SpringCloud之网关服务(gateway)

叁歲伎倆 2022-10-26 15:26 296阅读 0赞

**前言**

![62e3a5346b5d244f3c9a080ba8f6ce6d.png][]

**网关服务在SpringCloud中有很重要的作用。**

可以将服务跟外网进行隔离起到一定的保护作用，同时服务间局域网通信更加快捷。而且在网关中可以做限流、权限校验，使得服务更加专注自身业务。比如说下订单需要登录权限，限流，我们在本篇将介绍如何使用。

搭建网关项目  
![ae004131f578df5c9a3605bd8793f5f8.png][]

注意：需要添加Eureka Discovery，Zuul路由组件。

**1.入口添加@EnableZuulProxy注解**  
![f0b4c492e9a8da7d123147a00b52b0e8.png][]

**2.配置文件**

server:  
port: 9000

\#指定注册中心地址  
eureka:  
client:  
serviceUrl:  
defaultZone: http://localhost:8761/eureka/

\#服务的名称  
spring:  
application:  
name: api-gateway

\#自定义路由映射  
zuul:  
routes:  
order-service: /apigateway/order/\*\*  
product-service: /apigateway/product/\*\*  
\#统一入口为上面的配置，其他入口忽略  
ignored-patterns: /\*-service/\*\*  
\#处理http请求头为空的问题  
sensitive-headers:

**我们启动EurekaServer、productService、OrderService、apigateway，通过访问：**

![fbbd501713cf14a5693171426b65b36c.png][]

![6c51b6da38d30728880e4f7201fbc69d.png][]

统一对外只允许apigateway/product/，apigateway/order/形式访问接口，这样就对外做了一次屏蔽，隐藏了真实的服务api。

网关上做权限校验

权限校验需要通过实现ZuulFilter进行拦截。

package com.ckmike.api\_gateway.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.springframework.http.HttpStatus;  
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;

/\*\*

*  LoginFilter 简要描述
 *  TODO:描述该类职责
 *  
 *  @author ckmike
 *  @version 1.0
 *  @date 18-11-24 下午3:53
 *  @copyright ckmike  
    \*\*/  
    @Component  
    public class LoginFilter extends ZuulFilter \{
    
    public static final String PRE\_TYPE = “pre”;
    
    // 前置过滤器  
    @Override  
    public String filterType() \{  
    return PRE\_TYPE;  
    \}
    
    // 过滤顺序  
    @Override  
    public int filterOrder() \{  
    return 4;  
    \}
    
    @Override  
    public boolean shouldFilter() \{
    
        RequestContext requestContext = RequestContext.getCurrentContext();
         HttpServletRequest request = requestContext.getRequest();
        
         System.out.println("address:" + request.getRemoteAddr());
         System.out.println("uri:" + request.getRequestURI());
         System.out.println("url:" + request.getRequestURL());
         // 这里可以结合ACL进行本地化或者放入到redis
         if ("/apigateway/order/api/v1/order/saveforribbon".equalsIgnoreCase(request.getRequestURI())) {
             return true;
         }
         return false;
    
    \}
    
    @Override  
    public Object run() throws ZuulException \{  
    RequestContext requestContext = RequestContext.getCurrentContext();  
    HttpServletRequest request = requestContext.getRequest();  
    String token = request.getHeader(“token”);  
    if (StringUtils.isBlank(token)) \{  
    token = request.getParameter(“token”);  
    \}  
    if (StringUtils.isBlank(token)) \{  
    requestContext.setSendZuulResponse(false);  
    requestContext.setResponseStatusCode(HttpStatus.UNAUTHORIZED.value());  
    \}  
    return null;  
    \}  
    \}

**启动之后访问对应的接口**  
![a0cf650e18dc0484f3e0e1529d74013f.png][]

到此说明我们以及做好网关的权限校验，通常我们都会结合redis+ACL方式进行，但这里因为简单我直接通过字符串进行校验，有兴趣可自行扩展redis+ACl做。

网关限流

通常系统都有一个承受极限，我们通常可以nginx做一限流，我们也可以通过网关进行限流，网关限流是通过每秒生成令牌作为访问通行标识，这里使用了guava做令牌生成。代码如下：

package com.ckmike.api\_gateway.filter;

import com.google.common.util.concurrent.RateLimiter;  
import com.netflix.zuul.ZuulFilter;  
import com.netflix.zuul.context.RequestContext;  
import com.netflix.zuul.exception.ZuulException;  
import org.springframework.http.HttpStatus;  
import org.springframework.stereotype.Component;

import javax.servlet.http.HttpServletRequest;

/\*\*

*  OrderRateLimiteFilter 简要描述
 *  TODO:描述该类职责
 *  
 *  @author ckmike
 *  @version 1.0
 *  @date 18-11-24 下午5:33
 *  @copyright ckmike  
    \*\*/  
    @Component  
    public class OrderRateLimiteFilter extends ZuulFilter \{
    
    public static final String PRE\_TYPE = “pre”;  
    //每秒钟产生1000个令牌，guava  
    private static final RateLimiter rateLimiter = RateLimiter.create(1000);
    
    @Override  
    public String filterType() \{  
    return PRE\_TYPE;  
    \}
    
    @Override  
    public int filterOrder() \{  
    return -4;  
    \}
    
    @Override  
    public boolean shouldFilter() \{
    
        RequestContext requestContext = RequestContext.getCurrentContext();
         HttpServletRequest request = requestContext.getRequest();
         if ("/apigateway/order/api/v1/order/saveforribbon".equalsIgnoreCase(request.getRequestURI())) {
             return true;
         }
         return false;
    
    \}
    
    @Override  
    public Object run() throws ZuulException \{  
    RequestContext requestContext = RequestContext.getCurrentContext();  
    if (!rateLimiter.tryAcquire()) \{  
    requestContext.setSendZuulResponse(false);  
    requestContext.setResponseStatusCode(HttpStatus.TOO\_MANY\_REQUESTS.value());  
    \}  
    return null;  
    \}  
    \}

我们可以通过jmeter进行压力测试，对/apigateway/order/api/v1/order/saveforribbon接口进行压力测试，这样我们就可以很好的测试上面的内容。

**需要springloud的视频及源码评论区留言哦**

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