go_组合接口

main函数入口

package main

import (
	"fmt"
	"learngo/retriever/mock"
	"learngo/retriever/real"
	"time"
)

func main(){
	var r Retriever
	retriever := mock.Retriever{"this is fyf"}
	inspect(r)
	r = &real.Retriever{
		UserAgent:"Mozilla/5.0",
		TimeOut:time.Minute,
	}
	inspect(r)

	//Type assertion
	reaRetriever:=r.(*real.Retriever)
	fmt.Println(reaRetriever.TimeOut)
	//fmt.Println(download(r))
	fmt.Println(session(&retriever))
}
//interface中的函数不用加func
type Retriever interface {
	Get(url string) string
}

type Poster interface {
	Post(url string ,form map[string]string) string
}

const url  = "http://www.imooc.com"
func post(p Poster){
	p.Post(url,map[string]string{
		"name":"fyf",
		"cource":"golang",
	})
}

//组合interface，RetrieverPoster内部装了两个interface
type RetrieverPoster interface {
	Retriever
	Poster
}

func session (r RetrieverPoster) string{
	r.Post(url,map[string]string{
		"contents":"this is another",
	})
	return r.Get(url)
}

func download(r Retriever) string{
	return  r.Get(url)
}

func inspect(r 	Retriever){
	fmt.Printf("%T %v\n",r,r)
	switch v:=r.(type) {
	case *mock.Retriever:
		fmt.Println("Contents",v.Contents)
	case *real.Retriever:
		fmt.Println("UserAgent",v.UserAgent)
	}
}

　　实现了两个接口

package mock

import "fmt"

type Retriever struct {
	Contents string
}

func (r *Retriever) String() string {
	return fmt.Sprintf("Retriever:{Contents=%s}",r.Contents)
}
//接口1
func (r *Retriever) Post(url string, form map[string]string) string {
	r.Contents = form["contents"]
	return "ok"
}

//go语言中实现了Get(url string)，就被认为实现了Retriever接口
//接口2
func (r *Retriever) Get(url string) string {
	return r.Contents
}