@Override
public Mono<HandlerResult> handle(ServerWebExchange exchange, Object handler) {
HandlerMethod handlerMethod = (HandlerMethod) handler;
Assert.state(this.methodResolver != null && this.modelInitializer != null, "Not initialized");
InitBinderBindingContext bindingContext = new InitBinderBindingContext(
getWebBindingInitializer(), this.methodResolver.getInitBinderMethods(handlerMethod));
InvocableHandlerMethod invocableMethod = this.methodResolver.getRequestMappingMethod(handlerMethod);
Function<Throwable, Mono<HandlerResult>> exceptionHandler =
ex -> handleException(ex, handlerMethod, bindingContext, exchange);
return this.modelInitializer
.initModel(handlerMethod, bindingContext, exchange)
.then(Mono.defer(() -> invocableMethod.invoke(exchange, bindingContext)))
.doOnNext(result -> result.setExceptionHandler(exceptionHandler))
.doOnNext(result -> bindingContext.saveModel())
.onErrorResume(exceptionHandler);
}