Module java.base
Package java.io

Class PipedReader

java.lang.Object
java.io.Reader
java.io.PipedReader
All Implemented Interfaces:
Closeable,AutoCloseable,Readable
public classPipedReaderextendsReader
Piped character-input streams.
Since:
1.1

  • Field Summary

    Fields declared in class java.io.Reader

    lock

  • Constructor Summary

    Constructors
    Constructor
    Description
    Creates aPipedReader so that it is not yetconnected.
    PipedReader​(int pipeSize)
    Creates aPipedReader so that it is not yetconnected and uses the specified pipe size for the pipe's buffer.
    Creates aPipedReader so that it is connected to the piped writersrc.
    PipedReader​(PipedWriter src, int pipeSize)
    Creates aPipedReader so that it is connected to the piped writersrc and uses the specified pipe size for the pipe's buffer.

  • Method Summary

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

    Methods declared in class java.io.Reader

    mark,markSupported,nullReader,read,read,reset,skip,transferTo

  • Constructor Details

    • PipedReader

      public PipedReader​(PipedWriter src) throwsIOException
      Creates aPipedReader so that it is connected to the piped writersrc. Data written tosrc 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) throwsIOException
      Creates aPipedReader so that it is connected to the piped writersrc and uses the specified pipe size for the pipe's buffer. Data written tosrc 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 - ifpipeSize <= 0.
      Since:
      1.6

    • PipedReader

      public PipedReader()
      Creates aPipedReader so that it is not yetconnected. It must beconnected to aPipedWriter before being used.

    • PipedReader

      public PipedReader​(int pipeSize)
      Creates aPipedReader so that it is not yetconnected and uses the specified pipe size for the pipe's buffer. It must beconnected to aPipedWriter before being used.
      Parameters:
      pipeSize - the size of the pipe's buffer.
      Throws:
      IllegalArgumentException - ifpipeSize <= 0.
      Since:
      1.6

  • Method Details

    • connect

      public void connect​(PipedWriter src) throwsIOException
      Causes this piped reader to be connected to the piped writersrc. If this object is already connected to some other piped writer, anIOException is thrown.

      Ifsrc is an unconnected piped writer andsnk 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() throwsIOException
      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 isbroken,unconnected, closed, or an I/O error occurs.

    • read

      public int read​(char[] cbuf, int off, int len) throwsIOException
      Reads up tolen characters of data from this piped stream into an array of characters. Less thanlen characters will be read if the end of the data stream is reached or iflen exceeds the pipe's buffer size. This method blocks until at least one character of input is available.
      Specified by:
      read in class Reader
      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 - if the pipe isbroken,unconnected, closed, or an I/O error occurs.
      IndexOutOfBoundsException - Ifoff is negative, orlen is negative, orlen is greater thancbuf.length - off

    • ready

      public boolean ready() throwsIOException
      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 isbroken,unconnected, or closed.

    • close

      public void close() throwsIOException
      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.