Spring Cloud 网关服务 zuul  动态路由的实现方法

zuul动态路由

网关服务是流量的唯一入口。不能随便停服务。所以动态路由就显得尤为必要。

数据库动态路由基于事件刷新机制热修改zuul的路由属性。

DiscoveryClientRouteLocator

可以看到DiscoveryClientRouteLocator 是默认的刷新的核心处理类。

//重新加载路由信息方法 protected方法。需要子方法重新方法。
protected LinkedHashMap<String, ZuulRoute> locateRoutes()

//触发刷新的方法 RefreshableRouteLocator 接口
 public void refresh() {
   this.doRefresh();
 }

而这俩个方法都是继承与SimpleRouteLocator 类，并进行了重新操作。其实官方的方法注释说明了。如果需要动态读取加载映射关系。则需要子类重写这俩个方法。

进行具体的实现

首先pom jar包导入 需要连接mysql 数据库  

<dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
  </dependency>

  <!-- jdbc -->
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-jdbc</artifactId>
  </dependency>

路由实体 ZuulRouteEntity

package com.xian.cloud.entity;

import lombok.Data;

import java.io.Serializable;
import java.util.Date;

/**
 * <Description> 路由实体类
 *
 * @author xianliru@100tal.com
 * @version 1.0
 * @createDate 2019/10/30 15:00
 */
@Data
public class ZuulRouteEntity implements Serializable {
 private static final long serialVersionUID = 1L;

 /**
  * router Id
  */
 private Integer id;
 /**
  * 路由路径
  */
 private String path;
 /**
  * 服务名称
  */
 private String serviceId;
 /**
  * url代理
  */
 private String url;
 /**
  * 转发去掉前缀
  */
 private String stripPrefix;
 /**
  * 是否重试
  */
 private String retryable;
 /**
  * 是否启用
  */
 private String enabled;
 /**
  * 敏感请求头
  */
 private String sensitiveheadersList;
 /**
  * 创建时间
  */
 private Date createTime;
 /**
  * 更新时间
  */
 private Date updateTime;
 /**
  * 删除标识（0-正常,1-删除）
  */
 private String delFlag;
}

新建DiscoveryRouteLocator 类 父类 接口 都不变化

package com.xian.cloud.router;


import com.google.common.base.Strings;
import com.google.common.collect.Sets;
import com.xian.cloud.entity.ZuulRoute;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.netflix.zuul.filters.RefreshableRouteLocator;
import org.springframework.cloud.netflix.zuul.filters.SimpleRouteLocator;
import org.springframework.cloud.netflix.zuul.filters.ZuulProperties;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.util.StringUtils;

import java.util.*;

/**
 * <Description>
 *
 * @author xianliru@100tal.com
 * @version 1.0
 * @createDate 2019/10/30 18:57
 */
@Slf4j
public class DiscoveryRouteLocator extends SimpleRouteLocator implements RefreshableRouteLocator {

 private ZuulProperties properties;

 private JdbcTemplate jdbcTemplate;

 public DiscoveryRouteLocator(String servletPath, ZuulProperties properties, JdbcTemplate jdbcTemplate) {
  super(servletPath, properties);
  this.properties = properties;
  this.jdbcTemplate = jdbcTemplate;
  log.info("servletPath:{}",servletPath);
 }

 @Override
 public void refresh() {
  doRefresh();
 }

 @Override
 protected Map<String, ZuulProperties.ZuulRoute> locateRoutes() {
  LinkedHashMap<String, ZuulProperties.ZuulRoute> routesMap = new LinkedHashMap<String, ZuulProperties.ZuulRoute>();
  //从配置文件中加载路由信息
  routesMap.putAll(super.locateRoutes());
  //自定义加载路由信息
  routesMap.putAll(getRouteList());
  //优化一下配置
  LinkedHashMap<String, ZuulProperties.ZuulRoute> values = new LinkedHashMap<>();
  for (Map.Entry<String, ZuulProperties.ZuulRoute> entry : routesMap.entrySet()) {
   String path = entry.getKey();
   // Prepend with slash if not already present.
   if (!path.startsWith("/")) {
    path = "/" + path;
   }
   if (StringUtils.hasText(this.properties.getPrefix())) {
    path = this.properties.getPrefix() + path;
    if (!path.startsWith("/")) {
     path = "/" + path;
    }
   }
   values.put(path, entry.getValue());
  }
  return values;
 }

 /**
  * 从数据库读取zuul路由规则
  * @return
  */
 private LinkedHashMap<String, ZuulProperties.ZuulRoute> getRouteList() {
  LinkedHashMap<String, ZuulProperties.ZuulRoute> zuulRoutes = new LinkedHashMap<>();
  List<ZuulRoute> sysZuulRoutes = jdbcTemplate.query("select * from sys_zuul_route where del_flag = 0", new BeanPropertyRowMapper<>(ZuulRoute.class));

  for (ZuulRoute route: sysZuulRoutes) {

   // 为空跳过
   if (Strings.isNullOrEmpty(route.getPath()) && Strings.isNullOrEmpty(route.getUrl())) {
    continue;
   }

