一、报错信息

has been blocked by CORS policy: No 'Access-Control-Allow-Origin'
 header is present on the requested resource.

来自一个IP端口的页面（前端项目），要访问另一个IP端口的资源（springboot请求接口），会产生跨域访问。

二、解决方法：增加配置类CorsConfig

@Configuration
public class CorsConfig implements WebMvcConfigurer {

    @Override
    public void addCorsMappings(CorsRegistry registry){
        registry.addMapping("/**")
                .allowedOriginPatterns("*")
                .allowedHeaders(CorsConfiguration.ALL)
                .allowedMethods(CorsConfiguration.ALL)
                .allowCredentials(true)
                .maxAge(3600);
    }
}