在 `yield` 后抛出 `HTTPException` 或类似的异常是很诱人的，但是**这不起作用**。

带有`yield`的依赖中的退出代码在响应发送之后执行，因此[异常处理程序](../handling-errors.md#install-custom-exception-handlers){.internal-link target=_blank}已经运行过。没有任何东西可以捕获退出代码（在`yield`之后）中的依赖抛出的异常。

所以，如果在`yield`之后抛出`HTTPException`，默认（或任何自定义）异常处理程序捕获`HTTPException`并返回HTTP 400响应的机制将不再能够捕获该异常。

这就是允许在依赖中设置的任何东西（例如数据库会话(DB session)）可以被后台任务使用的原因。

后台任务在响应发送之后运行。因此，无法触发`HTTPException`，因为甚至没有办法更改*已发送*的响应。

apiVersion: gateway.networking.k8s.io/v1beta1
kind: HTTPRoute
metadata:
  name: invalid-filter-wrong-field
spec:
  rules:
  - filters:
    - type: RequestHeaderModifier
      requestRedirect: 

class BrokenClass {
    Unknown1 field1
    Unknown2 field2

apiVersion: release-notes/v2
kind: feature
area: installation
issue: []
releaseNotes:
- |

apiVersion: release-notes/v2
kind: feature
area: installation
issue: []
releaseNotes:
- |

apiVersion: foo
kind: bar
metadata:
  name: no-errors
spec:
  field1: val1
  field2: val2
  nested:
  - name: nestedName
    nestedField1: val1`
	yamlOneErr := `---
apiVersion: foo
kind: bar
metadata:
  name: no-errors
spec:
  field1: val1
  field2: val2
  field2: val3
  nested:
  - name: nestedName
    nestedField1: val1`
	yamlManyErrs := `---

//   subscriptions might not match the index of the associated event in the
//   events buffer, both the subscription and event structs contain a userdata
//   field and when a subscription yields an event the userdata fields will
//   match.
// - there's no explicit timeout parameter, although a time limit can be added
//   by using "clock" subscriptions.

- Rule source classes must directly extend org.gradle.model.RuleSource
- Field field1 is not valid: Fields must be static final.
- Field field2 is not valid: Fields must be static final.

// if no field has a tag, tags may be nil.
func NewStruct(fields []*Var, tags []string) *Struct {
	var fset objset
	for _, f := range fields {
		if f.name != "_" && fset.insert(f) != nil {
			panic("multiple fields with the same name")
		}
	}
	if len(tags) > len(fields) {
		panic("more tags than fields")
	}
	s := &Struct{fields: fields, tags: tags}
	s.markComplete()
	return s
}

)

func TestNSQArgs_Validate(t *testing.T) {
	type fields struct {
		Enable      bool
		NSQDAddress xnet.Host
		Topic       string
		TLS         struct {
			Enable     bool
			SkipVerify bool
		}
	}
	tests := []struct {
		name    string
		fields  fields
		wantErr bool
	}{
		{
			name: "test1_missing_topic",
			fields: fields{
				Enable: true,
				NSQDAddress: xnet.Host{