   ZuulProperties.ZuulRoute zuulRoute = new ZuulProperties.ZuulRoute();
   try {
    zuulRoute.setId(route.getServiceId());
    zuulRoute.setPath(route.getPath());
    zuulRoute.setServiceId(route.getServiceId());
    zuulRoute.setRetryable(Objects.equals("0", route.getRetryable()) ? Boolean.FALSE : Boolean.TRUE);
    zuulRoute.setStripPrefix(Objects.equals("0", route.getStripPrefix()) ? Boolean.FALSE : Boolean.TRUE);
    zuulRoute.setUrl(route.getUrl());
    List<String> sensitiveHeadersList = Arrays.asList(route.getSensitiveheadersList().split(","));
    if (sensitiveHeadersList != null) {
     Set<String> sensitiveHeaderSet = Sets.newHashSet();
     sensitiveHeadersList.forEach(sensitiveHeader -> sensitiveHeaderSet.add(sensitiveHeader));
     zuulRoute.setSensitiveHeaders(sensitiveHeaderSet);
     zuulRoute.setCustomSensitiveHeaders(true);
    }
   } catch (Exception e) {
    log.error("数据库加载配置异常", e);
   }
   log.info("自定义的路由配置,path：{}，serviceId:{}", zuulRoute.getPath(), zuulRoute.getServiceId());
   zuulRoutes.put(zuulRoute.getPath(), zuulRoute);

  }
  return zuulRoutes;
 }
}

我们还需要一个事件的生产者 和 消费者 直接图方便 集成到一个类中

package com.xian.cloud.event;

import com.xian.cloud.router.DiscoveryRouteLocator;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.discovery.event.HeartbeatEvent;
import org.springframework.cloud.client.discovery.event.HeartbeatMonitor;
import org.springframework.cloud.context.scope.refresh.RefreshScopeRefreshedEvent;
import org.springframework.cloud.netflix.zuul.RoutesRefreshedEvent;
import org.springframework.cloud.netflix.zuul.web.ZuulHandlerMapping;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.Service;

/**
 * <Description> 路由刷新事件发布，与事件监听者
 *
 * @author xianliru@100tal.com
 * @version 1.0
 * @createDate 2019/10/30 15:27
 */
@Service
public class RefreshRouteService implements ApplicationListener<ApplicationEvent> {

 @Autowired
 private ZuulHandlerMapping zuulHandlerMapping;

 private HeartbeatMonitor heartbeatMonitor = new HeartbeatMonitor();

 @Autowired
 ApplicationEventPublisher publisher;

 @Autowired
 private DiscoveryRouteLocator dynamicRouteLocator;

 /**
  * 动态路由实现 调用refreshRoute() 发布刷新路由事件
  */
 public void refreshRoute() {
  RoutesRefreshedEvent routesRefreshedEvent = new RoutesRefreshedEvent(dynamicRouteLocator);
  publisher.publishEvent(routesRefreshedEvent);
 }

 /**
  * 事件监听者。监控检测事件刷新
  * @param event
  */
 @Override
 public void onApplicationEvent(ApplicationEvent event) {
  if(event instanceof ContextRefreshedEvent || event instanceof RefreshScopeRefreshedEvent || event instanceof RoutesRefreshedEvent){
   //主动手动刷新。上下文刷新，配置属性刷新
   zuulHandlerMapping.setDirty(true);
  }else if(event instanceof HeartbeatEvent){
   //心跳触发，将本地映射关系。关联到远程服务上
   HeartbeatEvent heartbeatEvent = (HeartbeatEvent)event;
   if(heartbeatMonitor.update(heartbeatEvent.getValue())){
    zuulHandlerMapping.setDirty(true);
   }
  }
 }
}

对外提供触发接口

package com.xian.cloud.controller;
import com.xian.cloud.event.RefreshRouteService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
/**
 * <Description> 手动刷新对外接口
 *
 * @author xianliru@100tal.com
 * @version 1.0
 * @createDate 2019/10/30 20:23
 */
@RestController
public class RefreshController {
 @Autowired
 private RefreshRouteService refreshRouteService;
 @GetMapping("/refresh")
 public String refresh() {
  refreshRouteService.refreshRoute();
  return "refresh";
 }
}

数据库表结构

CREATE TABLE `sys_zuul_route` (
 `id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'router Id',
 `path` varchar(255) NOT NULL COMMENT '路由路径',
 `service_id` varchar(255) NOT NULL COMMENT '服务名称',
 `url` varchar(255) DEFAULT NULL COMMENT 'url代理',
 `strip_prefix` char(1) DEFAULT '1' COMMENT '转发去掉前缀',
 `retryable` char(1) DEFAULT '1' COMMENT '是否重试',
 `enabled` char(1) DEFAULT '1' COMMENT '是否启用',
 `sensitiveHeaders_list` varchar(255) DEFAULT NULL COMMENT '敏感请求头',
 `create_time` timestamp NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
 `update_time` timestamp NULL DEFAULT NULL ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间',
 `del_flag` char(1) DEFAULT '0' COMMENT '删除标识（0-正常,1-删除）',
 PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8mb4 ROW_FORMAT=DYNAMIC COMMENT='动态路由配置表'

将配置文件client 消费者服务 路由配置注释掉。设置数据源。从数据库中读取

启动服务打印日志

2019-10-30 20:49:39.946  INFO 63449 --- [TaskScheduler-1] c.xian.cloud.router.DynamicRouteLocator  : 添加数据库自定义的路由配置,path：/client/**，serviceId:cloud-discovery-client
2019-10-30 20:49:40.397  INFO 63449 --- [TaskScheduler-1] c.xian.cloud.router.DynamicRouteLocator  : 添加数据库自定义的路由配置,path：/client/**，serviceId:cloud-discovery-client
postman 请求client 接口 看看是否能转发成功

基于zuul 动态网关路由完成。

总结

以上所述是小编给大家介绍的Spring Cloud 网关服务 zuul  动态路由的实现方法,希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对小牛知识库网站的支持！
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