jsonp获取服务器数据的方式

jsonp获取服务器的数据，有两种  
一，跨域  
二，不跨域  
如果跨域  
js的写法有两种  
1，  
<script type="text/javascript">  
  
  $(function() {  
  $.getJSON('http://localhost:8090/search?jsoncallback=?' ,  
              function(json) {  
                    alert(json);  
                    var html = "";  
                    for (var key in json.data) {  
                        html = html + "<img src='http://localhost:8090/img/99999/o/" + json.data[key].filename + "'><br>";  
                        html = html + "名称:" + json.data[key].filename + "<br>";  
                        html = html + "category:" + json.data[key].category + "<br>";  
                        html = html + "height:" + json.data[key].height + "<br>";  
                        html = html + "width:" + json.data[key].width + "<br>";  
                        html = html + "length:" + json.data[key].length + "<br>";  
                        html = html + "<hr>";  
                    }  
  
                    $('#imageList').html(html);  
                }  
                );  
    });  
  
</script>  
get的ur后面有jsoncallback=?  
这时候，要在服务器端增加如下代码  
hr.getParameter("jsoncallback") +"({jsonp数据的格式})"  
例子  
jQuery1510062266528242707175_1324369820794({"data":[{"category" : "all","height" : "194","_id" : "4ebce7b5523e7e91029f910a","keyword" : "","width" : "259","chunkSize" : "262144","length" : "9082","md5" : "534a94756fc98a6db0483ee702297a82","filename" : "img001_images_029.jpeg","contentType" : "null","uploadDate" : "Fri Nov 11 18:15:33 JST 2011","aliases" : "null"},{"category" : "all","height" : "194","_id" : "4ebce7b5523e7e91029f9108","keyword" : "","width" : "259","chunkSize" : "262144","length" : "10987","md5" : "7b85b894132f78b2b90cd3fef27317a6","filename" : "img001_images_028.jpeg","contentType" : "null","uploadDate" : "Fri Nov 11 18:15:33 JST 2011","aliases" : "null"}]});  
注意，是如下格式jQuery1510062266528242707175_1324369820794({xxxx}),要加个()的哦。  
  
2，get的ur后面有jsoncallback=?的写法可以改为get的ur后面有jsoncallback=getdata  
同时   function(json) 前要加上getdata=  
具体如下  
<script type="text/javascript">  
  
  $(function() {  
  $.getJSON('http://localhost:8090/search?jsoncallback=getdata' ,  
              getdata=function(json) {  
                    alert(json);  
                    var html = "";  
                    for (var key in json.data) {  
                        html = html + "<img src='http://localhost:8090/img/99999/o/" + json.data[key].filename + "'><br>";  
                        html = html + "名称:" + json.data[key].filename + "<br>";  
                        html = html + "category:" + json.data[key].category + "<br>";  
                        html = html + "height:" + json.data[key].height + "<br>";  
                        html = html + "width:" + json.data[key].width + "<br>";  
                        html = html + "length:" + json.data[key].length + "<br>";  
                        html = html + "<hr>";  
                    }  
  
                    $('#imageList').html(html);  
                }  
                );  
    });  
  
</script>  
这个时候，服务器端就不需要加上hr.getParameter("jsoncallback")了，直接返回json格式就行了。  
  
  
具体参见  
http://www.cnblogs.com/5201314/archive/2009/06/23/1509552.html  
http://51mst.iteye.com/blog/1170798  
  
二，如果是不跨域的，  
不需要加上jsoncallback，直接如下就行了，同时服务器返回的格式，就是纯jsonp的格式。  
<script type="text/javascript">  
  $(function() {  
  $.getJSON('http://localhost:8090/search' ,  
              function(json) {  
                    alert(1);  
                    var html = "";  
                    for (var key in json.data) {  
                        html = html + "<img src='http://localhost:8090/img/99999/o/" + json.data[key].filename + "'><br>";  
                        html = html + "名称:" + json.data[key].filename + "<br>";  
                        html = html + "category:" + json.data[key].category + "<br>";  
                        html = html + "height:" + json.data[key].height + "<br>";  
                        html = html + "width:" + json.data[key].width + "<br>";  
                        html = html + "length:" + json.data[key].length + "<br>";  
                        html = html + "<hr>";  
                    }  
  
                    $('#imageList').html(html);  
                }  
                );  
    });  
  
</script>  
服务器返回代码  
{"data":[{"category" : "all","height" : "194","_id" : "4ebce7b5523e7e91029f910a","keyword" : "","width" : "259","chunkSize" : "262144","length" : "9082","md5" : "534a94756fc98a6db0483ee702297a82","filename" : "img001_images_029.jpeg","contentType" : "null","uploadDate" : "Fri Nov 11 18:15:33 JST 2011","aliases" : "null"}]}