Spring的跨域的几个方案

public void register(T mapping, Object handler, Method method) {
   // Assert that the handler method is not a suspending one.
   if (KotlinDetector.isKotlinType(method.getDeclaringClass())) {
      Class<?>[] parameterTypes = method.getParameterTypes();
      if ((parameterTypes.length > 0) && "kotlin.coroutines.Continuation".equals(parameterTypes[parameterTypes.length - 1].getName())) {
         throw new IllegalStateException("Unsupported suspending handler method detected: " + method);
      }
   }
   this.readWriteLock.writeLock().lock();
   try {
      HandlerMethod handlerMethod = createHandlerMethod(handler, method);
      validateMethodMapping(handlerMethod, mapping);
      this.mappingLookup.put(mapping, handlerMethod);

      List<String> directUrls = getDirectUrls(mapping);
      for (String url : directUrls) {
         this.urlLookup.add(url, mapping);
      }

      String name = null;
      if (getNamingStrategy() != null) {
         name = getNamingStrategy().getName(handlerMethod, mapping);
         addMappingName(name, handlerMethod);
      }

      CorsConfiguration corsConfig = initCorsConfiguration(handler, method, mapping);
      if (corsConfig != null) {
         this.corsLookup.put(handlerMethod, corsConfig);
      }

      this.registry.put(mapping, new MappingRegistration<>(mapping, handlerMethod, directUrls, name));
   }
   finally {
      this.readWriteLock.writeLock().unlock();
   }
}

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedMethods("*")
                .allowedOrigins("*")
                .allowedHeaders("*")
                .allowCredentials(false)
                .exposedHeaders("")
                .maxAge(3600);
    }
}

@Configuration
public class WebMvcConfig {
    @Bean
    FilterRegistrationBean<CorsFilter> corsFilter() {
        FilterRegistrationBean<CorsFilter> registrationBean = new FilterRegistrationBean<>();
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.setAllowedHeaders(Arrays.asList("*"));
        corsConfiguration.setAllowedMethods(Arrays.asList("*"));
        corsConfiguration.setAllowedOrigins(Arrays.asList("http://localhost:8081"));
        corsConfiguration.setMaxAge(3600L);
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", corsConfiguration);
        registrationBean.setFilter(new CorsFilter(source));
        registrationBean.setOrder(-1);
        return registrationBean;
    }
}

protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
    CorsConfiguration corsConfiguration = this.configSource.getCorsConfiguration(request);
    boolean isValid = this.processor.processRequest(corsConfiguration, request, response);
    if (isValid && !CorsUtils.isPreFlightRequest(request)) {
        filterChain.doFilter(request, response);
    }
}