8141652 : Rename methods Objects.nonNullElse* to requireNonNullElse*

[Roger Riggs]

A few of the proposed replacements of ?: with requireNonNullElse were 
unsuitable
because in the particular context, null is an allowed replacement value.

The webrev has been updated to revert changes:
  - two uses in 
jdk/src/java.base/share/classes/java/time/format/DateTimePrintContext.java 
(Line 145 and 160)
  - src/java.base/share/classes/java/time/temporal/TemporalQueries.java 
- reverted all changes

webrev:
http://cr.openjdk.java.net/~rriggs/webrev-require-non-null-8141652/

Thanks, Roger

p.s. the previous webrev is renamed: 
http://cr.openjdk.java.net/~rriggs/webrev-require-non-null-8141652-v1/



On 11/9/2015 2:35 PM, Roger Riggs wrote:
> Hi Stephen,
>
> On 11/6/2015 10:42 PM, Stephen Colebourne wrote:
>> Seems fine to me.
>>
>> I would have inlined the ZoneId change to one line:
>> String id = Objects.requireNonNullElse(aliasMap.get(zoneId), zoneId);
>> to avoid the local variable change, but no big deal.
>> Stephen
>
> Thanks, I'll fix that.
>
> Roger
>>
>>
>>
>> On 6 November 2015 at 20:24, Roger Riggs <Roger.Riggs at oracle.com> wrote:
>>> Please review the renaming of java.util.Object methods, the new 
>>> method names
>>> are:
>>>      public static <T> T requireNonNullElse(T obj, T defaultObj);
>>>      public static <T> T requireNonNullElseGet(T obj, Supplier<? 
>>> extends T>
>>> supplier);
>>>
>>> The only remaining possible gotcha for developers is the 
>>> requireNonNull(T,
>>> String)
>>> method that might be confused with requireNonNullElse(T, T). The longer
>>> name is probably the one you want.
>>> If you see a value that looks like an exception string, you've got 
>>> the wrong
>>> method.
>>>
>>> To validate some of the uses, I visually scanned src/java.base looking
>>> expressions of the pattern   (e1 != null) ? e1 : e2
>>> Most uses of the ternary operator involve either primitive types or
>>> conditions other than != null;
>>> quite a few involved returning null and so were not appropriate to be
>>> converted.
>>>
>>> 10 files contained relevant expressions:
>>>   - 2 should be using Objects.toString() to provide a default value 
>>> for a
>>> String.
>>>   - 2 can use the requireNonNullElseGet form to delay evaluating the
>>> alternative value.
>>>       (2 others were too early in the boot cycle to use lambda).
>>>   - The rest followed the expected pattern; though checking if 
>>> throwing an
>>> exception was extra work.
>>>
>>> Please review and comment.
>>>
>>> Webrev:
>>> http://cr.openjdk.java.net/~rriggs/webrev-require-non-null-8141652/
>>>
>>> Thanks for the detailed evaluation and discussion.
>>>
>>> Roger
>>>
>