JDK 13 RFR of JDK-8220346: Refactor java.lang.Throwable to use Objects.requireNonNull

[Mandy Chung]

The updated patch looks good.

Mandy

On 3/11/19 9:29 AM, Joe Darcy wrote:
> Hello,
> 
> Always surprising how much discussion an (apparently) simple refactoring 
> can generate!
> 
> Thanks to Tagir for spotting this issue.
> 
> For completeness, the two-argument forms of requireNonNull which takes a 
> Supplier<String> is not applicable to preserve the message behavior 
> since the loop counter i is not final or effectively final:
> 
>      Objects.requireNonNull(defensiveCopy[i],  () -> "stackTrace[" + i + 
> "]");
> 
> Therefore, I'll revert this use of requireNonNull in Throwable but keep 
> the other three:
> 
> diff -r 289fd6cb7480 src/java.base/share/classes/java/lang/Throwable.java
> --- a/src/java.base/share/classes/java/lang/Throwable.java    Mon Mar 11 
> 15:34:16 2019 +0100
> +++ b/src/java.base/share/classes/java/lang/Throwable.java    Mon Mar 11 
> 09:28:51 2019 -0700
> @@ -914,8 +914,7 @@
>                   for (Throwable t : suppressedExceptions) {
>                       // Enforce constraints on suppressed exceptions in
>                       // case of corrupt or malicious stream.
> -                    if (t == null)
> -                        throw new 
> NullPointerException(NULL_CAUSE_MESSAGE);
> +                    Objects.requireNonNull(t, NULL_CAUSE_MESSAGE);
>                       if (t == this)
>                           throw new 
> IllegalArgumentException(SELF_SUPPRESSION_MESSAGE);
>                       suppressed.add(t);
> @@ -942,8 +941,7 @@
>                   stackTrace = null;
>               } else { // Verify stack trace elements are non-null.
>                   for(StackTraceElement ste : stackTrace) {
> -                    if (ste == null)
> -                        throw new NullPointerException("null 
> StackTraceElement in serial stream. ");
> +                    Objects.requireNonNull(ste, "null StackTraceElement 
> in serial stream.");
>                   }
>               }
>           } else {
> @@ -1034,8 +1032,7 @@
>           if (exception == this)
>               throw new 
> IllegalArgumentException(SELF_SUPPRESSION_MESSAGE, exception);
> 
> -        if (exception == null)
> -            throw new NullPointerException(NULL_CAUSE_MESSAGE);
> +        Objects.requireNonNull(exception, NULL_CAUSE_MESSAGE);
> 
>           if (suppressedExceptions == null) // Suppressed exceptions not 
> recorded
>               return;
> 
> Thanks,
> 
> -Joe