echart柱状图每个柱子标题过长的解决办法

 xAxis: [
          {
            type: 'category',
            data: ['xx\nxxx', 'xx\nxxx', 'xx\nxxx', 'xx\nxxx', 'xx\nxxx', 'xx\nxxx'],//加入换行符\n
            axisTick: {
              show: false
            },
            axisLine: {
              lineStyle: {
                color: '#00407C',
                opacity: 0.7
              }
            },
            axisLabel: {
              fontSize: '10',
              color: '#fff',
              rotate: 40,//对标题进行旋转
              padding: [10, -5, 0, -15]
            }
          }
        ],