Overload multiSearch method to support list of IndexCoordinates.

Original Pull Request #2436
Closes #2434

Author: AIRahimi

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

@@ -69,6 +69,7 @@
  * Elasticsearch client.
  *
  * @author Peter-Josef Meisch
+ * @author Hamid Rahimi
  * @since 4.4
  */
 public class ElasticsearchTemplate extends AbstractElasticsearchTemplate {
@@ -465,6 +466,29 @@ public List<SearchHits<?>> multiSearch(List<? extends Query> queries, List<Class
 		return doMultiSearch(multiSearchQueryParameters);
 	}
 
+	@Override
+	public List<SearchHits<?>> multiSearch(List<? extends Query> queries, List<Class<?>> classes,
+		   List<IndexCoordinates> indexes) {
+
+		Assert.notNull(queries, "queries must not be null");
+		Assert.notNull(classes, "classes must not be null");
+		Assert.notNull(indexes, "indexes must not be null");
+		Assert.isTrue(queries.size() == classes.size() && queries.size() == indexes.size(),
+				"queries, classes and indexes must have the same size");
+
+		List<MultiSearchQueryParameter> multiSearchQueryParameters = new ArrayList<>(queries.size());
+		Iterator<Class<?>> it = classes.iterator();
+		Iterator<IndexCoordinates> indexesIt = indexes.iterator();
+
+		for (Query query : queries) {
+			Class<?> clazz = it.next();
+			IndexCoordinates index = indexesIt.next();
+			multiSearchQueryParameters.add(new MultiSearchQueryParameter(query, clazz, index));
+		}
+
+		return doMultiSearch(multiSearchQueryParameters);
+	}
+
 	@SuppressWarnings({ "unchecked", "rawtypes" })
 	private List<SearchHits<?>> doMultiSearch(List<MultiSearchQueryParameter> multiSearchQueryParameters) {
 

src/main/java/org/springframework/data/elasticsearch/client/erhlc/ElasticsearchRestTemplate.java

@@ -112,6 +112,7 @@
  * @author Massimiliano Poggi
  * @author Farid Faoudi
  * @author Sijia Liu
+ * @author Hamid Rahimi
  * @since 4.4
  * @deprecated since 5.0
  */
@@ -558,6 +559,42 @@ public List<SearchHits<?>> multiSearch(List<? extends Query> queries, List<Class
 		return res;
 	}
 
+	@Override
+	public List<SearchHits<?>> multiSearch(List<? extends Query> queries, List<Class<?>> classes,
+		   List<IndexCoordinates> indexes) {
+
+		Assert.notNull(queries, "queries must not be null");
+		Assert.notNull(classes, "classes must not be null");
+		Assert.notNull(indexes, "indexes must not be null");
+		Assert.isTrue(queries.size() == classes.size() && queries.size() == indexes.size(),
+				"queries, classes and indexes must have the same size");
+
+		MultiSearchRequest request = new MultiSearchRequest();
+		Iterator<Class<?>> it = classes.iterator();
+		Iterator<IndexCoordinates> indexesIt = indexes.iterator();
+		for (Query query : queries) {
+			request.add(requestFactory.searchRequest(query, it.next(), indexesIt.next()));
+		}
+
+		MultiSearchResponse.Item[] items = getMultiSearchResult(request);
+
+		List<SearchHits<?>> res = new ArrayList<>(queries.size());
+		Iterator<Class<?>> it1 = classes.iterator();
+		Iterator<IndexCoordinates> indexesIt1 = indexes.iterator();
+		for (int i = 0; i < queries.size(); i++) {
+			Class entityClass = it1.next();
+			IndexCoordinates index = indexesIt1.next();
+
+			ReadDocumentCallback<?> documentCallback = new ReadDocumentCallback<>(elasticsearchConverter, entityClass, index);
+			SearchDocumentResponseCallback<SearchHits<?>> callback = new ReadSearchDocumentResponseCallback<>(entityClass,
+					index);
+
+			SearchResponse response = items[i].getResponse();
+			res.add(callback.doWith(SearchDocumentResponseBuilder.from(response, getEntityCreator(documentCallback))));
+		}
+		return res;
+	}
+
 	protected MultiSearchResponse.Item[] getMultiSearchResult(MultiSearchRequest request) {
 		MultiSearchResponse response = execute(client -> client.msearch(request, RequestOptions.DEFAULT));
 		MultiSearchResponse.Item[] items = response.getResponses();

