apollo更改配置刷新@ConfigurationProperties配置类

前言

apollo配置经常使用的方式是@value，比较便捷，如果只出现在一个类中还行，但是如果多个类中并不是很方便，特别是如果出现配置值变化了之后需要触发相关变动也无法实现，因此就会考虑使用配置类@ConfigurationProperties，它能实现：

• 统一管理一组配置。

• 配置变化的时需要触发相关变动只涉及一个bean。

但是apollo配置变化时不会把@ConfigurationProperties的值进行更新，具体看官方文档，需要配合EnvironmentChangeEvent或RefreshScope使用。

可以大概看看：

package com.ctrip.framework.apollo.use.cases.spring.cloud.zuul;
import com.ctrip.framework.apollo.model.ConfigChangeEvent;
import com.ctrip.framework.apollo.spring.annotation.ApolloConfigChangeListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.context.environment.EnvironmentChangeEvent;
import org.springframework.cloud.netflix.zuul.RoutesRefreshedEvent;
import org.springframework.cloud.netflix.zuul.filters.RouteLocator;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;
@Component
public class ZuulPropertiesRefresher implements ApplicationContextAware {
 private static final Logger logger = LoggerFactory.getLogger(ZuulPropertiesRefresher.class);
 private ApplicationContext applicationContext;
 @Autowired
 private RouteLocator routeLocator;
 @ApolloConfigChangeListener(interestedKeyPrefixes = "zuul.")
 public void onChange(ConfigChangeEvent changeEvent) {
   refreshZuulProperties(changeEvent);
 }
 private void refreshZuulProperties(ConfigChangeEvent changeEvent) {
   logger.info("Refreshing zuul properties!");
   /**
    * rebind configuration beans, e.g. ZuulProperties
    * @see org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder#onApplicationEvent
    */
   this.applicationContext.publishEvent(new EnvironmentChangeEvent(changeEvent.changedKeys()));
   /**
    * refresh routes
    * @see org.springframework.cloud.netflix.zuul.ZuulServerAutoConfiguration.ZuulRefreshListener#onApplicationEvent
    */
   this.applicationContext.publishEvent(new RoutesRefreshedEvent(routeLocator));
   logger.info("Zuul properties refreshed!");
 }
 @Override
 public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
   this.applicationContext = applicationContext;
 }
}

使用@ApolloConfigChangeListener注册了apollo配置变化 * ，内部使用了cloud发布EnvironmentChangeEvent事件进行更新。

/*
* Copyright 2022 Apollo Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package com.apolloconfig.apollo.demo.springboot.refresh;
import com.apolloconfig.apollo.demo.springboot.config.SampleRedisConfig;
import com.ctrip.framework.apollo.core.ConfigConsts;
import com.ctrip.framework.apollo.model.ConfigChangeEvent;
import com.ctrip.framework.apollo.spring.annotation.ApolloConfigChangeListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.cloud.context.scope.refresh.RefreshScope;
import org.springframework.stereotype.Component;
@ConditionalOnProperty("redis.cache.enabled")
@Component
public class SpringBootApolloRefreshConfig {
 private static final Logger logger = LoggerFactory.getLogger(SpringBootApolloRefreshConfig.class);
 private final SampleRedisConfig sampleRedisConfig;
 private final RefreshScope refreshScope;
 public SpringBootApolloRefreshConfig(
     final SampleRedisConfig sampleRedisConfig,
     final RefreshScope refreshScope) {
   this.sampleRedisConfig = sampleRedisConfig;
   this.refreshScope = refreshScope;
 }
 @ApolloConfigChangeListener(value = "${listeners}", interestedKeyPrefixes = {"redis.cache."})
 public void onChange(ConfigChangeEvent changeEvent) {
   logger.info("before refresh {}", sampleRedisConfig.toString());
   refreshScope.refresh("sampleRedisConfig");
   logger.info("after refresh {}", sampleRedisConfig);
 }
}

