[spring] Fix postgres deadlock

The now fixed deadlock issue was only visible
under high concurrency and was generating errors
and leading to lower than expected performance.

Sorting the worlds before updating them allows
to avoid this issue.

Author: sdeleuze

frameworks/Java/spring/src/main/java/hello/web/DbHandler.java

@@ -1,6 +1,7 @@
 package hello.web;
 
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.List;
 
 import hello.Utils;
@@ -52,6 +53,7 @@ ServerResponse updates(ServerRequest request) {
 					world.randomNumber = randomNumber;
 					return world;
 				}).limit(queries)
+				.sorted(Comparator.comparingInt(w -> w.id))
 				.toList();
 		dbRepository.updateWorlds(worlds);
 		return ServerResponse.ok()