axios拦截器实现原理

先用拦截器实现下面这个案例：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.bootcdn.net/ajax/libs/axios/0.27.2/axios.js"></script>
    <style>
       
    </style>
</head>
<body>
    <script>
        axios.interceptors.request.use(function (config){
            console.log('请求拦截器1 成功')
            return config;
        },function (error){
            console.log('请求拦截器1 失败')
            return Promise.reject(error)
        })
        axios.interceptors.request.use(function (config){
            console.log('请求拦截器2 成功')
            return config;
        },function (error){
            console.log('请求拦截器2 失败')
            return Promise.reject(error)
        })
        axios.interceptors.response.use(function (response){
            console.log('响应拦截器1 成功')
            return response;
        },function (error){
            console.log('响应拦截器1 失败')
            return Promise.reject(error)
        })
        axios.interceptors.response.use(function (response){
            console.log('响应拦截器2 成功')
            return response;
        },function (error){
            console.log('响应拦截器2 失败')
            return Promise.reject(error)
        })
        // 发送请求
        axios({
            method: "GET",
            url:"http://localhost:3000/posts"
        }).then(response => {
            console.log(response)
        }).catch(err => {
            console.log(err)
        })
    </script>
</body>
</html>