/*
* Copyright 2022 Apollo Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package com.apolloconfig.apollo.demo.springboot.config;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import java.util.List;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.stereotype.Component;
/**
* You may set up data like the following in Apollo: <br /><br /> Properties Sample:
* application.properties
* <pre>
* redis.cache.enabled = true
* redis.cache.expireSeconds = 100
* redis.cache.clusterNodes = 1,2
* redis.cache.commandTimeout = 50
* redis.cache.someMap.key1 = a
* redis.cache.someMap.key2 = b
* redis.cache.someList[0] = c
* redis.cache.someList[1] = d
* </pre>
*
* Yaml Sample: application.yaml
* <pre>
* redis:
*   cache:
*     enabled: true
*     expireSeconds: 100
*     clusterNodes: 1,2
*     commandTimeout: 50
*     someMap:
*       key1: a
*       key2: b
*     someList:
*     - c
*     - d
* </pre>
*
* To make <code>@ConditionalOnProperty</code> work properly, <code>apollo.bootstrap.enabled</code>
* should be set to true and <code>redis.cache.enabled</code> should also be set to true. Check
* 'src/main/resources/application.yml' for more information.
*
*/
@ConditionalOnProperty("redis.cache.enabled")
@ConfigurationProperties(prefix = "redis.cache")
@Component("sampleRedisConfig")
@RefreshScope
public class SampleRedisConfig implements InitializingBean {
 private static final Logger logger = LoggerFactory.getLogger(SampleRedisConfig.class);
 private int expireSeconds;
 private String clusterNodes;
 private int commandTimeout;
 private Map<String, String> someMap = Maps.newLinkedHashMap();
 private List<String> someList = Lists.newLinkedList();
 @Override
 public void afterPropertiesSet() throws Exception {
   logger.info(
       "SampleRedisConfig initialized - expireSeconds: {}, clusterNodes: {}, commandTimeout: {}, someMap: {}, someList: {}",
       expireSeconds, clusterNodes, commandTimeout, someMap, someList);
 }
 public void setExpireSeconds(int expireSeconds) {
   this.expireSeconds = expireSeconds;
 }
 public void setClusterNodes(String clusterNodes) {
   this.clusterNodes = clusterNodes;
 }
 public void setCommandTimeout(int commandTimeout) {
   this.commandTimeout = commandTimeout;
 }
 public Map<String, String> getSomeMap() {
   return someMap;
 }
 public List<String> getSomeList() {
   return someList;
 }
 @Override
 public String toString() {
   return String.format(
       "[SampleRedisConfig] expireSeconds: ％d, clusterNodes: ％s, commandTimeout: ％d, someMap: ％s, someList: ％s",
       expireSeconds, clusterNodes, commandTimeout, someMap, someList);
 }
}

使用了RefreshScope进行刷新配置(重新create bean)，但是不够高效，最理想的事一个值发生变化只要重新把对应的属性set即可。

那么我们下面尝试下，需要解决问题：

• 确定@ApolloConfigChangeListener.value能不能填*表示匹配所有namespace。

• 根据ConfigChangeEvent找到配置类及对应的成员进行set。

解决@ApolloConfigChangeListener监听所有namespace

@ApolloConfigChangeListener(value = "*")
public void onChange(ConfigChangeEvent changeEvent) {
   log.info("onChange changeEvent:{}", changeEvent);
}

发现并不行。应该可以编程式添加listener

编程式添加listener

找到官方文档：

Config config = ConfigService.getAppConfig();
config.addChangeListener(new ConfigChangeListener() {
 @Override
 public void onChange(ConfigChangeEvent changeEvent) {
   for (String key : changeEvent.changedKeys()) {
     ConfigChange change = changeEvent.getChange(key);
     System.out.println(String.format(
       "Found change - key: ％s, oldValue: ％s, newValue: ％s, changeType: ％s",
       change.getPropertyName(), change.getOldValue(),
       change.getNewValue(), change.getChangeType()));
       }
   }
});

ConfigService.getAppConfig()默认监听applicationnamespace，我们需要只监听项目依赖的的namespace。

获取项目依赖的的namespace

google了一下发现：apollo配置中心之--spring boot如何加载apollo。 可以通过environment获取key为ApolloPropertySources，我们尝试下：

@PostConstruct
public void registerApolloConfigChangeListener() {
   //从env中拿到所有已从Apollo加载的propertySource,获取监听的nameSpace
   CompositePropertySource apolloPropertySources = (CompositePropertySource) configurableEnvironment.getPropertySources().get("ApolloPropertySources");
   if (Objects.isNull(apolloPropertySources)) {
       return;
   }
   Collection<PropertySource<?>> propertySourceList = apolloPropertySources.getPropertySources();
   //注册监听所有加载的nameSpace
   propertySourceList.forEach(propertySource -> {
       ConfigChangeListener configChangeListener = changeEvent -> {
           for (String changedKey : changeEvent.changedKeys()) {
               ConfigChange change = changeEvent.getChange(changedKey);
               System.out.println(String.format(
                       "Found change - key: ％s, oldValue: ％s, newValue: ％s, changeType: ％s",
                       change.getPropertyName(), change.getOldValue(),
                       change.getNewValue(), change.getChangeType()));
           }
       };
       Config config = ConfigService.getConfig(propertySource.getName());
       config.addChangeListener(configChangeListener);
   });
}

