$.ajax({
            url: url,
            type: 'GET',
            dataType: 'jsonp',
            async:false,
            jsonp: "callback",//传递给请求处理程序或页面的，用以获得jsonp回调函数名的参数名(一般默认为:callback)  
            jsonpCallback: "jsonpcallback",//自定义的jsonp回调函数名称，默认为jQuery自动生成的随机函数名，也可以写"?"，jQuery会自动为你处理数据  
            timeout : 40000,
            success: function(data){
                alert(data[0].name);
            },        
                    
            error: function(XMLHttpRequest, textStatus, errorThrown) {
                 alert(XMLHttpRequest.status);
                 alert(XMLHttpRequest.readyState);
                 alert(textStatus);
            }
        });

String jsonpcallback = request.getParameter("callback");  
        jsonpcallback = jsonpcallback == null ? "" : jsonpcallback;  
        response.setContentType("application/x-javascript");  
        response.setCharacterEncoding("UTF-8");  
        response.setHeader("P3P", "CP=CURa ADMa DEVa PSAo PSDo OUR BUS UNI PUR INT DEM STA PRE COM NAV OTC NOI DSP COR");  
        
        PrintWriter out;
        try {
            out = response.getWriter();
             out.write(jsonpcallback+ "([{ returnFlag:"+bln+",taskid:"+taskid+"}]);");  
              out.flush();  
              out.close(); 
        } catch (IOException e) {
            e.printStackTrace();
        }