diff --git a/src/share/classes/java/io/DesugarBufferedReader.java b/src/share/classes/java/io/DesugarBufferedReader.java new file mode 100644 index 00000000..b5321197 --- /dev/null +++ b/src/share/classes/java/io/DesugarBufferedReader.java @@ -0,0 +1,135 @@ +/* + * Copyright (c) 1996, 2013, 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.Iterator; +import java.util.NoSuchElementException; +import java.util.Spliterator; +import java.util.Spliterators; +import java.util.stream.Stream; +import java.util.stream.StreamSupport; + +/** + * Reads text from a character-input stream, buffering characters so as to + * provide for the efficient reading of characters, arrays, and lines. + * + *

The buffer size may be specified, or the default size may be used. The + * default is large enough for most purposes. + * + *

In general, each read request made of a Reader causes a corresponding + * read request to be made of the underlying character or byte stream. It is + * therefore advisable to wrap a BufferedReader around any Reader whose read() + * operations may be costly, such as FileReaders and InputStreamReaders. For + * example, + * + * 

+ * BufferedReader in
+ *   = new BufferedReader(new FileReader("foo.in"));
+ *
+ * + * will buffer the input from the specified file. Without buffering, each + * invocation of read() or readLine() could cause bytes to be read from the + * file, converted into characters, and then returned, which can be very + * inefficient. + * + *

Programs that use DataInputStreams for textual input can be localized by + * replacing each DataInputStream with an appropriate BufferedReader. + * + * @see FileReader + * @see InputStreamReader + * @see java.nio.file.Files#newBufferedReader + * + * @author Mark Reinhold + * @since JDK1.1 + */ +// For desugar: Recent additions to BufferedReader +public class DesugarBufferedReader { + // For desugar: static methods only + private DesugarBufferedReader() {} + + /** + * Returns a {@code Stream}, the elements of which are lines read from + * this {@code BufferedReader}. The {@link Stream} is lazily populated, + * i.e., read only occurs during the + * terminal + * stream operation. + * + *

The reader must not be operated on during the execution of the + * terminal stream operation. Otherwise, the result of the terminal stream + * operation is undefined. + * + *

After execution of the terminal stream operation there are no + * guarantees that the reader will be at a specific position from which to + * read the next character or line. + * + *

If an {@link IOException} is thrown when accessing the underlying + * {@code BufferedReader}, it is wrapped in an {@link + * UncheckedIOException} which will be thrown from the {@code Stream} + * method that caused the read to take place. This method will return a + * Stream if invoked on a BufferedReader that is closed. Any operation on + * that stream that requires reading from the BufferedReader after it is + * closed, will cause an UncheckedIOException to be thrown. + * + * @return a {@code Stream} providing the lines of text + * described by this {@code BufferedReader} + * + * @since 1.8 + */ + // For desugar: static to declare it outside receiver class + public static Stream lines(BufferedReader receiver) { + Iterator iter = new Iterator() { + String nextLine = null; + + @Override + public boolean hasNext() { + if (nextLine != null) { + return true; + } else { + try { + nextLine = receiver.readLine(); + return (nextLine != null); + } catch (IOException e) { + throw new UncheckedIOException(e); + } + } + } + + @Override + public String next() { + if (nextLine != null || hasNext()) { + String line = nextLine; + nextLine = null; + return line; + } else { + throw new NoSuchElementException(); + } + } + }; + return StreamSupport.stream(Spliterators.spliteratorUnknownSize( + iter, Spliterator.ORDERED | Spliterator.NONNULL), false); + } +} diff --git a/src/share/classes/java/io/UncheckedIOException.java b/src/share/classes/java/io/UncheckedIOException.java new file mode 100644 index 00000000..22c43e38 --- /dev/null +++ b/src/share/classes/java/io/UncheckedIOException.java @@ -0,0 +1,90 @@ +/* + * Copyright (c) 2012, 2013, 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; + +/** + * Wraps an {@link IOException} with an unchecked exception. + * + * @since 1.8 + */ +public class UncheckedIOException extends RuntimeException { + private static final long serialVersionUID = -8134305061645241065L; + + /** + * Constructs an instance of this class. + * + * @param message + * the detail message, can be null + * @param cause + * the {@code IOException} + * + * @throws NullPointerException + * if the cause is {@code null} + */ + public UncheckedIOException(String message, IOException cause) { + super(message, Objects.requireNonNull(cause)); + } + + /** + * Constructs an instance of this class. + * + * @param cause + * the {@code IOException} + * + * @throws NullPointerException + * if the cause is {@code null} + */ + public UncheckedIOException(IOException cause) { + super(Objects.requireNonNull(cause)); + } + + /** + * Returns the cause of this exception. + * + * @return the {@code IOException} which is the cause of this exception. + */ + @Override + public IOException getCause() { + return (IOException) super.getCause(); + } + + /** + * Called to read the object from a stream. + * + * @throws InvalidObjectException + * if the object is invalid or has a cause that is not + * an {@code IOException} + */ + private void readObject(ObjectInputStream s) + throws IOException, ClassNotFoundException + { + s.defaultReadObject(); + Throwable cause = super.getCause(); + if (!(cause instanceof IOException)) + throw new InvalidObjectException("Cause must be an IOException"); + } +}