开发中，有的项目需要加入跨域配置，有的不需要，故采用注解加手动注册的方式，使项目可以自由继续跨域配置

自定义注解

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE})
@Import(CorsFilterConfiguration.class)
public @interface EnableCorsFilter {
	String path() default "/**";

	boolean allowCredentials() default true;

	String[] allowedOrigin() default "*";

	String[] allowedHeader() default "*";

	String[] allowedMethod() default "*";

	long maxAge() default 3600L;
}

注册filter

public class CorsFilterConfiguration implements ImportBeanDefinitionRegistrar {

    @Override
    public void registerBeanDefinitions(AnnotationMetadata importingClassMetadata, BeanDefinitionRegistry registry) {
        // 获取注解信息
        AnnotationAttributes annotationAttributes =
                AnnotationAttributes.fromMap(importingClassMetadata.getAnnotationAttributes(EnableCorsFilter.class.getName(), false));
        // 增加跨域配置
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        CorsConfiguration config = new CorsConfiguration();
        config.setAllowCredentials(annotationAttributes.getBoolean("allowCredentials"));
        String[] allowedOrigins = annotationAttributes.getStringArray("allowedOrigin");
        for (String allowedOrigin : allowedOrigins) {
            config.addAllowedOrigin(allowedOrigin);
        }
        String[] allowedHeaders = annotationAttributes.getStringArray("allowedHeader");
        for (String allowedHeader : allowedHeaders) {
            config.addAllowedHeader(allowedHeader);
        }
        String[] allowedMethods = annotationAttributes.getStringArray("allowedMethod");
        for (String allowedMethod : allowedMethods) {
            config.addAllowedMethod(allowedMethod);
        }
        config.setMaxAge(annotationAttributes.getNumber("maxAge"));
        source.registerCorsConfiguration(annotationAttributes.getString("path"), config);
        CorsFilter corsFilter = new CorsFilter(source);
        // 注册
        AbstractBeanDefinition beanDefinition =
                BeanDefinitionBuilder.rootBeanDefinition(FilterRegistrationBean.class).addPropertyValue("filter",corsFilter).addPropertyValue("order", 0).getBeanDefinition();
        registry.registerBeanDefinition("corsFilter", beanDefinition );
    }
}