Spring Cloud Gateway Hystrix fallback获取异常信息的处理

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
</dependency>

spring:
  cloud:
    gateway:
      discovery:
        locator:
          enabled: false
          lowerCaseServiceId: true
      routes:
        - id: auth-server
          uri: lb://MS-OAUTH2-SERVER
          predicates:
            - Path=/**
      default-filters:
        - name: Hystrix
          args:
            name: fallbackcmd
            fallbackUri: forward:/fallback

@RestController
@Slf4j
public class FallbackController {

    @RequestMapping(value = "/fallback")
    @ResponseStatus
    public Mono<Map<String, Object>> fallback(ServerWebExchange exchange, Throwable throwable) {
        Map<String, Object> result = new HashMap<>(3);
        ServerHttpRequest request = exchange.getRequest();
        log.error("接口调用失败，URL={}", request.getPath().pathWithinApplication().value(), throwable);
        result.put("code", 60002);
        result.put("data", null);
        result.put("msg", "接口调用失败!");
        return Mono.just(result);
    }
}

@RestController
@Slf4j
public class FallbackController {

    @RequestMapping(value = "/fallback")
    @ResponseStatus
    public Mono<Map<String, Object>> fallback(ServerWebExchange exchange) {
        Map<String, Object> result = new HashMap<>(3);
        result.put("code", 60002);
        result.put("data", null);
        Exception exception = exchange.getAttribute(ServerWebExchangeUtils.HYSTRIX_EXECUTION_EXCEPTION_ATTR);
        ServerWebExchange delegate = ((ServerWebExchangeDecorator) exchange).getDelegate();
        log.error("接口调用失败，URL={}", delegate.getRequest().getURI(), exception);
        if (exception instanceof HystrixTimeoutException) {
            result.put("msg", "接口调用超时");
        } else if (exception != null && exception.getMessage() != null) {
            result.put("msg", "接口调用失败: " + exception.getMessage());
        } else {
            result.put("msg", "接口调用失败");
        }
        return Mono.just(result);
    }
}

@Service
public class BookService {
    @Autowired
    public RestTemplate  restTemplate;
    @HystrixCommand(fallbackMethod = "addServiceFallback")
    public  Book   getBook( Integer  bookId ){
        return  restTemplate.getForObject("http://provider-service/boot/book?bookId={bookId}",Book.class , bookId);
    }
    public  String  addServiceFallback(){
        System.out.println("error addServiceFallback.... ");
        return  "error" ;
    }
}

public  String addServiceFallback(Integer  bookId){
    System.out.println("error addServiceFallback.... ");
    return  "error" ;
}

public  Book  addServiceFallback(Integer  bookId){
    System.out.println("error addServiceFallback.... ");
    return  new Book() ;
}

{"bookId":0,"bookName":null,"price":null,"publisher":null}