springboot 跨域問題解決，解決跨域問題， 配置一下就搞定了

@Configuration
public class CorsConfig {

    @Bean
    public CorsFilter corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.addAllowedOrigin("*");
        corsConfiguration.addAllowedHeader("*");
        corsConfiguration.addAllowedMethod("*");
        source.registerCorsConfiguration("/**", corsConfiguration);
        return new CorsFilter(source);
    }
}

/**
     * 響應前端跨越OPTIONS類型預請求
     *
     * @return 響應http200
     */
    @RequestMapping(value = { "/**" }, method = RequestMethod.OPTIONS)
    public ResponseEntity<?> handleOptions() {
        log.info("OPTIONS預請求響應OK!");
        return ResponseEntity.ok().build();
    }