to read at least one character. If no character is available because the stream is at its end, the value -1 is returned; otherwise, at least one character is read and stored into cbuf.

Fewer than len characters will be read if len exceeds the pipe's buffer size.

Specified by:

read in class Reader

Parameters:

cbuf - Destination buffer

off - Offset at which to start storing characters

len - Maximum number of characters to read

Returns:

The number of characters read, or -1 if the end of the stream has been reached

Throws:

IndexOutOfBoundsException - If off is negative, or len is negative, or len is greater than cbuf.length - off

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

ready

public boolean ready()
              throws IOException

Tell whether this stream is ready to be read. A piped character stream is ready if the circular buffer is not empty.

Overrides:

ready in class Reader

Returns:

True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.

Throws:

IOException - if the pipe is broken, unconnected, or closed.

close

public void close()
           throws IOException

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

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in class Reader

Throws:

IOException - if an I/O error occurs.