--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/io/Reader.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,265 @@
+/*
+ * Copyright (c) 1996, 2012, 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;
+
+
+/**
+ * Abstract class for reading character streams. The only methods that a
+ * subclass must implement are read(char[], int, int) and close(). Most
+ * subclasses, however, will override some of the methods defined here in order
+ * to provide higher efficiency, additional functionality, or both.
+ *
+ *
+ * @see BufferedReader
+ * @see LineNumberReader
+ * @see CharArrayReader
+ * @see InputStreamReader
+ * @see FileReader
+ * @see FilterReader
+ * @see PushbackReader
+ * @see PipedReader
+ * @see StringReader
+ * @see Writer
+ *
+ * @author Mark Reinhold
+ * @since 1.1
+ */
+
+public abstract class Reader implements Readable, Closeable {
+
+ /**
+ * The object used to synchronize operations on this stream. For
+ * efficiency, a character-stream object may use an object other than
+ * itself to protect critical sections. A subclass should therefore use
+ * the object in this field rather than {@code this} or a synchronized
+ * method.
+ */
+ protected Object lock;
+
+ /**
+ * Creates a new character-stream reader whose critical sections will
+ * synchronize on the reader itself.
+ */
+ protected Reader() {
+ this.lock = this;
+ }
+
+ /**
+ * Creates a new character-stream reader whose critical sections will
+ * synchronize on the given object.
+ *
+ * @param lock The Object to synchronize on.
+ */
+ protected Reader(Object lock) {
+ if (lock == null) {
+ throw new NullPointerException();
+ }
+ this.lock = lock;
+ }
+
+ /**
+ * Attempts to read characters into the specified character buffer.
+ * The buffer is used as a repository of characters as-is: the only
+ * changes made are the results of a put operation. No flipping or
+ * rewinding of the buffer is performed.
+ *
+ * @param target the buffer to read characters into
+ * @return The number of characters added to the buffer, or
+ * -1 if this source of characters is at its end
+ * @throws IOException if an I/O error occurs
+ * @throws NullPointerException if target is null
+ * @throws java.nio.ReadOnlyBufferException if target is a read only buffer
+ * @since 1.5
+ */
+ public int read(java.nio.CharBuffer target) throws IOException {
+ int len = target.remaining();
+ char[] cbuf = new char[len];
+ int n = read(cbuf, 0, len);
+ if (n > 0)
+ target.put(cbuf, 0, n);
+ return n;
+ }
+
+ /**
+ * Reads a single character. This method will block until a character is
+ * available, an I/O error occurs, or the end of the stream is reached.
+ *
+ * <p> Subclasses that intend to support efficient single-character input
+ * should override this method.
+ *
+ * @return The character read, as an integer in the range 0 to 65535
+ * ({@code 0x00-0xffff}), or -1 if the end of the stream has
+ * been reached
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public int read() throws IOException {
+ char cb[] = new char[1];
+ if (read(cb, 0, 1) == -1)
+ return -1;
+ else
+ return cb[0];
+ }
+
+ /**
+ * Reads characters into an array. This method will block until some input
+ * is available, an I/O error occurs, or the end of the stream is reached.
+ *
+ * @param cbuf Destination buffer
+ *
+ * @return The number of characters read, or -1
+ * if the end of the stream
+ * has been reached
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public int read(char cbuf[]) throws IOException {
+ return read(cbuf, 0, cbuf.length);
+ }
+
+ /**
+ * Reads characters into a portion of an array. This method will block
+ * until some input is available, an I/O error occurs, or the end of the
+ * stream is reached.
+ *
+ * @param cbuf Destination buffer
+ * @param off Offset at which to start storing characters
+ * @param len Maximum number of characters to read
+ *
+ * @return The number of characters read, or -1 if the end of the
+ * stream has been reached
+ *
+ * @exception IOException If an I/O error occurs
+ * @exception IndexOutOfBoundsException
+ * If {@code off} is negative, or {@code len} is negative,
+ * or {@code len} is greater than {@code cbuf.length - off}
+ */
+ public abstract int read(char cbuf[], int off, int len) throws IOException;
+
+ /** Maximum skip-buffer size */
+ private static final int maxSkipBufferSize = 8192;
+
+ /** Skip buffer, null until allocated */
+ private char skipBuffer[] = null;
+
+ /**
+ * Skips characters. This method will block until some characters are
+ * available, an I/O error occurs, or the end of the stream is reached.
+ *
+ * @param n The number of characters to skip
+ *
+ * @return The number of characters actually skipped
+ *
+ * @exception IllegalArgumentException If <code>n</code> is negative.
+ * @exception IOException If an I/O error occurs
+ */
+ public long skip(long n) throws IOException {
+ if (n < 0L)
+ throw new IllegalArgumentException("skip value is negative");
+ int nn = (int) Math.min(n, maxSkipBufferSize);
+ synchronized (lock) {
+ if ((skipBuffer == null) || (skipBuffer.length < nn))
+ skipBuffer = new char[nn];
+ long r = n;
+ while (r > 0) {
+ int nc = read(skipBuffer, 0, (int)Math.min(r, nn));
+ if (nc == -1)
+ break;
+ r -= nc;
+ }
+ return n - r;
+ }
+ }
+
+ /**
+ * Tells whether this stream is ready to be read.
+ *
+ * @return 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.
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public boolean ready() throws IOException {
+ return false;
+ }
+
+ /**
+ * Tells whether this stream supports the mark() operation. The default
+ * implementation always returns false. Subclasses should override this
+ * method.
+ *
+ * @return true if and only if this stream supports the mark operation.
+ */
+ public boolean markSupported() {
+ return false;
+ }
+
+ /**
+ * Marks the present position in the stream. Subsequent calls to reset()
+ * will attempt to reposition the stream to this point. Not all
+ * character-input streams support the mark() operation.
+ *
+ * @param readAheadLimit Limit on the number of characters that may be
+ * read while still preserving the mark. After
+ * reading this many characters, attempting to
+ * reset the stream may fail.
+ *
+ * @exception IOException If the stream does not support mark(),
+ * or if some other I/O error occurs
+ */
+ public void mark(int readAheadLimit) throws IOException {
+ throw new IOException("mark() not supported");
+ }
+
+ /**
+ * Resets the stream. If the stream has been marked, then attempt to
+ * reposition it at the mark. If the stream has not been marked, then
+ * attempt to reset it in some way appropriate to the particular stream,
+ * for example by repositioning it to its starting point. Not all
+ * character-input streams support the reset() operation, and some support
+ * reset() without supporting mark().
+ *
+ * @exception IOException If the stream has not been marked,
+ * or if the mark has been invalidated,
+ * or if the stream does not support reset(),
+ * or if some other I/O error occurs
+ */
+ public void reset() throws IOException {
+ throw new IOException("reset() not supported");
+ }
+
+ /**
+ * Closes the stream and releases any system resources associated with
+ * it. Once the stream has been closed, further read(), ready(),
+ * mark(), reset(), or skip() invocations will throw an IOException.
+ * Closing a previously closed stream has no effect.
+ *
+ * @exception IOException If an I/O error occurs
+ */
+ public abstract void close() throws IOException;
+
+}