SpringBoot多环境配置的实现

前言

开发过程中必然使用到的多环境案例，通过简单的案例分析多环境配置的实现过程。

一、案例

1.1主配置文件

spring:profiles:active: prod
server:port: 8080

1.2多环境配置文件

开发环境

blog:domain: http://localhost:8080

测试环境

blog:domain: https://test.lazysnailstudio.com

生产环境

blog:domain: https://lazysnailstudio.com

1.3测试源码

package com.lazy.snail.service;import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;/*** @ClassName BlogInfoService* @Description TODO* @Author lazysnail* @Date 2024/11/15 14:30* @Version 1.0*/
@Service
public class BlogInfoService {@Value("${blog.domain}")private String domain;public String getDomain() {return domain;}
}

package com.lazy.snail.service;import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;/*** @ClassName BlogInfoService* @Description TODO* @Author lazysnail* @Date 2024/11/15 14:30* @Version 1.0*/
@Service
public class BlogInfoService {@Value("${blog.domain}")private String domain;public String getDomain() {return domain;}
}

1.4测试结果

开发环境

测试环境

生产环境

二、配置文件解析过程

2.1SpringBoot启动过程，环境准备阶段

// SpringApplication
public ConfigurableApplicationContext run(String... args) {ConfigurableEnvironment environment = prepareEnvironment(listeners, bootstrapContext, applicationArguments);
}private ConfigurableEnvironment prepareEnvironment(SpringApplicationRunListeners listeners,DefaultBootstrapContext bootstrapContext, ApplicationArguments applicationArguments) {listeners.environmentPrepared(bootstrapContext, environment);
}

2.2事件处理

应用环境准备事件：ApplicationEnvironmentPreparedEvent
事件监听（监听器：EnvironmentPostProcessorApplicationListener）

// EnvironmentPostProcessorApplicationListener
private void onApplicationEnvironmentPreparedEvent(ApplicationEnvironmentPreparedEvent event) {ConfigurableEnvironment environment = event.getEnvironment();SpringApplication application = event.getSpringApplication();for (EnvironmentPostProcessor postProcessor : getEnvironmentPostProcessors(application.getResourceLoader(),event.getBootstrapContext())) {postProcessor.postProcessEnvironment(environment, application);}
}

遍历环境后置处理器

2.3配置数据环境后置处理

核心方法processAndApply

// ConfigDataEnvironmentPostProcessor
public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {postProcessEnvironment(environment, application.getResourceLoader(), application.getAdditionalProfiles());
}void postProcessEnvironment(ConfigurableEnvironment environment, ResourceLoader resourceLoader,Collection<String> additionalProfiles) {try {this.logger.trace("Post-processing environment to add config data");resourceLoader = (resourceLoader != null) ? resourceLoader : new DefaultResourceLoader();getConfigDataEnvironment(environment, resourceLoader, additionalProfiles).processAndApply();}catch (UseLegacyConfigProcessingException ex) {this.logger.debug(LogMessage.format("Switching to legacy config file processing [%s]",ex.getConfigurationProperty()));configureAdditionalProfiles(environment, additionalProfiles);postProcessUsingLegacyApplicationListener(environment, resourceLoader);}
}

processInitial方法解析和加载初始配置文件（如application.yml或application.properties）的内容，封装为contributors对象，解析出来的配置没有立即应用到Spring的Environment中。
processWithoutProfiles在基础的多环境中基本没有额外操作。
withProfiles主要是确定激活的profile
processWithProfiles处理带有profile的配置
applyToEnvironment将配置信息应用到Spring的环境中

// ConfigDataEnvironment
void processAndApply() {ConfigDataImporter importer = new ConfigDataImporter(this.logFactory, this.notFoundAction, this.resolvers,this.loaders);registerBootstrapBinder(this.contributors, null, DENY_INACTIVE_BINDING);ConfigDataEnvironmentContributors contributors = processInitial(this.contributors, importer);ConfigDataActivationContext activationContext = createActivationContext(contributors.getBinder(null, BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE));contributors = processWithoutProfiles(contributors, importer, activationContext);activationContext = withProfiles(contributors, activationContext);contributors = processWithProfiles(contributors, importer, activationContext);applyToEnvironment(contributors, activationContext, importer.getLoadedLocations(),importer.getOptionalLocations());
}private ConfigDataEnvironmentContributors processInitial(ConfigDataEnvironmentContributors contributors,ConfigDataImporter importer) {this.logger.trace("Processing initial config data environment contributors without activation context");contributors = contributors.withProcessedImports(importer, null);registerBootstrapBinder(contributors, null, DENY_INACTIVE_BINDING);return contributors;
}

