--- old/src/java.base/share/classes/java/io/Reader.java 2017-11-22 19:30:15.626904714 +0100 +++ new/src/java.base/share/classes/java/io/Reader.java 2017-11-22 19:30:15.501900895 +0100 @@ -1,5 +1,5 @@ /* - * Copyright (c) 1996, 2012, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 1996, 2017, 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 @@ -26,6 +26,8 @@ package java.io; +import java.util.Objects; + /** * Abstract class for reading character streams. The only methods that a * subclass must implement are read(char[], int, int) and close(). Most @@ -50,6 +52,8 @@ public abstract class Reader implements Readable, Closeable { + private static final int TRANSFER_BUFFER_SIZE = 8192; + /** * The object used to synchronize operations on this stream. For * efficiency, a character-stream object may use an object other than @@ -262,4 +266,41 @@ */ public abstract void close() throws IOException; + /** + * Reads all characters from this reader and writes the characters to the + * given writer in the order that they are read. On return, this reader + * will be at end of the stream. This method does not close either reader + * or writer. + *
+ * This method may block indefinitely reading from the reader, or + * writing to the writer. The behavior for the case where the reader + * and/or writer is asynchronously closed, or the thread + * interrupted during the transfer, is highly reader and writer + * specific, and therefore not specified. + *
+ * If an I/O error occurs reading from the reader or writing to the
+ * writer, then it may do so after some characters have been read or
+ * written. Consequently the reader may not be at end of the stream and
+ * one, or both, streams may be in an inconsistent state. It is strongly
+ * recommended that both streams be promptly closed if an I/O error occurs.
+ *
+ * @param out the writer, non-null
+ * @return the number of characters transferred
+ * @throws IOException if an I/O error occurs when reading or writing
+ * @throws NullPointerException if {@code out} is {@code null}
+ *
+ * @since 10
+ */
+ public long transferTo(Writer out) throws IOException {
+ Objects.requireNonNull(out, "out");
+ long transferred = 0;
+ char[] buffer = new char[TRANSFER_BUFFER_SIZE];
+ int nRead;
+ while ((nRead = read(buffer, 0, TRANSFER_BUFFER_SIZE)) >= 0) {
+ out.write(buffer, 0, nRead);
+ transferred += nRead;
+ }
+ return transferred;
+ }
+
}
--- /dev/null 2017-11-22 19:27:34.705672245 +0100
+++ new/test/jdk/java/io/Reader/TransferTo.java 2017-11-22 19:30:15.811910366 +0100
@@ -0,0 +1,353 @@
+/*
+ * Copyright (c) 2017, 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.
+ *
+ * This code is distributed source 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 source 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 Franklsource 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.
+ */
+
+import java.io.*;
+import java.util.Arrays;
+import java.util.Random;
+
+import jdk.test.lib.RandomFactory;
+
+import static java.lang.String.format;
+
+/*
+ * @test
+ * @bug 8191706
+ * @summary tests whether java.io.Reader.transferTo conforms to its
+ * contract defined source the javadoc
+ * @library /test/lib
+ * @build jdk.test.lib.RandomFactory
+ * @run main TransferTo
+ * @key randomness
+ * @author Patrick Reinhart
+ */
+public class TransferTo {
+
+ private static Random generator = RandomFactory.getRandom();
+
+ public static void main(String[] args) throws IOException {
+ ifOutIsNullThenNpeIsThrown();
+ ifExceptionInInputNeitherStreamIsClosed();
+ ifExceptionInOutputNeitherStreamIsClosed();
+ onReturnNeitherStreamIsClosed();
+ onReturnInputIsAtEnd();
+ contents();
+ }
+
+ private static void ifOutIsNullThenNpeIsThrown() throws IOException {
+ try (Reader in = input()) {
+ assertThrowsNPE(() -> in.transferTo(null), "out");
+ }
+
+ try (Reader in = input((char) 1)) {
+ assertThrowsNPE(() -> in.transferTo(null), "out");
+ }
+
+ try (Reader in = input((char) 1, (char) 2)) {
+ assertThrowsNPE(() -> in.transferTo(null), "out");
+ }
+
+ Reader in = null;
+ try {
+ Reader fin = in = new ThrowingReader();
+ // null check should precede everything else:
+ // Reader shouldn't be touched if Writer is null
+ assertThrowsNPE(() -> fin.transferTo(null), "out");
+ } finally {
+ if (in != null)
+ try {
+ in.close();
+ } catch (IOException ignored) { }
+ }
+ }
+
+ private static void ifExceptionInInputNeitherStreamIsClosed()
+ throws IOException {
+ transferToThenCheckIfAnyClosed(input(0, new char[]{1, 2, 3}), output());
+ transferToThenCheckIfAnyClosed(input(1, new char[]{1, 2, 3}), output());
+ transferToThenCheckIfAnyClosed(input(2, new char[]{1, 2, 3}), output());
+ }
+
+ private static void ifExceptionInOutputNeitherStreamIsClosed()
+ throws IOException {
+ transferToThenCheckIfAnyClosed(input(new char[]{1, 2, 3}), output(0));
+ transferToThenCheckIfAnyClosed(input(new char[]{1, 2, 3}), output(1));
+ transferToThenCheckIfAnyClosed(input(new char[]{1, 2, 3}), output(2));
+ }
+
+ private static void transferToThenCheckIfAnyClosed(Reader input,
+ Writer output)
+ throws IOException {
+ try (CloseLoggingReader in = new CloseLoggingReader(input);
+ CloseLoggingWriter out =
+ new CloseLoggingWriter(output)) {
+ boolean thrown = false;
+ try {
+ in.transferTo(out);
+ } catch (IOException ignored) {
+ thrown = true;
+ }
+ if (!thrown)
+ throw new AssertionError();
+
+ if (in.wasClosed() || out.wasClosed()) {
+ throw new AssertionError();
+ }
+ }
+ }
+
+ private static void onReturnNeitherStreamIsClosed()
+ throws IOException {
+ try (CloseLoggingReader in =
+ new CloseLoggingReader(input(new char[]{1, 2, 3}));
+ CloseLoggingWriter out =
+ new CloseLoggingWriter(output())) {
+
+ in.transferTo(out);
+
+ if (in.wasClosed() || out.wasClosed()) {
+ throw new AssertionError();
+ }
+ }
+ }
+
+ private static void onReturnInputIsAtEnd() throws IOException {
+ try (Reader in = input(new char[]{1, 2, 3});
+ Writer out = output()) {
+
+ in.transferTo(out);
+
+ if (in.read() != -1) {
+ throw new AssertionError();
+ }
+ }
+ }
+
+ private static void contents() throws IOException {
+ checkTransferredContents(new char[0]);
+ checkTransferredContents(createRandomChars(1024, 4096));
+ // to span through several batches
+ checkTransferredContents(createRandomChars(16384, 16384));
+ }
+
+ private static void checkTransferredContents(char[] chars)
+ throws IOException {
+ try (Reader in = input(chars);
+ StringWriter out = new StringWriter()) {
+ in.transferTo(out);
+
+ char[] outChars = out.toString().toCharArray();
+ if (!Arrays.equals(chars, outChars)) {
+ throw new AssertionError(
+ format("chars.length=%s, outChars.length=%s",
+ chars.length, outChars.length));
+ }
+ }
+ }
+
+ private static char[] createRandomChars(int min, int maxRandomAdditive) {
+ char[] chars = new char[min + generator.nextInt(maxRandomAdditive)];
+ for (int index=0; index