如何用Golang实现责任链模式动态管理请求_Golang 责任链模式综合实践

type Handler interface {
    SetNext(handler Handler) Handler
    Handle(request string) string
}

type BaseHandler struct {
    next Handler
}

func (b *BaseHandler) SetNext(handler Handler) Handler {
    b.next = handler
    return handler
}

func (b *BaseHandler) PassToNext(request string) string {
    if b.next == nil {
        return "No more handlers, request ended."
    }
    return b.next.Handle(request)
}

type AuthHandler struct {
    BaseHandler
}

func (a *AuthHandler) Handle(request string) string {
    if isValidToken(request) {
        return "Auth passed. " + a.PassToNext(request)
    }
    return "Auth failed."
}

type RoleCheckHandler struct {
    BaseHandler
}

func (r *RoleCheckHandler) Handle(request string) string {
    if hasAdminRole(request) {
        return "Role check passed. " + r.PassToNext(request)
    }
    return "Role check failed."
}

type ValidationHandler struct {
    BaseHandler
}

func (v *ValidationHandler) Handle(request string) string {
    if isValidJSON(request) {
        return "Validation passed. " + v.PassToNext(request)
    }
    return "Validation failed."
}

func main() {
    auth := &AuthHandler{}
    role := &RoleCheckHandler{}
    validate := &ValidationHandler{}

    // 构建链：先认证 → 再角色检查 → 最后数据校验
    auth.SetNext(role).SetNext(validate)

    request := "{\"token\": \"abc\", \"role\": \"admin\"}"

    result := auth.Handle(request)
    fmt.Println(result)
}

func NewDynamicChain(enabledHandlers []string) Handler {
    var head, current Handler

    for _, name := range enabledHandlers {
        var h Handler
        switch name {
        case "auth":
            h = &AuthHandler{}
        case "role":
            h = &RoleCheckHandler{}
        case "validate":
            h = &ValidationHandler{}
        }

        if head == nil {
            head = h
            current = h
        } else {
            current.SetNext(h)
            current = h
        }
    }

    return head
}