Summary of cases using JSONP

This time I will bring you a summary of the cases of using JSONP. What are the precautions for using JSONP? The following is a practical case, let's take a look.

Both json and JSONP are still very common in development. We will not talk about JSON here.

A well-known problem, Ajax direct request for ordinary files has the problem of cross-domain unauthorized access, regardless of whether you are static pages, dynamic web pages, web services, WCF, as long as it is cross-domain Requests are never allowed, which is why JSONP is used (because when calling js files on a Web page, it is not affected by whether it is cross-domain) (not only that, we also found that all files with the attribute## of "src" # tags all have cross-domain capabilities, such as <script>, <img alt="Summary of cases using JSONP" >, <iframe>)); </script>

Note that ajax and jsonp are essentially different things. The core of ajax is to obtain non-this page content through XmlHttpRequest, while the core of jsonp is to dynamically add the <script> tag to call the js script provided by the server. <p style="max-width:90%"><pre class="brush:php;toolbar:false">private void GetTop10() throws IOException { String jsonCallback = _request.getParameter("jsonCallback"); String id = _request.getParameter("id"); String return_JSONP = top10Setup.ReadTop10(id ); return_JSONP = jsonCallback + "(" + return_JSONP + ");"; System.out.println( return_JSONP ); _response.getWriter().println( return_JSONP ); }Front-end code<p style="text-align: left;"><pre class="brush:php;toolbar:false">function appendListOne() { $.jsonp({ &#39;contentType&#39;: "application/json; charset=utf-8", &#39;url&#39;: AjaxGetUrl, &#39;data&#39;: { dz_type: &#39;GetTop10&#39;, id: 17 }, &#39;dataType&#39;:"jsonp", &#39;callbackParameter&#39;:"jsonCallback", &#39;async&#39;:false, &#39;type&#39;: &#39;post&#39;, &#39;success&#39;: function (data) { console.warn( data ); $("#list1>tbody").empty(); var str=""; for(var key=0;key<data.dblist.length;key++){ var dd=data.dblist[key]; if(key <5){ str+=&#39;<tr><td><b class="ranking">&#39; +(parseInt(key)+1)+ &#39;<span class="name">&#39;+dd.data_name+&#39;&#39; + &#39;<td> <span class="detail">&#39;+dd.data_value+&#39;.&#39;+dd.data_value2+&#39;.&#39;+dd.data_value3+&#39;.&#39;+dd.data_value4 +&#39; &#39;; } } $("#list1>tbody").append(str); } }); } I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the PHP Chinese website! <p>Recommended reading: <p><p style="text-align: left;">How to use json as a parameter in js<a href="http://www.php.cn/js-tutorial-394223.html" target="_blank"><p style="text-align: left;">Summary of the method of converting string to json in JS<a href="http://www.php.cn/js-tutorial-394222.html" target="_blank"> <br/></script>

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