/*

 * jsonp必须是get请求

 * 参数:

 *   url：请求地址，

 *   params：请求体，

 *   success：回调函数

 *   funName: 函数名，jsonp返回数据会调用该函数

 */

function jsonp(url, params, success, funName) {

　　// 如果params是json对象，转换成字符串，格式为"name=张三&age=10"

    if(params && typeof params == 'object') {

        var tempArray = [];

        for(var key in params) {

            var value = params[key];

            tempArray.push(key + "=" + value);

        }

        // tempArray ==> [ 'key1=value1', 'key2=value2']

        // params ==> 'key1=value1&key2=value2'

        params = tempArray.join("&");

        //alert("params:" + params); // params:name=张三&age=10

    }

    var script = document.createElement("script");

    if(!funName) {

        // 定义一个随机的函数名

        var funName = 'callback_' + Date.now() + Math.random().toString().substr(2, 5);

    }

    // 函数定义，jsonp返回数据会调用该函数

    window[funName] = function(data) {

        success(data);

        delete window[funName];

        document.body.removeChild(script);

    }

    //script.src = "http://localhost/Demo01/jsonResult?jsonp=funName";

    url = url + "?" + "jsonp=" + funName;

    if(params) {

        url += "&" + params;

    }

    script.src = url;

    document.body.appendChild(script); // 发送跨域请求，服务器返回数据：funName({"name":"李四","age":20})

}

<script type="text/javascript">

    window.onload = function() {

        var btn = document.getElementById("btn");

        btn.onclick = function() {

            jsonp("http://localhost/Demo01/jsonResult", null, function(data) {

                var fontEle = document.getElementById("font");

                fontEle.innerHTML = data.name + "-" + data.age;

            }, "fun1");

        };

    };

</script>

<input type="button" id="btn" value="点击发送Ajax请求"/>

<h1><font color="red" id="font"></font></h1>

@Controller

public class JsonResultController {

    @RequestMapping("/jsonResult")

    @ResponseBody

    public String fun1(String jsonp) {

        if(jsonp.length() > 0) { // jsonp请求

            return jsonp + "(" + "{\"name\":\"李四\",\"age\":20}" + ")";

        } else {

            return "{\"name\":\"李四\",\"age\":20}";

        }

    }

}