JDK-8191706: Proposal to add Reader::transferTo(Writer)

[Brian Goetz]

Looks good.

On 11/21/2017 2:56 PM, Patrick Reinhart wrote:
> Hi there out a the review [1] for  JDK-8066870, that will need some more
> working on, I created this specific issue to add an transferTo method to
> the java.io.Reader as it seems more clear as of the similarity to
> java.io.InputStream.transferTo(java.io.OutputStream) in terms of the API.
>
> To start the discussion I got the proposed API:
>
> /**
>   * 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 data. This method does not close either reader
>   * or writer.
>   * <p>
>   * 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 <i>asynchronously closed</i>, or the thread
>   * interrupted during the transfer, is highly reader and writer
>   * specific, and therefore not specified.
>   * <p>
>   * 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 data 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 {
> ....
> }
>
>
> -Patrick
>
>
> [1]
> http://mail.openjdk.java.net/pipermail/core-libs-dev/2017-November/050064.html
>
>
>
>