SpringCloud 路由网关Zuul

水深无声 2022-05-14 06:54 208阅读 0赞

源码地址：[https://github.com/fymod/easy-spring-cloud/tree/master/06-springcloud-zuul][https_github.com_fymod_easy-spring-cloud_tree_master_06-springcloud-zuul]

Zuul的主要功能是路由转发和过滤器。路由功能是微服务的一部分，比如/api/user转发到到用户服务，/api/address转发到到地址服务。zuul默认和Ribbon结合实现了负载均衡的功能。

### 准备 ###

使用前面涉及到的几个项目  
springcloud-eureka-server：eureka服务端  
springcloud-eureka-client：eureka客户端，供ribbon和feign调用  
springcloud-ribbon：一个微服务，模拟用户服务等  
springcloud-feign：一个微服务，模拟地址微服务等  
依次启动上面4个项目

### 新建项目 ###

新建项目，选择Spring Boot -- Spring Starter Project  
填写基本资料，暂时名称使用springcloud-zuul  
版本选择稳定最新版，勾选Eureka Discovery、Zuul、Web

配置文件

重命名application.yml。

eureka:
      client:
        serviceUrl:
          defaultZone: http://localhost:8761/eureka/
    server:
      port: 8769
    spring:
      application:
        name: service-zuul
    zuul:
      routes:
        api-1:
          path: /api-ribbon/**
          serviceId: service-ribbon
        api-2:
          path: /api-feign/**
          serviceId: service-feign

其中routes指定几条路由，访问path指定路径的时候，会去调用相应serviceId对应的服务。

### Java代码 ###

只需要在SpringcloudZuulApplication添加两个注解即可：  
@EnableZuulProxy  
@EnableEurekaClient

### 运行 ###

网页打开 [http://localhost:8769/api-ribbon/hi?name=aaa][http_localhost_8769_api-ribbon_hi_name_aaa] 验证  
再次打开 [http://localhost:8769/api-feign/hi?name=aaa][http_localhost_8769_api-feign_hi_name_aaa] 验证

### 服务过滤 ###

zuul不仅是路由，还能过滤。比如添加权限和安全控制等。  
以下代码实现只有传递username字段并且名称是fymod才会转发，否则返回相应错误的处理。每个方法上添加了功能说明。

import javax.servlet.http.HttpServletRequest;
    
    import org.springframework.stereotype.Component;
    
    import com.netflix.zuul.ZuulFilter;
    import com.netflix.zuul.context.RequestContext;
    
    @Component
    public class MyFilter extends ZuulFilter {
    
    	@Override
    	public String filterType() {
    //		pre：路由之前
    //		routing：路由之时
    //		post： 路由之后
    //		error：发送错误调用
    		return "pre";
    	}
    
    	/**
    	 * 过滤的顺序
    	 */
    	@Override
    	public int filterOrder() {
    		return 0;
    	}
    
    	/**
    	 * 这里可以写逻辑判断，是否要过滤，true为永远过滤。
    	 */
    	@Override
    	public boolean shouldFilter() {
    		return true;
    	}
    
    	/**
    	 * 过滤器的具体逻辑
    	 * 示例中如果包含用户名并且为fymod，那么允许继续，否则返回错误
    	 */
    	@Override
    	public Object run() {
    		RequestContext ctx = RequestContext.getCurrentContext();
    		HttpServletRequest request = ctx.getRequest();
    		System.out.println(request.getMethod() + "--" + request.getRequestURL().toString());
    		Object username = request.getParameter("username");
    		if (username == null || !"fymod".equals(username.toString())) {
    			ctx.setSendZuulResponse(false);
    			ctx.setResponseStatusCode(401);
    			try {
    				//设置编码格式，否则中文乱码
    				ctx.getResponse().setContentType("text/html;charset=utf-8");
    				ctx.getResponse().getWriter().write("用户名不对");
    			} catch (Exception e) {
    				e.printStackTrace();
    			}
    			return null;
    		}
    		return null;
    	}
    }

### 重新运行 ###

验证以下四个地址返回结果  
[http://localhost:8769/api-ribbon/hi?name=aaa&username=fymod][http_localhost_8769_api-ribbon_hi_name_aaa_username_fymod]  
[http://localhost:8769/api-ribbon/hi?name=aaa&username=test][http_localhost_8769_api-ribbon_hi_name_aaa_username_test]  
[http://localhost:8769/api-feign/hi?name=aaa&username=fymod][http_localhost_8769_api-feign_hi_name_aaa_username_fymod]  
[http://localhost:8769/api-feign/hi?name=aaa&username=test][http_localhost_8769_api-feign_hi_name_aaa_username_test]

[https_github.com_fymod_easy-spring-cloud_tree_master_06-springcloud-zuul]: https://github.com/fymod/easy-spring-cloud/tree/master/06-springcloud-zuul
[http_localhost_8769_api-ribbon_hi_name_aaa]: http://localhost:8769/api-ribbon/hi?name=aaa
[http_localhost_8769_api-feign_hi_name_aaa]: http://localhost:8769/api-feign/hi?name=aaa
[http_localhost_8769_api-ribbon_hi_name_aaa_username_fymod]: http://localhost:8769/api-ribbon/hi?name=aaa&username=fymod
[http_localhost_8769_api-ribbon_hi_name_aaa_username_test]: http://localhost:8769/api-ribbon/hi?name=aaa&username=test
[http_localhost_8769_api-feign_hi_name_aaa_username_fymod]: http://localhost:8769/api-feign/hi?name=aaa&username=fymod
[http_localhost_8769_api-feign_hi_name_aaa_username_test]: http://localhost:8769/api-feign/hi?name=aaa&username=test