Lower log level for ResponseStatusException

Issue: SPR-16049

spring-web/src/main/java/org/springframework/web/server/ResponseStatusException.java

@@ -87,9 +87,9 @@ public class ResponseStatusException extends NestedRuntimeException {
 	}
 
 	@Override
-	@Nullable
 	public String getMessage() {
-		String msg = "Response status " + this.status + (this.reason != null ? " with reason \"" + reason + "\"" : "");
+		String msg = "Response status " + this.status +
+				(this.reason != null ? " with reason \"" + reason + "\"" : "");
 		return NestedExceptionUtils.buildMessage(msg, getCause());
 	}
 

spring-web/src/main/java/org/springframework/web/server/handler/ResponseStatusExceptionHandler.java

@@ -35,14 +35,13 @@ public class ResponseStatusExceptionHandler implements WebExceptionHandler {
 
 	private static final Log logger = LogFactory.getLog(ResponseStatusExceptionHandler.class);
 
+
 	@Override
 	public Mono<Void> handle(ServerWebExchange exchange, Throwable ex) {
 		if (ex instanceof ResponseStatusException) {
 			exchange.getResponse().setStatusCode(((ResponseStatusException) ex).getStatus());
-			if (ex.getMessage() != null) {
-				logger.error(ex.getMessage());
-			}
-			return Mono.empty();
+			logger.debug(ex.getMessage());
+			return exchange.getResponse().setComplete();
 		}
 		return Mono.error(ex);
 	}