On Mon, 17 Jun 2024 18:17:06 GMT, Justin Lu <j...@openjdk.org> wrote:
>>> I second Justin's suggestion here. The change should benefit every
>>> implementation in the JDK, not only NumberFormat. Also, I might suggest
>>> renaming the new class, as it is kind of long/redundant. How about using
>>> something as simple as "StringBuf"?
>>
>> Thanks for your comment. The long name bother me for a while. I have changed
>> it to ""StringBuf".
>
> Hi @lingjun-cg
>
> Thanks for your work here.
>
> While this would benefit the performance of NumberFormat subclasses, we are
> hoping that if we are going to make the internal switch to StringBuilder, we
> can also make similar changes to other Format subclasses as well where
> applicable. So, we would want `isInternalSubclass()` to be defined at the
> Format level. Some methods that I can immediately think of would be `String
> DateFormat.format(Date date)`, `String ListFormat.format(List<String> input)`
> and, `String MessageFormat.format(Object obj)`.
>
> I believe @naotoj shares the same sentiment.
@justin-curtis-lu The method `isInternalSubclass` in `DecimalFormat` already
pulls up to `Format`.
@liach @naotoj Using `Appendable & CharSequence` instead of an interface with a
limited method is a great idea. Following this idea, I have updated the PR. But
there are some notes when implementing the idea.
1. Rename `format` to `formatWithGeneric` in DecimalFormat that accepts
StringBuilder. If not that, throw a StackOverflowException when run with
`DecimalFormat.format(double)`. If not rename the format, there are 2 methods
in DecimalFormat:
```
@Override
public StringBuffer format(double number, StringBuffer result,
FieldPosition fieldPosition) {
return format(number, result, fieldPosition);
}
@Override
<T extends Appendable & CharSequence> T format(double number, T result,
FieldPosition fieldPosition)
{
}
Because the second parameter type `StringBuffer` of the 1st method is more
concrete than type `T` of the 2nd method, so the 1st method will call itself
recursively.
2. The `Appendable#append(java.lang.CharSequence)` method can throws
IOException, so there is some messy code handling IOException.
-------------
PR Comment: https://git.openjdk.org/jdk/pull/19513#issuecomment-2175778275
