今天主要介紹的是前置攔截器（Pre）和後置攔截器（Post）

1.Pre主要實現的是所有的請求中都必須含有token引數，如果沒有就不讓通過，程式碼如下

package com.lfv.product.filter;

import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;

import io.micrometer.core.instrument.util.StringUtils;

import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_TYPE;

import javax.servlet.http.HttpServletRequest;

import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_DECORATION_FILTER_ORDER;
/**
 * PRE Filter 前置過濾器
 * @author lf
 *
 */
@Component
public class TokenFilter extends ZuulFilter {


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

	@Override
	public int filterOrder() {
		return PRE_DECORATION_FILTER_ORDER - 1;
	}

	@Override
	public String filterType() {
		return PRE_TYPE;
	}
	
	@Override
	public Object run() throws ZuulException {
		RequestContext requestContext = RequestContext.getCurrentContext();
		HttpServletRequest request = requestContext.getRequest();
		String tocken  = request.getParameter("tocken");
		if(StringUtils.isNotBlank(tocken)) {
			System.out.println("tocken="+tocken);
		}else {
			requestContext.setSendZuulResponse(false);//驗證不不通過
			requestContext.setResponseStatusCode(HttpStatus.UNAUTHORIZED.value());//返回401 許可權不足
		}
		return null;
	}

}
 

無tocken的訪問，返回401許可權沒有通過

有token的訪問

 2.Post 後置攔截器程式碼如下

package com.lfv.product.filter;

import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.POST_TYPE;
import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.SEND_RESPONSE_FILTER_ORDER;

import java.util.Date;

import javax.servlet.http.HttpServletResponse;

/**
 * Post後置過濾器，向返回值正新增資料
 * @author lf
 *
 */
@Component
public class AddResponseHeaderFilter extends ZuulFilter {

	@Override
	public Object run() throws ZuulException {
		RequestContext requestContext = RequestContext.getCurrentContext();
		HttpServletResponse response = requestContext.getResponse();
		response.setHeader("Zuul Post Filter response", (new Date())+"");
		return null;
	}

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

	@Override
	public int filterOrder() {
		return SEND_RESPONSE_FILTER_ORDER - 1;
	}

	@Override
	public String filterType() {
		return POST_TYPE;
	}

}
 

 返回的結果如下圖