RFR: 8251989: Hex formatting and parsing utility [v9]

[Marcono1234]

On Tue, 27 Oct 2020 03:09:32 GMT, Roger Riggs <rriggs at openjdk.org> wrote:

>> java.util.HexFormat utility:
>> 
>>  - Format and parse hexadecimal strings, with parameters for delimiter, prefix, suffix and upper/lowercase
>>  - Static factories and builder methods to create HexFormat copies with modified parameters.
>>  - Consistent naming of methods for conversion of byte arrays to formatted strings and back: formatHex and parseHex
>>  - Consistent naming of methods for conversion of primitive types: toHexDigits... and fromHexDigits...
>>  - Prefix and suffixes now apply to each formatted value, not the string as a whole
>>  - Using java.util.Appendable as a target for buffered conversions so output to Writers and PrintStreams
>>    like System.out are supported in addition to StringBuilder. (IOExceptions are converted to unchecked exceptions)
>>  - Immutable and thread safe, a "value-based" class
>> 
>> See the [HexFormat javadoc](http://cr.openjdk.java.net/~rriggs/8251989-hex-formatter/java.base/java/util/HexFormat.html) for details.
>> 
>> Review comments and suggestions welcome.
>
> Roger Riggs has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - The HexFormat API indexing model for array and string ranges is changed
>    to describe the range using 'fromIndex (inclusive)' and 'toIndex (exclusive)'.
>    
>    Initially, it was specified as 'index' and 'length'. However, both byte arrays
>    and strings used in the HexFormat API typically use fromIndex and toIndex
>    to describe ranges.  Using the same indexing model can prevent mistakes.
>    
>    The change affects the methods and corresponding tests:
>    
>        formatHex(byte[] bytes, int fromIndex, int toIndex)
>        formatHex(A out, byte[] bytes, int fromIndex, int toIndex)
>        parseHex(char[] chars, int fromIndex, int toIndex)
>        parseHex(CharSequence string, int fromIndex, int toIndex)
>        fromHexDigits(CharSequence string, int fromIndex, int toIndex)
>        fromHexDigitsToLong(CharSequence string, int fromIndex, int toIndex)
>  - - Added @see and @link references to Integer.toHexString and Long.toHexString
>    - Clarified parsing is case insensistive in various parse and fromXXX methods
>    - Source level cleanup based on review comments
>    - Expanded some javadoc tag text to make it more descriptive
>    - Consistent use of 'hexadecimal' vs 'hex'

The changes look good, especially that `Integer.toHexString` and `Long.toHexString` now link to this new class!

src/java.base/share/classes/java/lang/Integer.java line 260:

> 258:      *  {@code Integer.toHexString(n).toUpperCase()}
> 259:      * </blockquote>
> 260:      * <p>

Is this needed? `@apiNote` is a block tag so should create a paragraph on its own.

src/java.base/share/classes/java/lang/Long.java line 295:

> 293:      *  {@code Long.toHexString(n).toUpperCase()}
> 294:      * </blockquote>
> 295:      * <p>

Is this needed? `@apiNote` is a block tag so should create a paragraph on its own.

src/java.base/share/classes/java/util/HexFormat.java line 316:

> 314:      * @param bytes a non-null array of bytes
> 315:      * @param fromIndex the initial index of the range, inclusive
> 316:      * @param toIndex the final index of the range, exclusive.

Suggestion:

     * @param toIndex the final index of the range, exclusive

The period at the end is inconsistent.
Applies to the other `@param toIndex` as well.

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PR: https://git.openjdk.java.net/jdk/pull/482