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;
    }
}