After separation of the front and rear end, to solve cross-domain problems

https://blog.csdn.net/zhaokejin521/article/details/81007884

note:

 If you are using Spring Security, make sure you have enabled CORS in Spring Security

@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.cors().and()...
    }
}