跨域名请求

Access-Control-Allow-Origin 拦截跨源请求

1. 问题

Chrome

Access to XMLHttpRequest at ‘xxxxx’ from origin ‘null’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.

Firefox

已拦截跨源请求：同源策略禁止读取位于 xxxx 的远程资源。（原因：CORS 请求未能成功）

2. 解决

https://developer.mozilla.org/zh-CN/docs/Web/HTTP/CORS/Errors/CORSDidNotSucceed

https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Access_control_CORS

大概就是浏览器不允许使用跨域HTTP请求

协议，端口号，IP地址不同都会引发

• 需要添加’Access-Control-Allow-Origin的请求头信息来允许域名的访问

public String getInfo(HttpServletResponse response){

  //允许所有域名访问
  response.setHeader("Access-Control-Allow-Origin","*");
  
  return "Hello";
}

• SpringBoot中有直接的注解@CrossOrigin

  @RestController
  @RequestMapping("/eduservice/edu-teacher")
  @CrossOrigin
  public class EduTeacherController {}