go_接口

package main

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

func main(){
	var r Retriever
	r = mock.Retriever{"this is fyf"}
	r = real.Retriever{}
	fmt.Println(download(r))
}
//interface中的函数不用加func
type Retriever interface {
	Get(url string) string
}

func download(r Retriever) string{
	return  r.Get("http://www.imooc.com")
}

package mock

type Retriever struct {
	Contents string
}

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

package real

import (
	"time"
	"net/http"
	"net/http/httputil"
)

type Retriever struct {
	UserAgent string
	TimeOut time.Duration
}

func (r Retriever) Get(url string) string {
	resp , err :=http.Get(url)
	if err != nil{
		panic(err)
	}
	result,err := httputil.DumpResponse(resp,true)
	resp.Body.Close()
	if err != nil {
		panic(err)
	}
	return string(result)
}