2.4配置文件路径搜索

找到需要处理的导入，加载相关配置，将结果合并到当前的配置贡献者集合（ConfigDataEnvironmentContributors）中。

// ConfigDataEnvironmentContributors
ConfigDataEnvironmentContributors withProcessedImports(ConfigDataImporter importer,ConfigDataActivationContext activationContext) {// BEFORE_PROFILE_ACTIVATION、AFTER_PROFILE_ACTIVATIONImportPhase importPhase = ImportPhase.get(activationContext);this.logger.trace(LogMessage.format("Processing imports for phase %s. %s", importPhase,(activationContext != null) ? activationContext : "no activation context"));ConfigDataEnvironmentContributors result = this;int processed = 0;while (true) {ConfigDataEnvironmentContributor contributor = getNextToProcess(result, activationContext, importPhase);if (contributor == null) {this.logger.trace(LogMessage.format("Processed imports for of %d contributors", processed));return result;}if (contributor.getKind() == Kind.UNBOUND_IMPORT) {ConfigDataEnvironmentContributor bound = contributor.withBoundProperties(result, activationContext);result = new ConfigDataEnvironmentContributors(this.logger, this.bootstrapContext,result.getRoot().withReplacement(contributor, bound));continue;}ConfigDataLocationResolverContext locationResolverContext = new ContributorConfigDataLocationResolverContext(result, contributor, activationContext);ConfigDataLoaderContext loaderContext = new ContributorDataLoaderContext(this);List<ConfigDataLocation> imports = contributor.getImports();this.logger.trace(LogMessage.format("Processing imports %s", imports));Map<ConfigDataResolutionResult, ConfigData> imported = importer.resolveAndLoad(activationContext,locationResolverContext, loaderContext, imports);this.logger.trace(LogMessage.of(() -> getImportedMessage(imported.keySet())));ConfigDataEnvironmentContributor contributorAndChildren = contributor.withChildren(importPhase,asContributors(imported));result = new ConfigDataEnvironmentContributors(this.logger, this.bootstrapContext,result.getRoot().withReplacement(contributor, contributorAndChildren));processed++;}
}

指定配置文件的搜索路径表达式

optional:file:./;optional:file:./config/;optional:file:./config/*/

classpath:/;optional:classpath:/config/

2.5配置文件解析加载

// ConfigDataImporter
Map<ConfigDataResolutionResult, ConfigData> resolveAndLoad(ConfigDataActivationContext activationContext,ConfigDataLocationResolverContext locationResolverContext, ConfigDataLoaderContext loaderContext,List<ConfigDataLocation> locations) {try {Profiles profiles = (activationContext != null) ? activationContext.getProfiles() : null;List<ConfigDataResolutionResult> resolved = resolve(locationResolverContext, profiles, locations);return load(loaderContext, resolved);} catch (IOException ex) {throw new IllegalStateException("IO error on loading imports from " + locations, ex);}
}

两个解析器

特性	ConfigTreeConfigDataLocationResolver	StandardConfigDataLocationResolver
主要用途	解析配置树格式文件（文件名-文件内容映射）。	解析传统配置文件（`.properties` 和 `.yml`）。
典型场景	容器化环境，如 Kubernetes ConfigMap 或 Secrets。	通常的文件或类路径中的配置文件。
数据来源	挂载的目录结构，例如 `/etc/config`。	本地文件系统或类路径，例如 `application.properties`。
配置导入方式	`spring.config.import=configtree:/path/to/config/`。	默认加载机制或 `spring.config.import=file:/path/to/file/`。

2.5.1解析主配置文件

加载配置文件

// StandardConfigDataLoader
public ConfigData load(ConfigDataLoaderContext context, StandardConfigDataResource resource)throws IOException, ConfigDataNotFoundException {if (resource.isEmptyDirectory()) {return ConfigData.EMPTY;}ConfigDataResourceNotFoundException.throwIfDoesNotExist(resource, resource.getResource());StandardConfigDataReference reference = resource.getReference();Resource originTrackedResource = OriginTrackedResource.of(resource.getResource(),Origin.from(reference.getConfigDataLocation()));String name = String.format("Config resource '%s' via location '%s'", resource,reference.getConfigDataLocation());List<PropertySource<?>> propertySources = reference.getPropertySourceLoader().load(name, originTrackedResource);PropertySourceOptions options = (resource.getProfile() != null) ? PROFILE_SPECIFIC : NON_PROFILE_SPECIFIC;return new ConfigData(propertySources, options);
}

选择对应的加载器加载文件

2.5.2解析激活环境配置

获取激活环境

// ConfigDataEnvironment
private ConfigDataActivationContext withProfiles(ConfigDataEnvironmentContributors contributors,ConfigDataActivationContext activationContext) {this.logger.trace("Deducing profiles from current config data environment contributors");Binder binder = contributors.getBinder(activationContext,(contributor) -> !contributor.hasConfigDataOption(ConfigData.Option.IGNORE_PROFILES),BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE);try {Set<String> additionalProfiles = new LinkedHashSet<>(this.additionalProfiles);additionalProfiles.addAll(getIncludedProfiles(contributors, activationContext));// 构造方法中获取应该激活的环境Profiles profiles = new Profiles(this.environment, binder, additionalProfiles);return activationContext.withProfiles(profiles);} catch (BindException ex) {if (ex.getCause() instanceof InactiveConfigDataAccessException) {throw (InactiveConfigDataAccessException) ex.getCause();}throw ex;}
}

处理激活环境中的配置信息

调用withProcessedImports对application-profiles.yml进行解析加载

2.6环境应用

将所有解析的配置信息应用到Spring的环境中

// ConfigDataEnvironment
private void applyToEnvironment(ConfigDataEnvironmentContributors contributors,ConfigDataActivationContext activationContext, Set<ConfigDataLocation> loadedLocations,Set<ConfigDataLocation> optionalLocations) {checkForInvalidProperties(contributors);checkMandatoryLocations(contributors, activationContext, loadedLocations, optionalLocations);MutablePropertySources propertySources = this.environment.getPropertySources();applyContributor(contributors, activationContext, propertySources);DefaultPropertiesPropertySource.moveToEnd(propertySources);Profiles profiles = activationContext.getProfiles();this.logger.trace(LogMessage.format("Setting default profiles: %s", profiles.getDefault()));this.environment.setDefaultProfiles(StringUtils.toStringArray(profiles.getDefault()));this.logger.trace(LogMessage.format("Setting active profiles: %s", profiles.getActive()));this.environment.setActiveProfiles(StringUtils.toStringArray(profiles.getActive()));this.environmentUpdateListener.onSetProfiles(profiles);
}