/* * Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */package java.io;/** * Piped character-output streams. * * @author Mark Reinhold * @since JDK1.1 */public class PipedWriter extends Writer { /* REMIND: identification of the read and write sides needs to be more sophisticated. Either using thread groups (but what about pipes within a thread?) or using finalization (but it may be a long time until the next GC). */ private PipedReader sink; /* This flag records the open status of this particular writer. It * is independent of the status flags defined in PipedReader. It is * used to do a sanity check on connect. */ private boolean closed = false; /** * Creates a piped writer connected to the specified piped * reader. Data characters written to this stream will then be * available as input from <code>snk</code>. * * @param snk The piped reader to connect to. * @exception IOException if an I/O error occurs. */ public PipedWriter(PipedReader snk) throws IOException { connect(snk); } /** * Creates a piped writer that is not yet connected to a * piped reader. It must be connected to a piped reader, * either by the receiver or the sender, before being used. * * @see java.io.PipedReader#connect(java.io.PipedWriter) * @see java.io.PipedWriter#connect(java.io.PipedReader) */ public PipedWriter() { } /** * Connects this piped writer to a receiver. If this object * is already connected to some other piped reader, an * <code>IOException</code> is thrown. * <p> * If <code>snk</code> is an unconnected piped reader and * <code>src</code> is an unconnected piped writer, they may * be connected by either the call: * <blockquote><pre> * src.connect(snk)</pre></blockquote> * or the call: * <blockquote><pre> * snk.connect(src)</pre></blockquote> * The two calls have the same effect. * * @param snk the piped reader to connect to. * @exception IOException if an I/O error occurs. */ public synchronized void connect(PipedReader snk) throws IOException { if (snk == null) { throw new NullPointerException(); } else if (sink != null || snk.connected) { throw new IOException("Already connected"); } else if (snk.closedByReader || closed) { throw new IOException("Pipe closed"); } sink = snk; snk.in = -1; snk.out = 0; snk.connected = true; } /** * Writes the specified <code>char</code> to the piped output stream. * If a thread was reading data characters from the connected piped input * stream, but the thread is no longer alive, then an * <code>IOException</code> is thrown. * <p> * Implements the <code>write</code> method of <code>Writer</code>. * * @param c the <code>char</code> to be written. * @exception IOException if the pipe is * <a href=PipedOutputStream.html#BROKEN> <code>broken</code></a>, * {@link #connect(java.io.PipedReader) unconnected}, closed * or an I/O error occurs. */ public void write(int c) throws IOException { if (sink == null) { throw new IOException("Pipe not connected"); } sink.receive(c); } /** * Writes <code>len</code> characters from the specified character array * starting at offset <code>off</code> to this piped output stream. * This method blocks until all the characters are written to the output * stream. * If a thread was reading data characters from the connected piped input * stream, but the thread is no longer alive, then an * <code>IOException</code> is thrown. * * @param cbuf the data. * @param off the start offset in the data. * @param len the number of characters to write. * @exception IOException if the pipe is * <a href=PipedOutputStream.html#BROKEN> <code>broken</code></a>, * {@link #connect(java.io.PipedReader) unconnected}, closed * or an I/O error occurs. */ public void write(char cbuf[], int off, int len) throws IOException { if (sink == null) { throw new IOException("Pipe not connected"); } else if ((off | len | (off + len) | (cbuf.length - (off + len))) < 0) { throw new IndexOutOfBoundsException(); } sink.receive(cbuf, off, len); } /** * Flushes this output stream and forces any buffered output characters * to be written out. * This will notify any readers that characters are waiting in the pipe. * * @exception IOException if the pipe is closed, or an I/O error occurs. */ public synchronized void flush() throws IOException { if (sink != null) { if (sink.closedByReader || closed) { throw new IOException("Pipe closed"); } synchronized (sink) { sink.notifyAll(); } } } /** * Closes this piped output stream and releases any system resources * associated with this stream. This stream may no longer be used for * writing characters. * * @exception IOException if an I/O error occurs. */ public void close() throws IOException { closed = true; if (sink != null) { sink.receivedLast(); } }}
/*
* Copyright (c) 1996, 2006, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.io;
/**
* Piped character-output streams.