寻找根据ConfigChangeEvent找到配置类及对应的成员进行set的方式

google了一下，没找到，但是spring肯定有相关的实现，比如读取yml后对 @ConfigurationProperties属性进行填充，通过这篇文章找到ConfigurationPropertiesBindingPostProcessor是核心处理类：

通过ConfigurationPropertiesBindingPostProcessor#postProcessBeforeInitialization进行赋值，下面我们来看看能不能直接使用它：

package com.onepiece.apollo;
import com.ctrip.framework.apollo.Config;
import com.ctrip.framework.apollo.ConfigChangeListener;
import com.ctrip.framework.apollo.ConfigService;
import com.google.common.collect.Maps;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor;
import org.springframework.context.ApplicationContext;
import org.springframework.core.Ordered;
import org.springframework.core.env.CompositePropertySource;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.PropertySource;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.util.Collection;
import java.util.Comparator;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
@Slf4j
@Component
public class ApolloRefreshConfig implements BeanPostProcessor, Ordered {
   @Resource
   private ConfigurableEnvironment configurableEnvironment;
   private Map<String, String> configPrefixBeanNameMapping;
   @Resource
   private ConfigurationPropertiesBindingPostProcessor configurationPropertiesBindingPostProcessor;
   @Resource
   private ApplicationContext applicationContext;
   /**
    * 注册configChangeListener监听指定的NameSpace,默认的业务配置都在与应用名命名的nameSpace,当然了如果希望监听到更多的自己去拿到配置的nameSpace也可以的
    */
   @PostConstruct
   public void registerApolloConfigChangeListener() {
       //从env中拿到所有已从Apollo加载的propertySource,获取监听的nameSpace
       CompositePropertySource apolloPropertySources = (CompositePropertySource) configurableEnvironment.getPropertySources().get("ApolloPropertySources");
       if (Objects.isNull(apolloPropertySources)) {
           return;
       }
       Collection<PropertySource<?>> propertySourceList = apolloPropertySources.getPropertySources();
       //注册监听所有加载的nameSpace
       propertySourceList.forEach(propertySource -> {
           ConfigChangeListener configChangeListener = changeEvent -> {
               for (String changedKey : changeEvent.changedKeys()) {
                   log.info("apollo changed namespace:{} Key:{} value:{}", changeEvent.getNamespace(), changedKey, changeEvent.getChange(changedKey));
                   String beanName = getBeanName(changedKey);
                   configurationPropertiesBindingPostProcessor.postProcessBeforeInitialization(applicationContext.getBean(beanName), beanName);
               }
           };
           Config config = ConfigService.getConfig(propertySource.getName());
           config.addChangeListener(configChangeListener);
       });
   }
   /**
    * register beanName with ConfigurationProperties#prefix if
    * annotation @ConfigurationProperties and @RefreshScope is existed
    *
    * @param bean
    * @param beanName
    * @return
    * @throws BeansException
    */
   @Override
   public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
       ConfigurationProperties propertiesAnno = bean.getClass().getAnnotation(ConfigurationProperties.class);
       if (propertiesAnno != null) {
           if (configPrefixBeanNameMapping == null) {
               configPrefixBeanNameMapping = Maps.newHashMap();
           }
           String prefix = propertiesAnno.prefix() != null ? propertiesAnno.prefix() : propertiesAnno.value() == null ? null : propertiesAnno.value();
           if (StringUtils.isNotBlank(prefix) && StringUtils.isNotBlank(beanName)) {
               this.configPrefixBeanNameMapping.put(prefix, beanName);
           }
       }
       return bean;
   }
   @Override
   public int getOrder() {
       return 0;
   }
   /**
    * 防止可能出现的匹配到短prefix的情况，例如 key = "a.ab.abc", prefixA = "a", prefixB = "a.ab.abc",匹配到prefixA返回的情况,这里需要得到最匹配
    *
    * @param key
    * @return beanName best match key
    */
   private String getBeanName(String key) {
       if (configPrefixBeanNameMapping != null) {
           Optional<Map.Entry<String, String>> bestMatchEntry = configPrefixBeanNameMapping.entrySet().stream()
                   .filter(entryt -> key.startsWith(entryt.getKey() + "."))
                   .max(Comparator.comparing(Map.Entry<String, String>::getKey));
           return bestMatchEntry.map(Map.Entry::getValue).orElse(null);
       }
       return null;
   }
}

来源：https://juejin.cn/post/7218554163050430521