@Configuration
public class AdditionalConfig {

    /**介面中，自動轉換的有：駝峰轉換為下劃線，空值輸出null*/
    @Bean
    public Jackson2ObjectMapperBuilderCustomizer customJackson() {
        return new Jackson2ObjectMapperBuilderCustomizer() {

            @Override
            public void customize(Jackson2ObjectMapperBuilder jacksonObjectMapperBuilder) {
                jacksonObjectMapperBuilder.serializationInclusion(JsonInclude.Include.NON_NULL);
                jacksonObjectMapperBuilder.failOnUnknownProperties(false);
                jacksonObjectMapperBuilder.propertyNamingStrategy(PropertyNamingStrategy.SNAKE_CASE);
            }

        };
    }

    /**允許跨域設定*/
    @Bean
    public CorsFilter corsFilter() {
        final UrlBasedCorsConfigurationSource urlBasedCorsConfigurationSource = new UrlBasedCorsConfigurationSource();
        final CorsConfiguration corsConfig = new CorsConfiguration();
        corsConfig.setAllowCredentials(true);
        corsConfig.addAllowedOrigin("*");
        corsConfig.addAllowedHeader("*");
        corsConfig.addAllowedMethod("OPTIONS");
        corsConfig.addAllowedMethod("HEAD");
        corsConfig.addAllowedMethod("GET");
        corsConfig.addAllowedMethod("PUT");
        corsConfig.addAllowedMethod("POST");
        corsConfig.addAllowedMethod("DELETE");
        corsConfig.addAllowedMethod("PATCH");
        urlBasedCorsConfigurationSource.registerCorsConfiguration("/**", corsConfig);
        return new CorsFilter(urlBasedCorsConfigurationSource);
    }
}