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

[Mandy Chung]

Looks good to me.

Mandy

On 3/8/19 3:08 AM, Joe Darcy wrote:
> Hello,
> 
> The code in java.lang.Throwable has various explicit null checks that 
> could be rewritten to use Objects.requireNonNull.
> 
> Please review the patch below which implements this refactoring.
> 
> Thanks,
> 
> -Joe
> 
> diff -r 274361bd6915 src/java.base/share/classes/java/lang/Throwable.java
> --- a/src/java.base/share/classes/java/lang/Throwable.java    Thu Mar 07 
> 10:22:19 2019 +0100
> +++ b/src/java.base/share/classes/java/lang/Throwable.java    Fri Mar 08 
> 02:06:42 2019 -0800
> @@ -874,8 +874,7 @@
>           // Validate argument
>           StackTraceElement[] defensiveCopy = stackTrace.clone();
>           for (int i = 0; i < defensiveCopy.length; i++) {
> -            if (defensiveCopy[i] == null)
> -                throw new NullPointerException("stackTrace[" + i + "]");
> +            Objects.requireNonNull(defensiveCopy[i], "stackTrace[" + i 
> + "]");
>           }
> 
>           synchronized (this) {
> @@ -914,8 +913,7 @@
>                   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 +940,7 @@
>                   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 +1031,7 @@
>           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;
>