java.io.PipedInputStream Maven / Gradle / Ivy
/*
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stub files, must be accompanied by this notice in its entirety.
This work corresponds to the API signatures of JSR 219: Foundation
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JSR 219 specification, which is available at
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*/
package java.io;
/**
* 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.
*
* @author James Gosling
* @version 1.30, 02/02/00
* @see java.io.PipedOutputStream
* @since JDK1.0
*/
public class PipedInputStream extends InputStream
{
/**
* The size of the pipe's circular input buffer.
* @since JDK1.1
*/
protected static final int PIPE_SIZE = 1024;
/**
* The circular buffer into which incoming data is placed.
* @since JDK1.1
*/
protected byte[] buffer;
/**
* 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 JDK1.1
*/
protected int in;
/**
* 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 JDK1.1
*/
protected int out;
/**
* 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.
*
* @param src the stream to connect to.
* @exception IOException if an I/O error occurs.
*/
public PipedInputStream(PipedOutputStream src) throws IOException { }
/**
* Creates a PipedInputStream so
* that it is not yet connected. It must be
* connected to a PipedOutputStream
* before being used.
*
* @see java.io.PipedInputStream#connect(java.io.PipedOutputStream)
* @see java.io.PipedOutputStream#connect(java.io.PipedInputStream)
*/
public PipedInputStream() { }
/**
* 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.
*
* @param src The piped output stream to connect to.
* @exception IOException if an I/O error occurs.
*/
public void connect(PipedOutputStream src) throws IOException { }
/**
* Receives a byte of data. This method will block if no input is
* available.
* @param b the byte being received
* @exception IOException If the pipe is broken.
* @since JDK1.1
*/
protected synchronized void receive(int b) 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. If no byte 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 bytes
* to the connected piped output stream, but
* the thread is no longer alive, then an
* IOException is thrown.
*
* @return the next byte of data, or -1 if the end of the
* stream is reached.
* @exception IOException if the pipe is broken.
*/
public synchronized int read() throws IOException {
return 0;
}
/**
* 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. This method
* blocks until at least one byte of input is available.
* If a thread was providing data bytes
* to the connected piped output stream, but
* the thread is no longer alive, then an
* IOException is thrown.
*
* @param b the buffer into which the data is read.
* @param off the start offset of the data.
* @param len the maximum number of bytes read.
* @return 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.
* @exception IOException if an I/O error occurs.
*/
public synchronized int read(byte[] b, int off, int len) throws IOException
{
return 0;
}
/**
* Returns the number of bytes that can be read from this input
* stream without blocking. This method overrides the available
* method of the parent class.
*
* @return the number of bytes that can be read from this input stream
* without blocking.
* @exception IOException if an I/O error occurs.
* @since JDK1.0.2
*/
public synchronized int available() throws IOException {
return 0;
}
/**
* Closes this piped input stream and releases any system resources
* associated with the stream.
*
* @exception IOException if an I/O error occurs.
*/
public void close() throws IOException { }
}