Polishing.

Introduce isEmpty method for HintFunction for easier invocation avoiding negations on the call site.

See #3218
Original pull request: #4311

Author: mp911de

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/HintFunction.java

@@ -68,6 +68,15 @@ public boolean isPresent() {
 		return (hint instanceof String hintString && StringUtils.hasText(hintString)) || hint instanceof Bson;
 	}
 
+	/**
+	 * If a hint is not present, returns {@code true}, otherwise {@code false}.
+	 *
+	 * @return {@code true} if a hint is not present, otherwise {@code false}.
+	 */
+	public boolean isEmpty() {
+		return !isPresent();
+	}
+
 	/**
 	 * Apply the hint to consumers depending on the hint format if {@link #isPresent() present}.
 	 *
@@ -79,7 +88,7 @@ public boolean isPresent() {
 	public <R> void ifPresent(@Nullable CodecRegistryProvider registryProvider, Function<String, R> stringConsumer,
 			Function<Bson, R> bsonConsumer) {
 
-		if (!isPresent()) {
+		if (isEmpty()) {
 			return;
 		}
 		apply(registryProvider, stringConsumer, bsonConsumer);
@@ -97,7 +106,7 @@ public <R> void ifPresent(@Nullable CodecRegistryProvider registryProvider, Func
 	public <R> R apply(@Nullable CodecRegistryProvider registryProvider, Function<String, R> stringConsumer,
 			Function<Bson, R> bsonConsumer) {
 
-		if (!isPresent()) {
+		if (isEmpty()) {
 			throw new IllegalStateException("No hint present");
 		}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoTemplate.java

@@ -3226,7 +3226,7 @@ public FindIterable<Document> prepare(FindIterable<Document> iterable) {
 			Meta meta = query.getMeta();
 			HintFunction hintFunction = HintFunction.from(query.getHint());
 			if (query.getSkip() <= 0 && query.getLimit() <= 0 && ObjectUtils.isEmpty(query.getSortObject())
-					&& !hintFunction.isPresent() && !meta.hasValues() && !query.getCollation().isPresent()) {
+					&& hintFunction.isEmpty() && !meta.hasValues() && query.getCollation().isEmpty()) {
 				return cursorToUse;
 			}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoTemplate.java

@@ -3108,7 +3108,7 @@ public FindPublisher<Document> prepare(FindPublisher<Document> findPublisher) {
 			HintFunction hintFunction = HintFunction.from(query.getHint());
 			Meta meta = query.getMeta();
 			if (query.getSkip() <= 0 && query.getLimit() <= 0 && ObjectUtils.isEmpty(query.getSortObject())
-					&& !hintFunction.isPresent() && !meta.hasValues()) {
+					&& hintFunction.isEmpty() && !meta.hasValues()) {
 				return findPublisherToUse;
 			}