先給出接口
type Handler interface {
do()
SetNext(handler Handler) Handler
Run()
}
// 用以復用
type Next struct {
nextHandler Handler
}
func (n *Next) SetNext(handler Handler) Handler {
n.nextHandler = handler
return handler
}
func (n *Next) Run() {
if n.nextHandler != nil {
n.nextHandler.do()
n.nextHandler.Run()
}
}
具體處理的實例
// RootHandler do nothing
type RootHandler struct {
Next
}
// 根結點不做事
func (h RootHandler) do() {
// do nothing
}
type OneHandler struct {
Next
}
func (o OneHandler) do() {
fmt.Println("handler one do something")
}
type TwoHandler struct {
Next
}
func (o TwoHandler) do() {
fmt.Println("handler two do something")
}
使用
root := &RootHandler{}
// 執行順序一目了然
root.SetNext(&TwoHandler{}).
SetNext(&OneHandler{})
root.Run()
