Fix handling of array-of-strings parameters for @Query-annotated queries.

Fixes spring-projects#2135

Author: diamondT

src/main/java/org/springframework/data/elasticsearch/repository/query/ConvertingParameterAccessor.java

@@ -15,8 +15,8 @@
  */
 package org.springframework.data.elasticsearch.repository.query;
 
+import java.util.Collection;
 import java.util.Iterator;
-import java.util.Optional;
 
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.domain.Sort;
@@ -86,6 +86,10 @@ private Object getConvertedValue(Object value) {
 			return "null";
 		}
 
+		if (Collection.class.isAssignableFrom(value.getClass())) {
+			return value;
+		}
+
 		if (converter.getConversionService().canConvert(value.getClass(), String.class)) {
 			return converter.getConversionService().convert(value, String.class);
 		}

src/test/java/org/springframework/data/elasticsearch/repository/query/ReactiveElasticsearchStringQueryUnitTests.java

@@ -144,14 +144,29 @@ void shouldUseConverterOnParameters() throws Exception {
 				.isEqualTo("{ 'bool' : { 'must' : { 'term' : { 'car' : 'Toyota-Prius' } } } }");
 	}
 
+	@Test // #1866
+	@DisplayName("should handle array-of-strings parameters correctly")
+	void shouldHandleArrayOfStringsParametersCorrectly() throws Exception {
+
+		List<String> otherNames = List.of("Wesley", "Emmett");
+
+		org.springframework.data.elasticsearch.core.query.Query query = createQuery("findByOtherNames", otherNames);
+
+		assertThat(query).isInstanceOf(StringQuery.class);
+		assertThat(((StringQuery) query).getSource())
+				.isEqualTo("{ 'bool' : { 'must' : { 'terms' : { 'otherNames' : [\"Wesley\",\"Emmett\"] } } } }");
+	}
+
 	private org.springframework.data.elasticsearch.core.query.Query createQuery(String methodName, Object... args)
 			throws NoSuchMethodException {
 
-		Class<?>[] argTypes = Arrays.stream(args).map(Object::getClass).toArray(Class[]::new);
+		Class<?>[] argTypes = Arrays.stream(args).map(Object::getClass)
+				.map(clazz -> Collection.class.isAssignableFrom(clazz) ? List.class : clazz).toArray(Class[]::new);
 		ReactiveElasticsearchQueryMethod queryMethod = getQueryMethod(methodName, argTypes);
 		ReactiveElasticsearchStringQuery elasticsearchStringQuery = queryForMethod(queryMethod);
 
-		return elasticsearchStringQuery.createQuery(new ElasticsearchParametersParameterAccessor(queryMethod, args));
+		return elasticsearchStringQuery.createQuery(new ConvertingParameterAccessor(operations.getElasticsearchConverter(),
+				new ElasticsearchParametersParameterAccessor(queryMethod, args)));
 	}
 
 	private ReactiveElasticsearchStringQuery queryForMethod(ReactiveElasticsearchQueryMethod queryMethod) {
@@ -195,6 +210,9 @@ Person findWithRepeatedPlaceholder(String arg0, String arg1, String arg2, String
 		@Query("{ 'bool' : { 'must' : { 'term' : { 'car' : '?0' } } } }")
 		Mono<Person> findByCar(Car car);
 
+		@Query("{ 'bool' : { 'must' : { 'terms' : { 'otherNames' : ?0 } } } }")
+		Flux<Person> findByOtherNames(List<String> otherNames);
+
 	}
 
 	/**
@@ -211,6 +229,8 @@ public class Person {
 
 		@Nullable private String name;
 
+		@Nullable private List<String> otherNames;
+
 		@Nullable
 		@Field(type = FieldType.Nested) private List<Car> car;
 
@@ -235,6 +255,15 @@ public void setName(String name) {
 			this.name = name;
 		}
 
+		@Nullable
+		public List<String> getOtherNames() {
+			return otherNames;
+		}
+
+		public void setOtherNames(List<String> otherNames) {
+			this.otherNames = otherNames;
+		}
+
 		@Nullable
 		public List<Car> getCar() {
 			return car;

src/test/java/org/springframework/data/elasticsearch/repository/support/SimpleReactiveElasticsearchRepositoryIntegrationTests.java

@@ -588,6 +588,21 @@ void derivedDeleteMethodShouldBeExecutedCorrectly() {
 		assertThat(documentWithIdExistsInIndex("id-three").block()).isTrue();
 	}
 
+	@Test // #2135
+	void FluxOfSearchHitForArrayQuery() {
+		bulkIndex(new SampleEntity("id-one", "message1"), //
+				new SampleEntity("id-two", "message2"), //
+				new SampleEntity("id-three", "message3")) //
+						.block();
+
+		repository.findAllViaAnnotatedQueryByMessageIn(List.of("message1", "message3")) //
+				.as(StepVerifier::create) //
+				.consumeNextWith(it -> assertThat(it.getId()).isEqualTo("id-one")) //
+				.consumeNextWith(it -> assertThat(it.getId()).isEqualTo("id-three")) //
+				.verifyComplete();
+
+	}
+
 	Mono<Void> bulkIndex(SampleEntity... entities) {
 		return operations.saveAll(Arrays.asList(entities), IndexCoordinates.of(indexNameProvider.indexName())).then();
 	}
@@ -627,6 +642,9 @@ interface ReactiveSampleEntityRepository extends ReactiveCrudRepository<SampleEn
 
 		@CountQuery(value = "{\"bool\": {\"must\": [{\"term\": {\"message\": \"?0\"}}]}}")
 		Mono<Long> retrieveCountByText(String message);
+
+		@Query("{ \"terms\": { \"message\": ?0 } }")
+		Flux<SampleEntity> findAllViaAnnotatedQueryByMessageIn(List<String> messages);
 	}
 
 	@Document(indexName = "#{@indexNameProvider.indexName()}")