springboot动态加载Echarts柱状图

 @RequestMapping("/rcbchart")
  @ResponseBody
  private String dwcb(@RequestParam("scrq1") String scrq1,@RequestParam("scrq2") String scrq2,
            @RequestParam("dwmc") String dwmc) throws ParseException {
    List category = new ArrayList();   //存放Echart柱状图的category
    List value = new ArrayList();     //存放Echart柱状图的data
 
    List<ViewNyDwrcb> list = rcbService.findSearchRcb(scrq1,scrq2,dwmc);
    for(ViewNyDwrcb item : list){
      category.add(item.getScrq());
      value.add(item.getRcb());
    }
 
    String categorydata = JSON.toJSONString(category); //将list集合转换为json数组
    String valuedata = JSON.toJSONString(value);
    JSONObject jsonObject = new JSONObject();
    jsonObject.put("categorydata",categorydata);
    jsonObject.put("valuedata",valuedata);
    jsonObject.put("dwmc",dwmc);
 
    String result = JSON.toJSONString(jsonObject);
 
    return result;
  }

<!-- 为ECharts准备一个具备大小（宽高）的Dom -->
<div id="main" style="width: 500px; height:400px;"></div>
<script>
  $("#mybtn").click(function(){
  // 基于准备好的dom，初始化echarts图表
  var main = echarts.init(document.getElementById('main'));
  //显示加载动画
  main.showLoading();
  var scrq1 = document.getElementById('scrq1').value;
  var scrq2 = document.getElementById('scrq2').value;
  var dwmc = document.getElementById('dwmc').value;
  $.ajax({
    type:"POST",
    cache:false,
    url:"/rcbchart",
    data:{"scrq1": scrq1,"scrq2": scrq2,"dwmc": dwmc},
    dataType: "json",
    success:function (result) {
      var valuedata = JSON.parse(result.valuedata);
      var categorydata = JSON.parse(result.categorydata);
      //隐藏加载动画
      main.hideLoading();
      main.setOption({
        //提示框组件
        tooltip: {
          trigger: 'axis',
          axisPointer: {
            type: 'shadow'
          }
        },
        //直角坐标系内绘图网格，left，right，bottom分别是距离容器左侧，右侧和底部的距离
        grid: {
          left: '3%',
          right: '4%',
          bottom: '3%',
          containLabel: true
        },
        //X轴
        xAxis: {
          type: 'value',
          boundaryGap: [0, 0.01]
        },
        //Y轴
        yAxis: {
          type: 'category',
          data: categorydata
        },
        series: [
          {
            name: result.dwmc,
            type: 'bar',
            data: valuedata
          }
        ]
      })
    }
  })
  });
</script>