//在main.js设置全局的请求次数，请求的间隙

axios.defaults.retry = 4;

axios.defaults.retryDelay = 1000;

axios.interceptors.response.use(undefined, function axiosRetryInterceptor(err) {

    var config = err.config;

    // If config does not exist or the retry option is not set, reject

    if(!config || !config.retry) return Promise.reject(err);

    // Set the variable for keeping track of the retry count

    config.__retryCount = config.__retryCount || 0;

    // Check if we've maxed out the total number of retries

    if(config.__retryCount >= config.retry) {

        // Reject with the error

        return Promise.reject(err);

    }

    // Increase the retry count

    config.__retryCount += 1;

    // Create new promise to handle exponential backoff

    var backoff = new Promise(function(resolve) {

        setTimeout(function() {

            resolve();

        }, config.retryDelay || 1);

    });

    // Return the promise in which recalls axios to retry the request

    return backoff.then(function() {

        return axios(config);

    });

});