ajax跨域：JQuery + Spring MVC3.0

$.ajax({
url: "http://localhost:8080/sensing/heatmap/get/shop-1001/2014-07-28/2014-07-28",
dataType:'jsonp',
processData: false,
type:'get',
jsonp:'jsoncallback',
//complete :function(){$("#load").hide();},// AJAX请求完成时隐藏loading提示
success: function(msg){// msg为返回的数据，在这里做数据绑定
alert(msg);
alert("x:"+msg.x+"   y:"+msg.y);
alert("value:"+msg.value);
},
error: function(){
}
});

@RequestMapping(value = "/get/shop-{shopId}/{startDate}/{endDate}")
@ResponseBody
public Object getHeatmap(@PathVariable long shopId, @PathVariable String startDate, @PathVariable String endDate, HttpServletRequest request) {
shopId = getSessionShopId(request, shopId);
Heatmap heatmap = new Heatmap();
Map<String, Object> modelMap = new HashMap<String, Object>();
modelMap.put("x",heatmap.getX());
modelMap.put("y", heatmap.getY());
modelMap.put("value",heatmap.getValue());

String callback = request.getParameter("jsoncallback");
if(callback!=null){//跨域访问
JSONPObject res = new JSONPObject(callback, modelMap);
return res;
}else{//域内访问
return modelMap;
}
}