apollo更改配置刷新@ConfigurationProperties配置类

目录

• 前言
• 解决@ApolloConfigChangeListener监听所有namespace
• 编程式添加listener
• 获取项目依赖的的namespace
• 寻找根据ConfigChangeEvent找到配置类及对应的成员进行set的方式

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配置变化监听器，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: 

 Properties Sample:
 * application.properties
 * 
 * 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
 * 
 *
 * Yaml Sample: application.yaml
 * 
 * redis:
 *   cache:
 *     enabled: true
 *     expireSeconds: 100
 *     clusterNodes: 1,2
 *     commandTimeout: 50
 *     someMap:
 *       key1: a
 *       key2: b
 *     someList:
 *     - c
 *     - d
 * 
 *
 * To make @ConditionalOnProperty work properly, apollo.bootstrap.enabled
 * should be set to true and redis.cache.enabled 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 someMap = Maps.newLinkedHashMap();
  private List 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 getSomeMap() {
    return someMap;
  }
  public List 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> 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 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> 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> bestMatchEntry = configPrefixBeanNameMapping.entrySet().stream()
                    .filter(entryt -> key.startsWith(entryt.getKey() + "."))
                    .max(Comparator.comparing(Map.Entry::getKey));
            return bestMatchEntry.map(Map.Entry::getValue).orElse(null);
        }
        return null;
    }
}

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