Polish

Closes gh-1842

oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/JdbcOAuth2AuthorizationService.java

@@ -766,8 +766,7 @@ public class JdbcOAuth2AuthorizationService implements OAuth2AuthorizationServic
 
 		@Override
 		protected void doSetValue(PreparedStatement ps, int parameterPosition, Object argValue) throws SQLException {
-			if (argValue instanceof SqlParameterValue) {
-				SqlParameterValue paramValue = (SqlParameterValue) argValue;
+			if (argValue instanceof SqlParameterValue paramValue) {
 				if (paramValue.getSqlType() == Types.BLOB) {
 					if (paramValue.getValue() != null) {
 						Assert.isInstanceOf(byte[].class, paramValue.getValue(),

oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/authentication/OAuth2ClientAuthenticationToken.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2022 the original author or authors.
+ * Copyright 2020-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -92,7 +92,7 @@ public class OAuth2ClientAuthenticationToken extends AbstractAuthenticationToken
 		this.registeredClient = registeredClient;
 		this.clientAuthenticationMethod = clientAuthenticationMethod;
 		this.credentials = credentials;
-		this.additionalParameters = Collections.unmodifiableMap(Collections.emptyMap());
+		this.additionalParameters = Collections.emptyMap();
 		setAuthenticated(true);
 	}