使用XMLHttpRequest执行http.post与http.get

0X2 源

var http = (function () {
    var POST = function (url, data, fn) {
        fn = fn || function (ar) { };
        var xhr = new XMLHttpRequest();
        xhr.responseType = 'text';
        xhr.onreadystatechange = function () { if (xhr.readyState === 4) { fn(xhr.responseText); } }
        xhr.open('POST', url, true);
        //console.log(typeof (data));
        var postBody = typeof (data) == 'object' ? JSON.stringify(data) : data;
        xhr.send(postBody);
    };
    var GET = function (url, fn) {
        fn = fn || function (ar) { };
        var xhr = new XMLHttpRequest();
        xhr.onreadystatechange = function () { if (xhr.readyState === 4) { fn(xhr.responseText); } }
        xhr.open('GET', url, false);
        xhr.send(null);
    };
    var JSONP = function (url) {
        var _head = document.head || document.getElementsByTagName('head')[0];
        var hjs = document.createElement('script');
        hjs.setAttribute("src", url);
        hjs.setAttribute("charset", "UTF-8");
        _head.appendChild(hjs);
    };
    var PARSE = function (data) {
        var json = {};
        if (typeof (data) == 'object')
            return data;
        try { json = JSON.parse(data); } catch (ex) { }
        return json;
    };    
    return { "POST": POST, "GET": GET, "PARSE": PARSE, "JSONP": JSONP};
})(JSON);