axios向后台springboot服务器发送请求时出现的错误

this.$axios.post("http://localhost:8080/changeExamStatus?billID="+this.tableData[index].billID).then((response)=>{
            if(response.data.code==1){
              alert("第" + (index + 1) + "项申请单审核成功");
            }
          })