网关 Spring Cloud Zuul 跨域问题

雨点打透心脏的1/2处 2023-01-22 04:57 1阅读 0赞

### 文章目录 ###

*   *  corsFilter方式
     *  自定义跨域ZuulFilter

## corsFilter方式 ##

在zuul服务下添加一个corsFilter实现跨域，实现起来方便。代码如下

@Configuration
    public class GateWayCorsConfig { 
       @Bean
        public FilterRegistrationBean corsFilter() { 
            final UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
            final CorsConfiguration config = new CorsConfiguration();
            config.setAllowCredentials(true);
            config.addAllowedOrigin("*");
            config.addAllowedHeader("*");
            config.addAllowedMethod("*");
            //这个请求头在https中会出现,但是有点问题，下面我会说
            //config.addExposedHeader("X-forwared-port, X-forwarded-host"); 
            source.registerCorsConfiguration("/**", config);
            FilterRegistrationBean bean = new FilterRegistrationBean(new CorsFilter(source));
            bean.setOrder(Ordered.HIGHEST_PRECEDENCE); //越小越排前面
            return bean;
        }
    }

## 自定义跨域ZuulFilter ##

因为第一种方式在https下失败后，我尝试了用zuulfilter实现cors的方式

一共需要两个filiter：一个pre, 一个post

Pre-Filter 用来处理预处理OPTIONS请求，当发现是OPTIONS请求的时候，给出跨域响应头，并且不对其进行zuul路由，直接返回成功（200）, 给前端服务允许跨域

@Component
    public class FirstFilter extends ZuulFilter { 
    
        private Logger logger = LoggerFactory.getLogger(FirstFilter.class);
    
        @Override
        public String filterType() { 
            /* pre：可以在请求被路由之前调用 route：在路由请求时候被调用 post：在route和error过滤器之后被调用 error：处理请求时发生错误时被调用 * */
            // 前置过滤器
            return FilterConstants.PRE_TYPE;
        }
    
        @Override
        public int filterOrder() { 
            优先级为0，数字越大，优先级越低
            return 0;
        }
        @Override
        public boolean shouldFilter() { 
            RequestContext ctx = RequestContext.getCurrentContext();
            HttpServletRequest request = ctx.getRequest();
            //只过滤OPTIONS 请求
            if(request.getMethod().equals(RequestMethod.OPTIONS.name())){ 
                return true;
            }
    
            return false;
        }
    
        @Override
        public Object run() { 
            logger.debug("*****************FirstFilter run start*****************");
            RequestContext ctx = RequestContext.getCurrentContext();
            HttpServletResponse response = ctx.getResponse();
            HttpServletRequest request = ctx.getRequest();
            response.setHeader("Access-Control-Allow-Origin",request.getHeader("Origin"));
            response.setHeader("Access-Control-Allow-Credentials","true");
            response.setHeader("Access-Control-Allow-Headers","authorization, content-type");
            response.setHeader("Access-Control-Allow-Methods","POST,GET");
            response.setHeader("Access-Control-Expose-Headers","X-forwared-port, X-forwarded-host");
            response.setHeader("Vary","Origin,Access-Control-Request-Method,Access-Control-Request-Headers");
            //不再路由
            ctx.setSendZuulResponse(false);
            ctx.setResponseStatusCode(200);
            logger.debug("*****************FirstFilter run end*****************");
            return null;
        }
    }

@Component
    public class PostFilter extends ZuulFilter { 
    
        private Logger logger = LoggerFactory.getLogger(PostFilter.class);
    
        @Override
        public String filterType() { 
            /* pre：可以在请求被路由之前调用 route：在路由请求时候被调用 post：在route和error过滤器之后被调用 error：处理请求时发生错误时被调用 * */
            // 前置过滤器
            return FilterConstants.POST_TYPE;
        }
    
        @Override
        public int filterOrder() { 
            优先级为0，数字越大，优先级越低
            return 2;
        }
    
        @Override
        public boolean shouldFilter() { 
            RequestContext ctx = RequestContext.getCurrentContext();
            HttpServletRequest request = ctx.getRequest();
            //过滤各种POST请求
            if (request.getMethod().equals(RequestMethod.OPTIONS.name())) { 
                return false;
            }
            return true;
        }
    
        @Override
        public Object run() { 
            logger.debug("*****************PostFilter run start*****************");
            RequestContext ctx = RequestContext.getCurrentContext();
            HttpServletResponse response = ctx.getResponse();
            HttpServletRequest request = ctx.getRequest();
            response.setHeader("Access-Control-Allow-Origin", request.getHeader("Origin"));
            response.setHeader("Access-Control-Allow-Credentials", "true");
            response.setHeader("Access-Control-Expose-Headers", "X-forwared-port, X-forwarded-host");
            response.setHeader("Vary", "Origin,Access-Control-Request-Method,Access-Control-Request-Headers");
            //允许继续路由
            ctx.setSendZuulResponse(true);
            ctx.setResponseStatusCode(200);
            logger.debug("*****************PostFilter run end*****************");
            return null;
        }
    }