AXIOS跨域的使用

1、先设置后台servlet页面的参数：

response.setHeader("Access-Control-Allow-Origin", "*");
response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
response.setHeader("Access-Control-Max-Age", "3600");
response.setHeader("Access-Control-Allow-Headers", "Content-Type, Accept");
response.setContentType("text/json; charset=utf-8");

2、AXIOS发起请求需要加入的参数。特别注意Content-Type的值一定要’application/x-www-form-urlencoded’

由于Tomcat对于Content-Type multipart/form-data（文件上传）和application/x-www-form-urlencoded（POST请求）做了“特殊处理”。
//POST文本数据

"Content-Type": "application/x-www-form-urlencoded",

//POST文件

Content-Type multipart/form-data

axios({
   method: "post",
   url: "http://10.0.1.41:8080/KQ/userControl",
   data: {
        userid: that.postUserID,
   },
   headers: {"Content-Type": "application/x-www-form-urlencoded"},
})
 .then(function (response) {
      console.log(response);
})
.catch(function (err) {
      console.log(err);
});