springboot 三种跨域处理方式

springboot 三种跨域处理方式：
1.通过Filter方式实现全局跨域
2.通过Interceptor方式实现全局跨域
3.SpringBoot 自带跨域CrossOrigin注解
Filter方式实现了跨域，那么Interceptor方式跨域就无效；

1.通过Filter方式实现全局跨域

自定义的filter

/**
 *
 * 通过Filter实现全局跨域支持
 */
@Slf4j
@Component
public class CorsConfig implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        log.info("CorsConfig init");
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        log.info("CorsConfig doFilter");
        HttpServletRequest request1 = (HttpServletRequest) request;
        HttpServletResponse response1 = (HttpServletResponse) response;

        if (request1.getHeader("Origin")!=null){
            response1.setHeader("Access-Controller-Allow-Origin"
                    ,request1.getHeader("Origin"));
        }

        response1.setHeader("Access-Control-Allow-Credentials","true");
        response1.setHeader("Access-Control-Allow-Methods","GET, POST, PUT, DELETE, OPTIONS,HEAD");
        response1.setHeader("Access-Control-Max-Age","3600");
        response1.setHeader("Access-Control-Allow-Headers","Content-Type, Accept, X-Requested-With, remember-me");

        chain.doFilter(request,response);
    }

    @Override
    public void destroy() {
        log.info("CorsConfig destroy");
    }
}

还有一种

org.springframework.web.filter 提供的filter跨域类

/**
 * 全局跨域
 * CorsFilter 实现了Filter
 *
 * ：一个http请求，先走filter，到达servlet后才进行拦截器的处理，
 * 所以我们可以把cors放在filter里，就可以优先于权限拦截器执行。
 */
@Slf4j
@Configuration
public class GlobalCorsConfig {
    //允许跨域调用的过滤器
    @Bean
    public CorsFilter corsFilter() {
        log.info("TokenConfig corsFilter");
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", addcorsConfig());
        return new CorsFilter(source);
    }

    private CorsConfiguration addcorsConfig() {
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        List<String> list = new ArrayList<>();
        list.add("*");
        corsConfiguration.setAllowedOrigins(list);
    /*
    // 请求常用的三种配置，*代表允许所有，
    //当时你也可以自定义属性（比如header只能带什么，只能是post方式等等）
    */
       //允许跨越发送cookie
        corsConfiguration.setAllowCredentials(true);
        //允许所有域名进行跨域调用
        corsConfiguration.addAllowedOrigin("*");
        //放行全部原始头信息
        corsConfiguration.addAllowedHeader("*");
        //允许所有请求方法跨域调用
        corsConfiguration.addAllowedMethod("*");
        return corsConfiguration;
    }
}

2.通过Interceptor方式实现全局跨域

/**
 *  
 * 也可以mapping，跨域设置
 */
@Slf4j
@Configuration
public class TokenConfig implements WebMvcConfigurer {

    /**
     * 拦截器实现 跨域支持
     * @param registry
     */
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        log.info("TokenConfig addInterceptors addCorsMappings");
        registry.addMapping("/**")
                .allowedOrigins("*")
                .allowCredentials(true)
                .allowedMethods("GET", "POST", "DELETE", "PUT","OPTIONS","HEAD")
                .allowedHeaders("*")
                .maxAge(3600);
    }

}

第三种方式：SpringBoot 自带跨域CrossOrigin注解

放在RestController的类上或者方法上，还能自定义那些域名可以跨域
@CrossOrigin(origins = "", allowedHeaders = "")