springcloud中使用zuul网关实现反向代理和zuul过滤器

在之前一篇博客搭建的springcloud聚合项目基础上，https://blog.csdn.net/qq_41890624/article/details/103663817

创建一个maven项目，名称为springcloud-zuul

引入依赖

<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.0.3.RELEASE</version>
	</parent>
	<!-- 管理依赖 -->
	<dependencyManagement>
		<dependencies>
			<dependency>
				<groupId>org.springframework.cloud</groupId>
				<artifactId>spring-cloud-dependencies</artifactId>
				<version>Finchley.RELEASE</version>
				<type>pom</type>
				<scope>import</scope>
			</dependency>
		</dependencies>
	</dependencyManagement>
	<dependencies>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-netflix-zuul</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-config</artifactId>
		</dependency>
		<!-- SpringBoot整合eureka客户端 -->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
		</dependency>
	</dependencies>
	<!-- 注意： 这里必须要添加， 否者各种依赖有问题 -->
	<repositories>
		<repository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/libs-milestone</url>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
		</repository>
	</repositories>

application.yml

###注册 中心
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8100/eureka/
server:
  port: 80
###网关名称
spring:
  application:
    name: service-zuul
### 配置网关反向代理    
zuul:
  routes:
    api-a:
     ### 以 /api-member/访问转发到会员服务
      path: /api-member/**
      ###要转发服务的别名
      serviceId: app-vhukze-member
    api-b:
        ### 以 /api-order/访问转发到订单服务
      path: /api-order/**
      serviceId: app-vhukze-order

创建一个启动类

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;

@SpringBootApplication
@EnableEurekaClient
@EnableZuulProxy
public class ZuulApp {

	public static void main(String[] args) {
		SpringApplication.run(ZuulApp.class, args);
	}
}

创建一个过滤器

import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

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

@Component
public class TokenFilter extends ZuulFilter{

	//编写过滤器拦截业务代码
	public Object run() throws ZuulException {
		// TODO Auto-generated method stub
		
		//案例：拦截所有服务接口，判断服务接口上是否传有UserToken类型参数
		
		RequestContext currentContext = RequestContext.getCurrentContext();
		
		HttpServletRequest request = currentContext.getRequest();
		
		String token = request.getParameter("userToken");
		
		if(StringUtils.isEmpty(token)) {
			//不会继续执行，直接响应给客户端
			currentContext.setSendZuulResponse(false);
			//响应的内容
			currentContext.setResponseBody("userToken is null");
		}
		
		return null;
	}

	//过滤器是否执行，可以添加一些逻辑，当满族条件时执行过滤器
	public boolean shouldFilter() {
		// TODO Auto-generated method stub
		return true;
	}

	//过滤器执行顺序，当一个请求在同一个阶段有过个过滤器时，多个过滤器的执行顺序
	@Override
	public int filterOrder() {
		// TODO Auto-generated method stub
		return 0;
	}

	//过滤器类型 pre是请求前执行
//	pre：在请求被转发之前，执行过滤器
//	**route：**过滤器可以处理实际的请求转发
//	post：在请求被转发之后，执行过滤器
//	error：在请求被转发时发生错误，执行过滤器
	@Override
	public String filterType() {
		// TODO Auto-generated method stub
		return "pre";
	}

}

启动Eureka、订单服务项目、会员服务项目、zuul网关项目

80端口号可以省略的

访问http://localhost/api-order/toMember?name=22

访问http://localhost/api-order/toMember?name=22&userToken=111