Support collection parameters in @query methods

This adds a test and fix so that collection parameters are supported and quoted correctly, at least for `Collection<String>`.

Previously the `StringQueryUtil` class would just call `.toString()` on the parameter and escape the `"` characters in the result, which would cause a syntax error in the query string.

This changes so that the class checks if the parameter is a `Collection` and if so starts a Json array and adds elements to it by calling `convert()` on each element.

Author: herder

src/main/java/org/springframework/data/elasticsearch/repository/support/StringQueryUtil.java

@@ -15,9 +15,12 @@
  */
 package org.springframework.data.elasticsearch.repository.support;
 
+import java.util.Collection;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import java.util.stream.Collectors;
+import org.springframework.core.convert.converter.Converter;
 import org.springframework.core.convert.support.GenericConversionService;
 import org.springframework.data.repository.query.ParameterAccessor;
 import org.springframework.util.NumberUtils;
@@ -53,20 +56,37 @@ private static String getParameterWithIndex(ParameterAccessor accessor, int inde
 		// noinspection ConstantConditions
 		if (parameter != null) {
 
-			if (conversionService.canConvert(parameter.getClass(), String.class)) {
-				String converted = conversionService.convert(parameter, String.class);
+      parameterValue = convert(parameter);
+    }
 
-				if (converted != null) {
-					parameterValue = converted;
-				}
-			} else {
-				parameterValue = parameter.toString();
-			}
-		}
-
-		parameterValue = parameterValue.replaceAll("\"", Matcher.quoteReplacement("\\\""));
 		return parameterValue;
 
 	}
 
+  private static String convert(Object parameter) {
+	  if (Collection.class.isAssignableFrom(parameter.getClass())) {
+	    Collection<?> collectionParam = (Collection<?>) parameter;
+	    StringBuilder sb = new StringBuilder("[");
+	    sb.append(collectionParam.stream().map(
+	        o -> "\"" + convert(o) + "\""
+      ).collect(Collectors.joining(",")));
+	    sb.append("]");
+	    return sb.toString();
+    } else {
+	    String parameterValue = "null";
+      if (conversionService.canConvert(parameter.getClass(), String.class)) {
+        String converted = conversionService.convert(parameter, String.class);
+
+        if (converted != null) {
+          parameterValue = converted;
+        }
+      } else {
+        parameterValue = parameter.toString();
+      }
+
+      parameterValue = parameterValue.replaceAll("\"", Matcher.quoteReplacement("\\\""));
+      return parameterValue;
+    }
+  }
+
 }

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

@@ -18,8 +18,10 @@
 import static org.assertj.core.api.Assertions.*;
 
 import java.lang.reflect.Method;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -51,6 +53,7 @@
 /**
  * @author Christoph Strobl
  * @author Peter-Josef Meisch
+ * @author Niklas Herder
  */
 @ExtendWith(MockitoExtension.class)
 public class ElasticsearchStringQueryUnitTests {
@@ -95,7 +98,20 @@ void shouldEscapeStringsInQueryParameters() throws Exception {
 				.isEqualTo("{\"bool\":{\"must\": [{\"match\": {\"prefix\": {\"name\" : \"hello \\\"Stranger\\\"\"}}]}}");
 	}
 
-	private org.springframework.data.elasticsearch.core.query.Query createQuery(String methodName, String... args)
+	@Test // #1858
+	@DisplayName("should escape Strings in collection query parameters")
+	void shouldEscapeStringsInCollectionsQueryParameters() throws Exception {
+
+	  final List<String> another_string = Arrays.asList("hello \"Stranger\"", "Another string");
+	  List<String> params = new ArrayList<>(another_string);
+	  org.springframework.data.elasticsearch.core.query.Query query = createQuery("findByNameIn", params);
+
+	  assertThat(query).isInstanceOf(StringQuery.class);
+	  assertThat(((StringQuery) query).getSource())
+	      .isEqualTo("{ 'bool' : { 'must' : { 'terms' : { 'name' : [\"hello \\\"Stranger\\\"\",\"Another string\"] } } } }");
+	}
+
+	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);
@@ -119,6 +135,9 @@ private interface SampleRepository extends Repository<Person, String> {
 		@Query("{ 'bool' : { 'must' : { 'term' : { 'name' : '?0' } } } }")
 		Person findByName(String name);
 
+		@Query("{ 'bool' : { 'must' : { 'terms' : { 'name' : ?0 } } } }")
+		Person findByNameIn(ArrayList<String> names);
+
 		@Query(value = "name:(?0, ?11, ?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?0, ?1)")
 		Person findWithRepeatedPlaceholder(String arg0, String arg1, String arg2, String arg3, String arg4, String arg5,
 				String arg6, String arg7, String arg8, String arg9, String arg10, String arg11);