深入理解Go语言接口：值接收者与指针接收者的差异与实践

package main

import (
    "fmt"
    "github.com/ant0ine/go-json-rest/rest" // 假设这个包是可用的
    "net/http"
)

// App 结构体定义
type App struct {
    Id   string
    Name string
}

// ResourceController 接口定义
type ResourceController interface {
    Show(w *rest.ResponseWriter, req *rest.Request)
    Create(w *rest.ResponseWriter, req *rest.Request)
    Update(w *rest.ResponseWriter, req *rest.Request)
    Delete(w *rest.ResponseWriter, req *rest.Request)
}

// AppController 类型
type AppController struct{}

// AppController 实现 ResourceController 接口的方法，均使用指针接收者
func (self *AppController) Show(w *rest.ResponseWriter, r *rest.Request) {
    app := App{
        Id:   r.PathParam("id"),
        Name: "Antoine",
    }
    w.WriteJson(&app)
}

func (self *AppController) Create(w *rest.ResponseWriter, r *rest.Request) {
    app := App{
        Id:   r.PathParam("id"),
        Name: "Antoine",
    }
    w.WriteJson(&app)
}

func (self *AppController) Update(w *rest.ResponseWriter, r *rest.Request) {
    app := App{
        Id:   r.PathParam("id"),
        Name: "Antoine",
    }
    w.WriteJson(&app)
}

func (self *AppController) Delete(w *rest.ResponseWriter, r *rest.Request) {
    app := App{
        Id:   r.PathParam("id"),
        Name: "Antoine",
    }
    w.WriteJson(&app)
}

// MyResourceHandler 结构体及 AddResource 方法（简化版，仅为说明问题）
type MyResourceHandler struct {
    rest.ResourceHandler
}

func (self *MyResourceHandler) AddResource(name string, c ResourceController) error {
    // 实际路由设置逻辑省略，此处仅关注接口参数
    fmt.Printf("Adding resource %s with controller of type %T\n", name, c)
    return nil
}

func main() {
    handler := MyResourceHandler{}
    controler := AppController{} // 问题所在：这里创建的是一个值类型变量

    // 尝试将值类型变量传递给期望 ResourceController 接口参数的方法
    // 编译时会报错：AppController does not implement ResourceController (Create method requires pointer receiver)
    err := handler.AddResource("app", controler) 
    if err != nil {
        fmt.Println("Error:", err)
    }

    // http.ListenAndServe(":9008", &handler) // 实际应用中会启动HTTP服务
}

./main.go:93: cannot use controler (type AppController) as type ResourceController in function argument:
    AppController does not implement ResourceController (Create method requires pointer receiver)

func main() {
    handler := MyResourceHandler{}
    // 解决方案：将值类型变量改为指针类型变量
    controler := &AppController{} // 注意这里的 '&' 符号

    // 现在，&AppController{} (即 *AppController 类型) 满足 ResourceController 接口
    err := handler.AddResource("app", controler) 
    if err != nil {
        fmt.Println("Error:", err)
    }

    // http.ListenAndServe(":9008", &handler) 
}