highcharts如何动态获取数据

<script type="text/javascript">
  $(function () {
      $(document).ready(function() {
          Highcharts.setOptions({
              global: {
                  useUTC: false
              }
          });
     
          var chart;
          var url = "<%=root%>/virtual-machine!getCpuLoads.action?ip=${ipAddress}";
              //+$('#hide').val();
          $('#container').highcharts({            
              chart: {
                  type: 'spline',
                  animation: Highcharts.svg, // don't animate in old IE
                  marginRight: 10,
                  events: {
                      load: function() {
                          // set up the updating of the chart each second
                          var series = this.series[0];
                          setInterval(function() {
                            var x = (new Date()).getTime(); // current time           
                               var y;     
                               $.get(url, function(result){
                                  if(!result)return;
             y = parseFloat(result);
          series.addPoint([x, y], true, true);// 为坐标赋值
          });
                          }, 1000);
                      }
                  }
              },
              title: {
                  text: 'CPU使用记录'
              },
              xAxis: {
                  type: 'datetime',
                  tickPixelInterval: 150
              },
              yAxis: {
                        tickInterval: 20,  //自定义刻度 
               max:100,//纵轴的最大值 
               min: 0,//纵轴的最小值 
                  title: {
                      text: 'Value'
                  },
                  plotLines: [{
                      value: 0,
                      width: 1,
                      color: '#808080'
                  }]
              },
              tooltip: {
                  formatter: function() {
                          return '<b>'+ this.series.name +'</b><br/>'+
                          Highcharts.dateFormat('%Y-%m-%d %H:%M:%S', this.x) +'<br/>'+
                          Highcharts.numberFormat(this.y, 2);
                  }
              },
              legend: {
                  enabled: false
              },
              exporting: {
                  enabled: false
              },
              series: [{
                  name: 'CPU使用率',
                  data: (function() {
                      // generate an array of random data
                      var data = [],
                          time = (new Date()).getTime(),
                          i;
     
                      for (i = -19; i <= 0; i++) {
                          data.push({
                              x: time + i * 1000,
                              y: 0
                          });
                      }
                      return data;
                  })()
              }]
          });         
      });
     
  });
 </script>