PipedReader (Java 2 Platform SE 5.0) (original) (raw)

java.io

Class PipedReader

java.lang.Object extended by java.io.Reader java.io.PipedReader

All Implemented Interfaces:

Closeable, Readable

public class PipedReader

extends Reader

Piped character-input streams.

Since:

JDK1.1

Field Summary

Fields inherited from class java.io.Reader
lock

Constructor Summary
PipedReader() Creates a PipedReader so that it is not yet connected.
PipedReader(PipedWriter src) Creates a PipedReader so that it is connected to the piped writersrc.

Method Summary
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](../../java/io/PipedReader.html#read%28char[], int, int%29)(char[] cbuf, int off, int len) Reads up to len characters of data from this piped stream into an array of characters.
boolean	ready() Tell whether this stream is ready to be read.

Methods inherited from class java.io.Reader
mark, markSupported, read, read, reset, skip

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, [wait](../../java/lang/Object.html#wait%28long, int%29)

Constructor Detail

PipedReader

public PipedReader(PipedWriter src) throws IOException

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

Parameters:

src - the stream to connect to.

Throws:

[IOException](../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

PipedReader

public PipedReader()

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

Method Detail

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](../../java/io/IOException.html "class in java.io") - 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. If a thread was providing data characters to the connected piped writer, but the thread is no longer alive, then anIOException is thrown.

Overrides:

[read](../../java/io/Reader.html#read%28%29) in class [Reader](../../java/io/Reader.html "class in java.io")

Returns:

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

Throws:

[IOException](../../java/io/IOException.html "class in java.io") - if the pipe is broken.

read

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

Reads up to len characters of data from this piped stream into an array of characters. Less than len characters will be read if the end of the data stream is reached. This method blocks until at least one character of input is available. If a thread was providing data characters to the connected piped output, but the thread is no longer alive, then an IOException is thrown.

Specified by:

[read](../../java/io/Reader.html#read%28char[], int, int%29) in class [Reader](../../java/io/Reader.html "class in java.io")

Parameters:

cbuf - the buffer into which the data is read.

off - the start offset of the data.

len - the maximum number of characters read.

Returns:

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

Throws:

[IOException](../../java/io/IOException.html "class in java.io") - if 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](../../java/io/Reader.html#ready%28%29) in class [Reader](../../java/io/Reader.html "class in java.io")

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](../../java/io/IOException.html "class in java.io") - If an I/O error occurs

close

public void close() throws IOException

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

Specified by:

[close](../../java/io/Closeable.html#close%28%29) in interface [Closeable](../../java/io/Closeable.html "interface in java.io")

Specified by:

[close](../../java/io/Reader.html#close%28%29) in class [Reader](../../java/io/Reader.html "class in java.io")

Throws:

[IOException](../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.