1.         function ajax(opt) {
    2.             opt = opt || {};
    3.             opt.method = opt.method.toUpperCase() || 'POST';
    4.             opt.url = opt.url || '';
    5.             opt.async = opt.async || true;
    6.             opt.data = opt.data || null;
    7.             opt.success = opt.success || function() {};
    8.             var xmlHttp = null;
    9.             if (XMLHttpRequest) {
    10.                 xmlHttp = new XMLHttpRequest();
    11.             } else {
    12.                 xmlHttp = new ActiveXObject('Microsoft.XMLHTTP');
    13.             }
    14.             var params = [];
    15.             for (var key in opt.data) {
    16.                 params.push(key + ':' + opt.data[key]);
    17.             }
    18.             var postData = params.join('&');
    19.             console.log(postData);
    20.             if (opt.method.toUpperCase() === 'POST') {
    21.                 xmlHttp.open(opt.method, opt.url, opt.async);
    22.              //设置请求头
    23.                 xmlHttp.setRequestHeader('Accept', 'application/json, text/javascript, */*; q=0.01');
    24.                 xmlHttp.setRequestHeader('Content-Type', 'application/json');
    25.                 xmlHttp.setRequestHeader('Cache-Control', 'private');
    26.                 xmlHttp.send(JSON.stringify(opt.data));
    27.             } else if (opt.method.toUpperCase() === 'GET') {
    28.                 xmlHttp.open(opt.method, opt.url + '?' + postData, opt.async);
    29.                 xmlHttp.send(null);
    30.             }
    31.             xmlHttp.onreadystatechange = function() {
    32.                 if (xmlHttp.readyState == 4 && xmlHttp.status == 200) {
    33.                     opt.success(xmlHttp.responseText);
    34.                 }
    35.             };
    36.         }

    使用

    1.  ajax({
    2.             method: 'post',
    3.             url: 'user-center/app/shop/follow',
    4.             data: {
    5.                 access_token: 12312,
    6.                 shop_id: 123123
    7.             },
    8.             success: function(response) {
    9.                 console.log(response);
    10.             }
    11.  });