--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/io/PipedOutputStream.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,179 @@
+/*
+ * Copyright 1995-2006 Sun Microsystems, Inc. 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. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.io;
+
+import java.io.*;
+
+/**
+ * A piped output stream can be connected to a piped input stream
+ * to create a communications pipe. The piped output stream is the
+ * sending end of the pipe. Typically, data is written to a
+ * <code>PipedOutputStream</code> object by one thread and data is
+ * read from the connected <code>PipedInputStream</code> by some
+ * other thread. Attempting to use both objects from a single thread
+ * is not recommended as it may deadlock the thread.
+ * The pipe is said to be <a name=BROKEN> <i>broken</i> </a> if a
+ * thread that was reading data bytes from the connected piped input
+ * stream is no longer alive.
+ *
+ * @author James Gosling
+ * @see java.io.PipedInputStream
+ * @since JDK1.0
+ */
+public
+class PipedOutputStream extends OutputStream {
+
+ /* 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 PipedInputStream sink;
+
+ /**
+ * Creates a piped output stream connected to the specified piped
+ * input stream. Data bytes written to this stream will then be
+ * available as input from <code>snk</code>.
+ *
+ * @param snk The piped input stream to connect to.
+ * @exception IOException if an I/O error occurs.
+ */
+ public PipedOutputStream(PipedInputStream snk) throws IOException {
+ connect(snk);
+ }
+
+ /**
+ * Creates a piped output stream that is not yet connected to a
+ * piped input stream. It must be connected to a piped input stream,
+ * either by the receiver or the sender, before being used.
+ *
+ * @see java.io.PipedInputStream#connect(java.io.PipedOutputStream)
+ * @see java.io.PipedOutputStream#connect(java.io.PipedInputStream)
+ */
+ public PipedOutputStream() {
+ }
+
+ /**
+ * Connects this piped output stream to a receiver. If this object
+ * is already connected to some other piped input stream, an
+ * <code>IOException</code> is thrown.
+ * <p>
+ * If <code>snk</code> is an unconnected piped input stream and
+ * <code>src</code> is an unconnected piped output stream, 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 input stream to connect to.
+ * @exception IOException if an I/O error occurs.
+ */
+ public synchronized void connect(PipedInputStream snk) throws IOException {
+ if (snk == null) {
+ throw new NullPointerException();
+ } else if (sink != null || snk.connected) {
+ throw new IOException("Already connected");
+ }
+ sink = snk;
+ snk.in = -1;
+ snk.out = 0;
+ snk.connected = true;
+ }
+
+ /**
+ * Writes the specified <code>byte</code> to the piped output stream.
+ * <p>
+ * Implements the <code>write</code> method of <code>OutputStream</code>.
+ *
+ * @param b the <code>byte</code> to be written.
+ * @exception IOException if the pipe is <a href=#BROKEN> broken</a>,
+ * {@link #connect(java.io.PipedInputStream) unconnected},
+ * closed, or if an I/O error occurs.
+ */
+ public void write(int b) throws IOException {
+ if (sink == null) {
+ throw new IOException("Pipe not connected");
+ }
+ sink.receive(b);
+ }
+
+ /**
+ * Writes <code>len</code> bytes from the specified byte array
+ * starting at offset <code>off</code> to this piped output stream.
+ * This method blocks until all the bytes are written to the output
+ * stream.
+ *
+ * @param b the data.
+ * @param off the start offset in the data.
+ * @param len the number of bytes to write.
+ * @exception IOException if the pipe is <a href=#BROKEN> broken</a>,
+ * {@link #connect(java.io.PipedInputStream) unconnected},
+ * closed, or if an I/O error occurs.
+ */
+ public void write(byte b[], int off, int len) throws IOException {
+ if (sink == null) {
+ throw new IOException("Pipe not connected");
+ } else if (b == null) {
+ throw new NullPointerException();
+ } else if ((off < 0) || (off > b.length) || (len < 0) ||
+ ((off + len) > b.length) || ((off + len) < 0)) {
+ throw new IndexOutOfBoundsException();
+ } else if (len == 0) {
+ return;
+ }
+ sink.receive(b, off, len);
+ }
+
+ /**
+ * Flushes this output stream and forces any buffered output bytes
+ * to be written out.
+ * This will notify any readers that bytes are waiting in the pipe.
+ *
+ * @exception IOException if an I/O error occurs.
+ */
+ public synchronized void flush() throws IOException {
+ if (sink != null) {
+ 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 bytes.
+ *
+ * @exception IOException if an I/O error occurs.
+ */
+ public void close() throws IOException {
+ if (sink != null) {
+ sink.receivedLast();
+ }
+ }
+}