前言
apollo配置經常使用的方式是@value，比較便捷，如果隻出現在一個類中還行，但是如果多個類中并不是很友善，特别是如果出現配置值變化了之後需要觸發相關變動也無法實作，是以就會考慮使用配置類@ConfigurationProperties，它能實作：
- 統一管理一組配置。
- 配置變化的時需要觸發相關變動隻涉及一個bean。
但是apollo配置變化時不會把@ConfigurationProperties的值進行更新，具體看官方文檔，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;
}
}
複制代碼 使用@ApolloConfigChangeListener注冊了apollo配置變化監聽器，内部使用了cloud釋出EnvironmentChangeEvent事件進行更新。
/*
* 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);
}
}
複制代碼 /*
* 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);
}
}
複制代碼 使用了RefreshScope進行重新整理配置(重新create bean)，但是不夠高效，最理想的事一個值發生變化隻要重新把對應的屬性set即可。
那麼我們下面嘗試下，需要解決問題：
- 确定@ApolloConfigChangeListener.value能不能填*表示比對所有namespace。
- 根據ConfigChangeEvent找到配置類及對應的成員進行set。
解決@ApolloConfigChangeListener監聽所有namespace
@ApolloConfigChangeListener(value = "*")
public void onChange(ConfigChangeEvent changeEvent) {
log.info("onChange changeEvent:{}", changeEvent);
}
複制代碼 發現并不行。應該可以程式設計式添加listener
程式設計式添加listener
找到官方文檔：
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()));
}
}
});
複制代碼 ConfigService.getAppConfig()預設監聽applicationnamespace，我們需要隻監聽項目依賴的的namespace。
擷取項目依賴的的namespace
google了一下發現：apollo配置中心之--spring boot如何加載apollo。 可以通過environment擷取key為ApolloPropertySources，我們嘗試下：
@PostConstruct
public void registerApolloConfigChangeListener() {
//從env中拿到所有已從Apollo加載的propertySource,擷取監聽的nameSpace
CompositePropertySource apolloPropertySources = (CompositePropertySource) configurableEnvironment.getPropertySources().get("ApolloPropertySources");
if (Objects.isNull(apolloPropertySources)) {
return;
}
Collection<PropertySource<?>> propertySourceList = apolloPropertySources.getPropertySources();
//注冊監聽所有加載的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);
});
}
複制代碼 尋找根據ConfigChangeEvent找到配置類及對應的成員進行set的方式
google了一下，沒找到，但是spring肯定有相關的實作，比如讀取yml後對 @ConfigurationProperties屬性進行填充，通過這篇文章找到ConfigurationPropertiesBindingPostProcessor是核心處理類：
通過ConfigurationPropertiesBindingPostProcessor#postProcessBeforeInitialization進行指派，下面我們來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;
/**
* 注冊configChangeListener監聽指定的NameSpace,預設的業務配置都在與應用名命名的nameSpace,當然了如果希望監聽到更多的自己去拿到配置的nameSpace也可以的
*/
@PostConstruct
public void registerApolloConfigChangeListener() {
//從env中拿到所有已從Apollo加載的propertySource,擷取監聽的nameSpace
CompositePropertySource apolloPropertySources = (CompositePropertySource) configurableEnvironment.getPropertySources().get("ApolloPropertySources");
if (Objects.isNull(apolloPropertySources)) {
return;
}
Collection<PropertySource<?>> propertySourceList = apolloPropertySources.getPropertySources();
//注冊監聽所有加載的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;
}
/**
* 防止可能出現的比對到短prefix的情況，例如 key = "a.ab.abc", prefixA = "a", prefixB = "a.ab.abc",比對到prefixA傳回的情況,這裡需要得到最比對
*
* @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;
}
}
複制代碼 發現是可以的。
來源：https://juejin.cn/post/7218554163050430521