package com.ralab.ralabzuul.filter;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.netflix.zuul.filters.support.FilterConstants;
import org.springframework.stereotype.Component;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Component
public class MyPreFilter extends ZuulFilter {

    private static final Logger logger= LoggerFactory.getLogger(MyPreFilter.class);
    @Override
    public String filterType() {
        return FilterConstants.PRE_TYPE;
    }

    @Override
    public int filterOrder() {
        return 0;
    }

    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() throws ZuulException {

        RequestContext requestContext = RequestContext.getCurrentContext();        
        HttpServletRequest request = requestContext.getRequest();        

        //获取请求参数
        String token = request.getParameter("token");

        //校验token是否可以通过
        if (StringUtils.isNotBlank(token) && token.equals("maomao")) {
            requestContext.setSendZuulResponse(true);
            requestContext.setResponseStatusCode(200);
            requestContext.set("code", 1);
        } else {
            requestContext.setSendZuulResponse(false);
            requestContext.setResponseStatusCode(401);
            HttpServletResponse response = requestContext.getResponse();
            response.setHeader("content-type", "text/html;charset=utf-8");
            requestContext.setResponseBody("网关认证失败，停止路由");
            requestContext.set("code", 0);
        }

        return null;
    }
}

package com.ralab.ralabzuul.filter;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;

@Component
public class MyFallbackProvider implements FallbackProvider {


    private final Logger logger = LoggerFactory.getLogger(FallbackProvider.class);

    @Override
    public String getRoute() {
        return "*";
    }

    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        if (cause != null && cause.getCause() != null) {
            String reason = cause.getCause().getMessage();
            logger.info("Excption {}",reason);
        }
        return fallbackResponse();
    }

    public ClientHttpResponse fallbackResponse() {
        return new ClientHttpResponse() {
            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.OK;
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return 200;
            }

            @Override
            public String getStatusText() throws IOException {
                return "OK";
            }

            @Override
            public void close() {

            }

            @Override
            public InputStream getBody() throws IOException {
                return new ByteArrayInputStream("当前服务貌似不可用 The service is unavailable.".getBytes());
            }

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders headers = new HttpHeaders();
                headers.setContentType(MediaType.APPLICATION_JSON);
                return headers;
            }
        };
    }
}