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 User 服务,/api/shop
转发到到 Shop 服务。Zuul 默认和 Ribbon 结合实现了负载均衡的功能
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.funtl</groupId>
<artifactId>hello-spring-cloud-dependencies</artifactId>
<version>1.0.0-SNAPSHOT</version>
<relativePath>../hello-spring-cloud-dependencies/pom.xml</relativePath>
</parent>
<artifactId>hello-spring-cloud-zuul</artifactId>
<packaging>jar</packaging>
<name>hello-spring-cloud-zuul</name>
<inceptionYear>2018-Now</inceptionYear>
<dependencies>
<!-- Spring Boot Begin -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- Spring Boot End -->
<!-- Spring Cloud Begin -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-zuul</artifactId>
</dependency>
<!-- Spring Cloud End -->
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<mainClass>com.lxq.hello.spring.cloud.zuul.ZuulApplication</mainClass>
</configuration>
</plugin>
</plugins>
</build>
</project>
启动类加上两个注解
@EnableZuulProxy //启动Zuul服务
@EnableEurekaClient //启动eureka客户端(被eureka发现)
package com.lxq.hello.spring.cloud.zuul;
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;
/**
* @Author Lxq
* @Date 2020/3/29 14:42
* @Version 1.0
*/
@EnableEurekaClient
@EnableZuulProxy
@SpringBootApplication
public class ZuulApplication {
public static void main(String[] args) {
SpringApplication.run(ZuulApplication.class, args);
}
}
application.yml
spring:
application:
name: hello-spring-cloud-zuul
server:
port: 8769 #zuul服务的端口
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/ #依然注册到eureka上
zuul:
routes: #路由
api-a:
path: /api/a/** #访问路径一 访问localhost:8769/api/a/hi是访问ribbon
serviceId: hello-spring-cloud-web-admin-ribbon #ribbon注册在eureka的服务名
api-b:
path: /api/b/** #访问路径二 访问localhost:8769/api/a/hi是访问feign
serviceId: hello-spring-cloud-web-admin-feign #feign注册在eureka的服务名
相当于zuul路由网关同一管理所有服务
访问 localhost:8769/api/a/hi 和 localhost:8769/api/b/hi 是否能正常访问说明Zuul配置成功
由于网路的不稳定性会出现网路震荡导致Zuul路由失败 如何解决
使用路由回调
创建一个自定义回调类(名字随便但要有意义) 需要实现 spring cloud 提供的 FallBackProvider类
package com.lxq.hello.spring.cloud.zuul.provider;
import com.fasterxml.jackson.databind.ObjectMapper;
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;
import java.util.HashMap;
import java.util.Map;
/**
* @Author Lxq
* @Date 2020/3/29 14:52
* @Version 1.0
* 路由回调
*/
@Component
public class WebAdminFeignFallbackProvider implements FallbackProvider {
@Override
public String getRoute() {
// ServiceId,如果需要所有调用都支持回退,则 return "*" 或 return null
return "hello-spring-cloud-web-admin-feign";
}
@Override
public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
return new ClientHttpResponse() {
/**
* 网关向 api 服务请求失败了,但是消费者客户端向网关发起的请求是成功的,
* 不应该把 api 的 404,500 等问题抛给客户端
* 网关和 api 服务集群对于客户端来说是黑盒
* @return
* @throws IOException
*/
@Override
public HttpStatus getStatusCode() throws IOException {
return HttpStatus.OK;
}
@Override
public int getRawStatusCode() throws IOException {
return HttpStatus.OK.value();
}
@Override
public String getStatusText() throws IOException {
return HttpStatus.OK.getReasonPhrase();
}
@Override
public void close() {
}
/**
*
* @return 响应内容
* @throws IOException
*/
@Override
public InputStream getBody() throws IOException {
ObjectMapper objectMapper = new ObjectMapper();
Map<String, Object> map = new HashMap<>();
map.put("status", 200);
map.put("message", "无法连接,请检查您的网络");
return new ByteArrayInputStream(objectMapper.writeValueAsString(map).getBytes("UTF-8"));
}
@Override
public HttpHeaders getHeaders() {
HttpHeaders headers = new HttpHeaders();
// 和 getBody 中的内容编码一致
headers.setContentType(MediaType.APPLICATION_JSON_UTF8);
return headers;
}
};
}
}
zuul 还可以有过滤的功能,模拟登陆过滤
package com.lxq.hello.spring.cloud.zuul.filter;
import com.netflix.zuul.ZuulFilter;
import com.netflix.zuul.context.RequestContext;
import com.netflix.zuul.exception.ZuulException;
import org.springframework.stereotype.Component;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
/**
* @Author Lxq
* @Date 2020/3/29 15:01
* @Version 1.0
*/
@Component
public class LoginFilter extends ZuulFilter {
@Override
public String filterType() {
return "pre";
}
@Override
public int filterOrder() {
return 0;
}
@Override
public boolean shouldFilter() {
return true;
}
@Override
public Object run() throws ZuulException {
RequestContext currentContext = RequestContext.getCurrentContext();
HttpServletRequest request = currentContext.getRequest();
String token = request.getParameter("token");
if (token == null){
currentContext.setSendZuulResponse(false);
currentContext.setResponseStatusCode(401);
HttpServletResponse response = currentContext.getResponse();
response.setContentType("text/html;charset=utf-8");
try {
response.getWriter().write("非法请求");
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
}