230420 CORS Error

Today, I, who mainly used server-side rendering for development with a colleague at the company, did not know much about cors. Therefore, I implemented the project for the first time excluding cors settings, but a colleague asked me to handle cors errors, and I did not know much about cors, so I wrote this post.

• Error: CORS is an error that occurs because other addresses try to use my home address, preventing resource sharing.

• Solution: There are several ways to set cors in Spring Boot. In the config part where I set security

 //When connecting to the front end, allow CORS.
        http.cors().configurationSource(request -> {

            var cors = new CorsConfiguration();
            // Enter the addresses to allow CORS in the form of a list below.
            cors.setAllowedOrigins(List.of("http://localhost:3000"));
            cors.setAllowedMethods(List.of("*"));
            cors.setAllowedHeaders(List.of("*"));
            cors. setAllowCredentials(true);
            cors.addExposedHeader("Authorization");
            return cors;

Put it in and it worked.

   @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
            .allowedOriginPatterns("*")
            .allowedMethods(HttpMethod.GET.name(), HttpMethod.POST.name(), HttpMethod.PUT.name(),
                HttpMethod.DELETE.name(), HttpMethod.OPTIONS.name())
            .allowedHeaders("*")
            .exposedHeaders("Authorization")
            .allowCredentials(true);
    }