| /* | |
| * Copyright (c) 1996, 2024, 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; | |
| import java.util.Objects; | |
| /** | |
| * Piped character-output streams. | |
| * | |
| * @author Mark Reinhold | |
| * @since 1.1 | |
| */ | |
| 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}. | |
| * | |
| * @param snk The piped reader to connect to. | |
| * @throws IOException if an I/O error occurs. | |
| */ | |
| @SuppressWarnings("this-escape") | |
| 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} is thrown. | |
| * <p> | |
| * If {@code snk} is an unconnected piped reader and | |
| * {@code src} is an unconnected piped writer, they may | |
| * be connected by either the call: | |
| * {@snippet lang=java : | |
| * src.connect(snk) | |
| * } | |
| * or the call: | |
| * {@snippet lang=java : | |
| * snk.connect(src) | |
| * } | |
| * The two calls have the same effect. | |
| * | |
| * @param snk the piped reader to connect to. | |
| * @throws 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} 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} is thrown. | |
| * <p> | |
| * Implements the {@code write} method of {@code Writer}. | |
| * | |
| * @param c the {@code char} to be written. | |
| * @throws IOException if the pipe is | |
| * <a href=PipedOutputStream.html#BROKEN> {@code broken}</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} characters from the specified character array | |
| * starting at offset {@code off} 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} is thrown. | |
| * | |
| * @param cbuf the data. | |
| * @param off the start offset in the data. | |
| * @param len the number of characters to write. | |
| * | |
| * @throws IndexOutOfBoundsException | |
| * If {@code off} is negative, or {@code len} is negative, | |
| * or {@code off + len} is negative or greater than the length | |
| * of the given array | |
| * | |
| * @throws IOException if the pipe is | |
| * <a href=PipedOutputStream.html#BROKEN>{@code broken}</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"); | |
| } | |
| Objects.checkFromIndexSize(off, len, cbuf.length); | |
| 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. | |
| * | |
| * @throws 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. | |
| * | |
| * @throws IOException if an I/O error occurs. | |
| */ | |
| public void close() throws IOException { | |
| closed = true; | |
| if (sink != null) { | |
| sink.receivedLast(); | |
| } | |
| } | |
| } |