RFR(JDK11/NIO) 8202285: (fs) Add a method to Files for comparing file contents

[Joe Wang]

Hi Jonathan,

hasSameContents does read better in English. This one was made 
isSameContent since I thought we'd want to stack it next to the existing 
isSameFile method since it's meant to be an extend to that method. I'd 
love to hear what people think about this. I'm open to change the name 
if there's a good consensus.

Cheers,
Joe

On 4/27/2018 4:01 AM, Jonathan Bluett-Duncan wrote:
> Hi Joe,
>
> I wonder if the method `isSameContent` should be named 
> `haveSameContents` so as to read more fluently in English.
>
> Cheers,
> Jonathan
>
> On 27 April 2018 at 11:58, Daniel Fuchs <daniel.fuchs at oracle.com 
> <mailto:daniel.fuchs at oracle.com>> wrote:
>
>     Hi Joe,
>
>     On the specification side, I think I would reword the API
>     documentation to first explain how the method checks the
>     content of the two files.
>
>     The fact that it doesn't check the actual content if
>     the two files are 'the same' is kind of an optimization.
>
>     So I would suggest to invert the order of the two paragraph
>     in the documentation, and combine them into one - something like:
>
>     1536      * <p>
>               * This method first calls {@link
>     #isSameFile(java.nio.file.Path, java.nio.file.Path)
>     isSameFile(path, path2)} to determine whether the two files are
>     the same.
>     1537      * If {@code isSameFile(path, path2)} returns false, this
>     method will proceed
>     1538      * to read the files and compare them byte by byte to
>     determine if they contain
>     1539      * the same contents.
>               * Otherwise, this method will return true without further
>               * processing.
>
>
>     On the implementation side I don't think it's reasonable to call
>     readAllBytes() and hold the content of the two files in memory
>     for comparing their content, especially if it's to discover that
>     the first byte differs.
>
>     Some lock-step reading of the two files would seem more appropriate.
>
>     best regards,
>
>     -- daniel
>
>
>
>
>
>     On 27/04/2018 05:51, Joe Wang wrote:
>
>         Hi,
>
>         Considering extending isSameFile to add isSameContent to
>         Files. Please review.
>
>         JBS: https://bugs.openjdk.java.net/browse/JDK-8202285
>         <https://bugs.openjdk.java.net/browse/JDK-8202285>
>
>         webrev:
>         http://cr.openjdk.java.net/~joehw/jdk11/8202285/webrev/
>         <http://cr.openjdk.java.net/%7Ejoehw/jdk11/8202285/webrev/>
>
>         specdiff:
>         http://cr.openjdk.java.net/~joehw/jdk11/8202285/specdiff/java/nio/file/Files.html
>         <http://cr.openjdk.java.net/%7Ejoehw/jdk11/8202285/specdiff/java/nio/file/Files.html>
>
>
>         Thanks,
>         Joe
>
>
>