FallbackHeaders GatewayFilter Factory

FallbackHeaders 工厂允许你向在外部应用程序中转发至 fallbackUri 的请求的头中添加 Spring Cloud CircuitBreaker 执行异常详细信息，如下面的场景所示：

The FallbackHeaders factory lets you add Spring Cloud CircuitBreaker execution exception details in the headers of a request forwarded to a fallbackUri in an external application, as in the following scenario:

application.yml
spring:
  cloud:
    gateway:
      routes:
      - id: ingredients
        uri: lb://ingredients
        predicates:
        - Path=//ingredients/**
        filters:
        - name: CircuitBreaker
          args:
            name: fetchIngredients
            fallbackUri: forward:/fallback
      - id: ingredients-fallback
        uri: http://localhost:9994
        predicates:
        - Path=/fallback
        filters:
        - name: FallbackHeaders
          args:
            executionExceptionTypeHeaderName: Test-Header

在此示例中，在运行断路器时出现执行异常后，请求将转发到运行在 localhost:9994 上的应用程序中的 fallback 端点或处理程序。FallbackHeaders 筛选器会将包含异常类型、消息和（如果可用）根异常类型和消息的头添加到该请求中。

In this example, after an execution exception occurs while running the circuit breaker, the request is forwarded to the fallback endpoint or handler in an application running on localhost:9994. The headers with the exception type, message and (if available) root cause exception type and message are added to that request by the FallbackHeaders filter.

你可以通过设置以下参数的值（及其默认值）来覆盖配置中的头名称：

You can overwrite the names of the headers in the configuration by setting the values of the following arguments (shown with their default values):

  • executionExceptionTypeHeaderName ("Execution-Exception-Type")

  • executionExceptionMessageHeaderName ("Execution-Exception-Message")

  • rootCauseExceptionTypeHeaderName ("Root-Cause-Exception-Type")

  • rootCauseExceptionMessageHeaderName ("Root-Cause-Exception-Message")

有关断路器和网关的更多信息，请参阅 Spring Cloud CircuitBreaker Factory section。

For more information on circuit breakers and the gateway see the Spring Cloud CircuitBreaker Factory section.