On Fri, 18 Jun 2021 05:54:01 GMT, Yi Yang <yy...@openjdk.org> wrote:
>> After JDK-8265518(#3615), it's possible to replace all variants of
>> checkIndex by
>> Objects.checkIndex/Objects.checkFromToIndex/Objects.checkFromIndexSize in
>> the whole JDK codebase.
>
> Yi Yang has updated the pull request incrementally with one additional commit
> since the last revision:
>
> restore IndexOfOufBoundsException; split exception line
@kahatlen for cases earlier in VM startup you need to avoid method references
and lambda expressions. See the implementation of
`outOfBoundsExceptionFormatter`, and see the usage in `VarHandle` for two
examples.
Custom exception formaters should ideally be constants held in static final
fields.
I think the API complexity comes down to whether it is necessary to preserve
existing exception messages or not when converting existing code to use the
precondition methods. The API is designed to do that and composes reasonably
well for default exception messages with a non-default exceptions. We could
argue (i would!) it is preferable to have a consistent exception messages for
index out of bounds exceptions, thereby we could collapse and simplify, but
this is sometimes considered a change in behaviour.
src/java.base/share/classes/java/util/Base64.java line 935:
> 933: throw new IOException("Stream is closed");
> 934: Preconditions.checkFromIndexSize(len, off, b.length,
> 935:
> Preconditions.outOfBoundsExceptionFormatter(ArrayIndexOutOfBoundsException::new));
`outOfBoundsExceptionFormatter` will allocate. Store the result of
`Preconditions.outOfBoundsExceptionFormatter(ArrayIndexOutOfBoundsException::new))`
in a public static final on `Preconditions`, and replace the method ref with a
inner class (thereby making it usable earlier at VM startup.
-------------
PR: https://git.openjdk.java.net/jdk/pull/4507
