ArrayIndexOutOfBoundsException in SwaggerUiConfigParameters. Fixes #2509

springdoc-openapi-starter-common/src/main/java/org/springdoc/core/properties/SwaggerUiConfigParameters.java

@@ -25,11 +25,13 @@
 package org.springdoc.core.properties;
 
 import java.net.URL;
+import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
+import java.util.SortedMap;
 import java.util.TreeMap;
 import java.util.stream.Collectors;
 
@@ -260,7 +262,9 @@ public boolean isValidUrl(String url) {
 	 * @return the config parameters
 	 */
 	public Map<String, Object> getConfigParameters() {
-		final Map<String, Object> params = new TreeMap<>();
+		final TreeMap<String, Object> treeMap = new TreeMap<>();
+		SortedMap<String, Object> params = Collections.synchronizedSortedMap(treeMap);
+
 		// empty-string prevents swagger-ui default validation
 		params.put(VALIDATOR_URL_PROPERTY, validatorUrl != null ? validatorUrl : "");
 		org.springdoc.core.utils.SpringDocPropertiesUtils.put(CONFIG_URL_PROPERTY, configUrl, params);