src/main/java/org/springframework/data/elasticsearch/core/SearchOperations.java

@@ -30,6 +30,7 @@
  *
  * @author Peter-Josef Meisch
  * @author Sascha Woo
+ * @author Hamid Rahimi
  * @since 4.0
  */
 public interface SearchOperations {
@@ -127,11 +128,21 @@ default <T> SearchHit<T> searchOne(Query query, Class<T> clazz, IndexCoordinates
 	 *
 	 * @param queries the queries to execute
 	 * @param classes the entity classes used for property mapping
-	 * @param index the index to run the query against
+	 * @param index the index to run the queries against
 	 * @return list of SearchHits
 	 */
 	List<SearchHits<?>> multiSearch(List<? extends Query> queries, List<Class<?>> classes, IndexCoordinates index);
 
+	/**
+	 * Execute the multi search query against elasticsearch and return result as {@link List} of {@link SearchHits}.
+	 *
+	 * @param queries the queries to execute
+	 * @param classes the entity classes used for property mapping
+	 * @param indexes the indexes to run the queries against
+	 * @return list of SearchHits
+	 */
+	List<SearchHits<?>> multiSearch(List<? extends Query> queries, List<Class<?>> classes, List<IndexCoordinates> indexes);
+
 	/**
 	 * Execute the criteria query against elasticsearch and return result as {@link SearchHits}
 	 *

src/test/java/org/springframework/data/elasticsearch/core/ElasticsearchIntegrationTests.java

@@ -108,6 +108,7 @@
  * @author Sijia Liu
  * @author Haibo Liu
  * @author scoobyzhang
+ * @author Hamid Rahimi
  */
 @SpringIntegrationTest
 public abstract class ElasticsearchIntegrationTests {
@@ -1764,6 +1765,40 @@ public void shouldReturnDifferentEntityForMultiSearch() {
 		assertThat(searchHit1.getContent().getClass()).isEqualTo(Book.class);
 	}
 
+	@Test // #2434
+	public void shouldReturnDifferentEntityForMultiSearchWithMultipleIndexCoordinates() {
+
+		IndexOperations bookIndexOperations = operations.indexOps(Book.class);
+		bookIndexOperations.delete();
+		bookIndexOperations.createWithMapping();
+		bookIndexOperations.refresh();
+		IndexCoordinates bookIndex = IndexCoordinates.of("i-need-my-own-index");
+		operations.index(buildIndex(SampleEntity.builder().id("1").message("ab").build()),
+				IndexCoordinates.of(indexNameProvider.indexName()));
+		operations.index(buildIndex(Book.builder().id("2").description("bc").build()), bookIndex);
+		bookIndexOperations.refresh();
+
+		List<Query> queries = new ArrayList<>();
+		queries.add(getTermQuery("message", "ab"));
+		queries.add(getTermQuery("description", "bc"));
+
+		List<SearchHits<?>> searchHitsList = operations.multiSearch(queries,
+				Lists.newArrayList(SampleEntity.class, Book.class),
+				List.of(IndexCoordinates.of(indexNameProvider.indexName()),
+						IndexCoordinates.of(bookIndex.getIndexName())));
+
+		bookIndexOperations.delete();
+
+		SearchHits<?> searchHits0 = searchHitsList.get(0);
+		assertThat(searchHits0.getTotalHits()).isEqualTo(1L);
+		SearchHit<SampleEntity> searchHit0 = (SearchHit<SampleEntity>) searchHits0.getSearchHit(0);
+		assertThat(searchHit0.getContent().getClass()).isEqualTo(SampleEntity.class);
+		SearchHits<?> searchHits1 = searchHitsList.get(1);
+		assertThat(searchHits1.getTotalHits()).isEqualTo(1L);
+		SearchHit<Book> searchHit1 = (SearchHit<Book>) searchHits1.getSearchHit(0);
+		assertThat(searchHit1.getContent().getClass()).isEqualTo(Book.class);
+	}
+
 	@Test
 	public void shouldIndexDocumentForSpecifiedSource() {