src/share/classes/java/nio/file/DirectoryStream.java
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rev 7173 : [mq]: nio.diff
@@ -1,7 +1,7 @@
/*
- * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 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
@@ -26,20 +26,23 @@
package java.nio.file;
import java.util.Iterator;
import java.io.Closeable;
import java.io.IOException;
+import java.util.stream.Stream;
+import java.util.stream.Streams;
/**
* An object to iterate over the entries in a directory. A directory stream
- * allows for the convenient use of the for-each construct to iterate over a
- * directory.
+ * allows for the convenient use of the for-each construct or the {@link
+ * Stream} API to iterate over a directory.
*
* <p> <b> While {@code DirectoryStream} extends {@code Iterable}, it is not a
- * general-purpose {@code Iterable} as it supports only a single {@code
- * Iterator}; invoking the {@link #iterator iterator} method to obtain a second
- * or subsequent iterator throws {@code IllegalStateException}. </b>
+ * general-purpose {@code Iterable}. A {@code DirectoryStream} supports only a
+ * single iteration via either the {@link #iterator iterator} or the {@link
+ * #entries entries} method. Invoking either method to do a second or
+ * subsequent iteration throws {@code IllegalStateException}. </b>
*
* <p> An important property of the directory stream's {@code Iterator} is that
* its {@link Iterator#hasNext() hasNext} method is guaranteed to read-ahead by
* at least one element. If {@code hasNext} method returns {@code true}, and is
* followed by a call to the {@code next} method, it is guaranteed that the
@@ -59,31 +62,32 @@
* ...
* }
* }
* </pre>
*
- * <p> Once a directory stream is closed, then further access to the directory,
- * using the {@code Iterator}, behaves as if the end of stream has been reached.
- * Due to read-ahead, the {@code Iterator} may return one or more elements
- * after the directory stream has been closed. Once these buffered elements
- * have been read, then subsequent calls to the {@code hasNext} method returns
- * {@code false}, and subsequent calls to the {@code next} method will throw
- * {@code NoSuchElementException}.
+ * <p> Once a directory stream is closed, then further access to the
+ * directory, using the {@code Iterator} or {@code Stream}, behaves as if the
+ * end of stream has been reached. Due to read-ahead, one or more elements may
+ * be returned after the directory stream has been closed. Once these buffered
+ * elements have been read, then subsequent calls to the {@code hasNext}
+ * method returns {@code false}, and subsequent calls to the {@code next}
+ * method will throw {@code NoSuchElementException}.
*
* <p> A directory stream is not required to be <i>asynchronously closeable</i>.
* If a thread is blocked on the directory stream's iterator reading from the
* directory, and another thread invokes the {@code close} method, then the
* second thread may block until the read operation is complete.
*
* <p> If an I/O error is encountered when accessing the directory then it
- * causes the {@code Iterator}'s {@code hasNext} or {@code next} methods to
- * throw {@link DirectoryIteratorException} with the {@link IOException} as the
- * cause. As stated above, the {@code hasNext} method is guaranteed to
- * read-ahead by at least one element. This means that if {@code hasNext} method
- * returns {@code true}, and is followed by a call to the {@code next} method,
- * then it is guaranteed that the {@code next} method will not fail with a
- * {@code DirectoryIteratorException}.
+ * causes the methods to throw {@link DirectoryIteratorException} with the
+ * {@link IOException} as the cause. This could be the {@code Iterator}'s
+ * {@code hasNext} or {@code next} method or one of the {@code Stream} methods.
+ * As stated above, the {@code hasNext} method is guaranteed to read-ahead by
+ * at least one element. This means that if {@code hasNext} method returns
+ * {@code true}, and is followed by a call to the {@code next} method, then it
+ * is guaranteed that the {@code next} method will not fail with a {@code
+ * DirectoryIteratorException}.
*
* <p> The elements returned by the iterator are in no specific order. Some file
* systems maintain special links to the directory itself and the directory's
* parent directory. Entries representing these links are not returned by the
* iterator.
@@ -149,11 +153,26 @@
* Returns the iterator associated with this {@code DirectoryStream}.
*
* @return the iterator associated with this {@code DirectoryStream}
*
* @throws IllegalStateException
- * if this directory stream is closed or the iterator has already
- * been returned
+ * if this directory stream is closed or the iterator or stream
+ * has already been returned
*/
@Override
Iterator<T> iterator();
+
+ /**
+ * Returns the stream associated with this {@code DirectoryStream}.
+ *
+ * @return the stream associated with this {@code DirectoryStream}
+ *
+ * @throws IllegalStateException
+ * if this directory stream is closed or the iterator or stream
+ * has already been returned
+ * @since 1.8
+ */
+ default Stream<T> entries() {
+ return Streams.stream(Streams.spliteratorUnknownSize(iterator()),
+ Streams.STREAM_IS_DISTINCT);
+ }
}