RFR 8164934: Optional.map() javadoc code example is incorrect

[Chris Hegarty]

On 8 Nov 2016, at 23:52, Paul Sandoz <paul.sandoz at oracle.com> wrote:
> 
> Hi,
> 
> Please review an update to the api note of Optional.map() which embarrassingly contained erroneous code (labouring under the misapprehension that exception transparency is supported!).
> 
> I tweaked the example to refer to a Stream<URI> where a URI is transformed into a Path.
> 

This looks fine Paul.

-Chris.

> Paul.
> 
> diff -r df7e627c7224 src/java.base/share/classes/java/util/Optional.java
> --- a/src/java.base/share/classes/java/util/Optional.java	Tue Nov 08 15:28:44 2016 -0800
> +++ b/src/java.base/share/classes/java/util/Optional.java	Tue Nov 08 15:37:23 2016 -0800
> @@ -214,20 +214,20 @@
>      * @apiNote
>      * This method supports post-processing on {@code Optional} values, without
>      * the need to explicitly check for a return status.  For example, the
> -     * following code traverses a stream of file names, selects one that has not
> -     * yet been processed, and then opens that file, returning an
> -     * {@code Optional<FileInputStream>}:
> +     * following code traverses a stream of URIs, selects one that has not
> +     * yet been processed, and creates a path from that URI, returning
> +     * an {@code Optional<Path>}:
>      *
>      * <pre>{@code
> -     *     Optional<FileInputStream> fis =
> -     *         names.stream().filter(name -> !isProcessedYet(name))
> +     *     Optional<Path> p =
> +     *         uris.stream().filter(uri -> !isProcessedYet(uri))
>      *                       .findFirst()
> -     *                       .map(name -> new FileInputStream(name));
> +     *                       .map(Paths::get);
>      * }</pre>
>      *
> -     * Here, {@code findFirst} returns an {@code Optional<String>}, and then
> -     * {@code map} returns an {@code Optional<FileInputStream>} for the desired
> -     * file if one exists.
> +     * Here, {@code findFirst} returns an {@code Optional<URI>}, and then
> +     * {@code map} returns an {@code Optional<Path>} for the desired
> +     * URI if one exists.
>      *
>      * @param mapper the mapping function to apply to a value, if present
>      * @param <U> The type of the value returned from the mapping function