RFR: 8274319: Replace usages of Collections.sort with List.sort call in jdk.jfr

[Erik Gahlin]

On Sat, 25 Sep 2021 11:08:16 GMT, Andrey Turbanov <github.com+741251+turbanoff at openjdk.org> wrote:

> Collections.sort is just a wrapper, so it is better to use an instance method directly.
> 
> Also Comparator's implementation can be cleaned up with help of static methods in `Comparator` class.
> E.g `(u, v) -> Long.compare(v.count, u.count)` can be replaced with `Comparator.comparingLong(v -> v.count)`

Changes requested by egahlin (Reviewer).

src/jdk.jfr/share/classes/jdk/jfr/internal/dcmd/AbstractDCmd.java line 172:

> 170:     protected final List<Recording> getRecordings() {
> 171:         List<Recording> list = new ArrayList<>(getFlightRecorder().getRecordings());
> 172:         list.sort(Comparator.comparing(Recording::getId));

Use Comparator.comparingLong instead?

src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Summary.java line 146:

> 144:             println(" Duration: " + (totalDuration + 500_000_000) / 1_000_000_000 + " s");
> 145:             List<Statistics> statsList = new ArrayList<>(stats.values());
> 146:             statsList.sort(Comparator.comparingLong(v -> v.count));

This looks incorrect. the order is reversed compared to before.

Events with a high count should appear on top.

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PR: https://git.openjdk.java.net/jdk/pull/5696