Upgrade to Elasticsearch 8.7.1.

Original Pull Request #2555
Closes #2541

pom.xml

@@ -23,7 +23,7 @@
 				<!-- version of the RestHighLevelClient	-->
 				<elasticsearch-rhlc>7.17.9</elasticsearch-rhlc>
 				<!-- version of the new ElasticsearchClient	-->
-				<elasticsearch-java>8.7.0</elasticsearch-java>
+				<elasticsearch-java>8.7.1</elasticsearch-java>
 
 				<log4j>2.18.0</log4j>
 				<!-- netty dependency can be removed once the WebClient code is gone -->

src/main/asciidoc/preface.adoc

@@ -38,7 +38,7 @@ built and tested.
 |===
 | Spring Data Release Train | Spring Data Elasticsearch | Elasticsearch | Spring Framework | Spring Boot
 | 2023.1 (?) | 5.2.x | 8.7.1 | 6.0.x | 3.1.x
-| 2023.0 (Ullmann) | 5.1.x | 8.7.0 | 6.0.x | 3.1.x
+| 2023.0 (Ullmann) | 5.1.x | 8.7.1 | 6.0.x | 3.1.x
 | 2022.0 (Turing) | 5.0.x | 8.5.3 | 6.0.x | 3.0.x
 | 2021.2 (Raj) | 4.4.xfootnote:oom[Out of maintenance] | 7.17.3 | 5.3.x | 2.7.x
 | 2021.1 (Q) | 4.3.xfootnote:oom[] | 7.15.2 | 5.3.x | 2.6.x

src/main/asciidoc/reference/elasticsearch-new.adoc

@@ -4,6 +4,8 @@
 [[new-features.5-2-0]]
 == New in Spring Data Elasticsearch 5.2
 
+* Upgrade to Elasticsearch 8.7.1
+
 [[new-features.5-1-0]]
 == New in Spring Data Elasticsearch 5.1
 

src/main/java/org/springframework/data/elasticsearch/client/elc/RequestConverter.java

@@ -16,18 +16,25 @@
 package org.springframework.data.elasticsearch.client.elc;
 
 import static org.springframework.data.elasticsearch.client.elc.TypeUtils.*;
-import static org.springframework.util.CollectionUtils.isEmpty;
+import static org.springframework.util.CollectionUtils.*;
 
-import co.elastic.clients.elasticsearch._types.*;
+import co.elastic.clients.elasticsearch._types.Conflicts;
+import co.elastic.clients.elasticsearch._types.FieldValue;
+import co.elastic.clients.elasticsearch._types.InlineScript;
+import co.elastic.clients.elasticsearch._types.OpType;
+import co.elastic.clients.elasticsearch._types.SortOptions;
+import co.elastic.clients.elasticsearch._types.SortOrder;
+import co.elastic.clients.elasticsearch._types.VersionType;
+import co.elastic.clients.elasticsearch._types.WaitForActiveShardOptions;
 import co.elastic.clients.elasticsearch._types.mapping.FieldType;
 import co.elastic.clients.elasticsearch._types.mapping.RuntimeField;
 import co.elastic.clients.elasticsearch._types.mapping.RuntimeFieldType;
 import co.elastic.clients.elasticsearch._types.query_dsl.FieldAndFormat;
 import co.elastic.clients.elasticsearch._types.query_dsl.Like;
-import co.elastic.clients.elasticsearch.cluster.*;
 import co.elastic.clients.elasticsearch.cluster.DeleteComponentTemplateRequest;
 import co.elastic.clients.elasticsearch.cluster.ExistsComponentTemplateRequest;
 import co.elastic.clients.elasticsearch.cluster.GetComponentTemplateRequest;
+import co.elastic.clients.elasticsearch.cluster.HealthRequest;
 import co.elastic.clients.elasticsearch.cluster.PutComponentTemplateRequest;
 import co.elastic.clients.elasticsearch.core.*;
 import co.elastic.clients.elasticsearch.core.bulk.BulkOperation;
@@ -52,7 +59,13 @@ import java.io.ByteArrayInputStream;
 import java.io.StringReader;
 import java.nio.charset.StandardCharsets;
 import java.time.Duration;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
@@ -1537,8 +1550,11 @@ class RequestConverter {
 		builder //
 				.suggest(query.getSuggester()) //
 				.collapse(query.getFieldCollapse()) //
-				.sort(query.getSortOptions()) //
-				.knn(query.getKnnQuery());
+				.sort(query.getSortOptions());
+
+		if (query.getKnnQuery() != null) {
+			builder.knn(query.getKnnQuery());
+		}
 
 		if (!isEmpty(query.getAggregations())) {
 			builder.aggregations(query.getAggregations());

src/test/resources/testcontainers-elasticsearch.properties

@@ -15,7 +15,7 @@
 #
 #
 sde.testcontainers.image-name=docker.elastic.co/elasticsearch/elasticsearch
-sde.testcontainers.image-version=8.7.0
+sde.testcontainers.image-version=8.7.1
 #
 #
 # needed as we do a DELETE /* at the end of the tests, will be required from 8.0 on, produces a warning since 7.13