具有以下结构:
package dto
type CapacityResponse struct{
Val int
Err error
TransactionID string
}
func (r *CapacityResponse) GetError() (error) {
return r.Err
}
func (r *CapacityResponse) SetError(err error) {
r.Err = err
}
func (r *CapacityResponse) Read() interface{} {
return r.Val
}
func (r *CapacityResponse) GetTransactionId() string {
return r.TransactionID
}
它的界面:
package dto
type Responder interface {
Read() (interface{})
GetError() (error)
SetError(error)
GetTransactionId() (string)
}
以及以下逻辑:
func handler(w http.ResponseWriter, r *http.Request) {
cr := request2CacheRequest(r)
responseChan := make(chan dto.Responder)
go func() {
responder := processReq(cr)
responseChan <- responder
}()
go func() {
for r := range responseChan {
if (r.GetTransactionId() == cr.TransactionID) {
switch r.(type) {
//case dto.KeysResponse:
//case dto.GetResponse:
//case dto.RemoveResponse:
//case dto.SetResponse:
case dto.CapacityResponse:
if i, ok := r.Read().(int); ok {
fmt.Fprintf(w, fmt.Sprintf("{'capasity': %d, 'err': %s}", i, r.GetError()))
}
}
}
}
}()
}
我遇到异常:
impossible type switch case: r (type dto.Responder) cannot have dynamic type dto.CapacityResponse (missing GetError method)
你能帮我理解这里出了什么问题吗？
最佳答案
错误消息是说 dto.Responder 值不能包含 dto.CapacityResponse，因为 dto.CapacityResponse 缺少 dto.Responder 方法之一 (GetError)。
指针类型实现接口(interface)。将大小写更改为:
case *dto.CapacityResponse:
关于go - 不可能类型开关盒 : cannot have dynamic type，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/48967199/