后端跨域配置（用于支持前端地址与后端地址不同）

@Configuration class CrosConfig implements WebMvcConfigurer {     @Override     public void addCorsMappings(CorsRegistry registry) {         registry.addMapping("/**")                 .allowedOriginPatterns("*")                 .allowedMethods("GET", "HEAD", "POST", "PUT", "DELETE", "OPTIONS")                 .allowCredentials(true)                 .maxAge(3600)                 .allowedHeaders("*");     } }