*
* @author Mark Reinhold
* @since JDK1.1
*/
public class PipedWriter extends Writer {
/* REMIND: identification of the read and write sides needs to be
more sophisticated. Either using thread groups (but what about
pipes within a thread?) or using finalization (but it may be a
long time until the next GC). */
private PipedReader sink;
/* This flag records the open status of this particular writer. It
* is independent of the status flags defined in PipedReader. It is
* used to do a sanity check on connect.
*/
private boolean closed = false;
/**
* Creates a piped writer connected to the specified piped
* reader. Data characters written to this stream will then be
* available as input from <code>snk</code>.
*
* @param snk The piped reader to connect to.
* @exception IOException if an I/O error occurs.
*/
public PipedWriter(PipedReader snk) throws IOException {
connect(snk);
}
/**
* Creates a piped writer that is not yet connected to a
* piped reader. It must be connected to a piped reader,
* either by the receiver or the sender, before being used.
*
* @see java.io.PipedReader#connect(java.io.PipedWriter)
* @see java.io.PipedWriter#connect(java.io.PipedReader)
*/
public PipedWriter() {
}
/**
* Connects this piped writer to a receiver. If this object
* is already connected to some other piped reader, an
* <code>IOException</code> is thrown.
* <p>
* If <code>snk</code> is an unconnected piped reader and
* <code>src</code> is an unconnected piped writer, they may
* be connected by either the call:
* <blockquote><pre>
* src.connect(snk)</pre></blockquote>
* or the call:
* <blockquote><pre>
* snk.connect(src)</pre></blockquote>
* The two calls have the same effect.
*
* @param snk the piped reader to connect to.
* @exception IOException if an I/O error occurs.
*/
public synchronized void connect(PipedReader snk) throws IOException {
if (snk == null) {
throw new NullPointerException();
} else if (sink != null || snk.connected) {
throw new IOException("Already connected");
} else if (snk.closedByReader || closed) {
throw new IOException("Pipe closed");
}
sink = snk;
snk.in = -1;
snk.out = 0;
snk.connected = true;
}
/**
* Writes the specified <code>char</code> to the piped output stream.
* If a thread was reading data characters from the connected piped input
* stream, but the thread is no longer alive, then an
* <code>IOException</code> is thrown.
* <p>
* Implements the <code>write</code> method of <code>Writer</code>.
*
* @param c the <code>char</code> to be written.
* @exception IOException if the pipe is
* <a href=PipedOutputStream.html#BROKEN> <code>broken</code></a>,
* {@link #connect(java.io.PipedReader) unconnected}, closed
* or an I/O error occurs.
*/
public void write(int c) throws IOException {
if (sink == null) {
throw new IOException("Pipe not connected");
}
sink.receive(c);
}
/**
* Writes <code>len</code> characters from the specified character array
* starting at offset <code>off</code> to this piped output stream.
* This method blocks until all the characters are written to the output
* stream.
* If a thread was reading data characters from the connected piped input
* stream, but the thread is no longer alive, then an
* <code>IOException</code> is thrown.
*
* @param cbuf the data.
* @param off the start offset in the data.
* @param len the number of characters to write.
* @exception IOException if the pipe is
* <a href=PipedOutputStream.html#BROKEN> <code>broken</code></a>,
* {@link #connect(java.io.PipedReader) unconnected}, closed
* or an I/O error occurs.
*/
public void write(char cbuf[], int off, int len) throws IOException {
if (sink == null) {
throw new IOException("Pipe not connected");
} else if ((off | len | (off + len) | (cbuf.length - (off + len))) < 0) {
throw new IndexOutOfBoundsException();
}
sink.receive(cbuf, off, len);
}
/**
* Flushes this output stream and forces any buffered output characters
* to be written out.
* This will notify any readers that characters are waiting in the pipe.
*
* @exception IOException if the pipe is closed, or an I/O error occurs.
*/
public synchronized void flush() throws IOException {
if (sink != null) {
if (sink.closedByReader || closed) {
throw new IOException("Pipe closed");
}
synchronized (sink) {
sink.notifyAll();
}
}
}
/**
* Closes this piped output stream and releases any system resources
* associated with this stream. This stream may no longer be used for
* writing characters.
*
* @exception IOException if an I/O error occurs.
*/
public void close() throws IOException {
closed = true;
if (sink != null) {
sink.receivedLast();
}
}
}