Springboot应用在启动时通常是通过调用SpringApplication.run() 方法进行，配置的加载要在应用最前面部分进行，即在准备Environment阶段进行。在SpringApplication 中有如下代码
public ConfigurableApplicationContext run(String... args) {
ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);
ConfigurableEnvironment environment = prepareEnvironment(listeners, applicationArguments);
configureIgnoreBeanInfo(environment);
private ConfigurableEnvironment prepareEnvironment(SpringApplicationRunListeners listeners,ApplicationArguments applicationArguments) {
ConfigurableEnvironment environment = getOrCreateEnvironment();
configureEnvironment(environment, applicationArguments.getSourceArgs());
ConfigurationPropertySources.attach(environment);
listeners.environmentPrepared(environment);
return environment;
跟踪以上代码发现，配置信息的加载实际上是在监听者中进行的，即ConfigFileApplicationListener，
public class ConfigFileApplicationListener implements EnvironmentPostProcessor, SmartApplicationListener, Ordered {
* 该监听者对哪些事件感兴趣
@Override
public boolean supportsEventType(Class<? extends ApplicationEvent> eventType) {
return ApplicationEnvironmentPreparedEvent.class.isAssignableFrom(eventType)
|| ApplicationPreparedEvent.class.isAssignableFrom(eventType);
@Override
public void onApplicationEvent(ApplicationEvent event) {
if (event instanceof ApplicationEnvironmentPreparedEvent) {
onApplicationEnvironmentPreparedEvent((ApplicationEnvironmentPreparedEvent) event);
private void onApplicationEnvironmentPreparedEvent(ApplicationEnvironmentPreparedEvent event) {
List<EnvironmentPostProcessor> postProcessors = loadPostProcessors();
postProcessors.add(this);
AnnotationAwareOrderComparator.sort(postProcessors);
for (EnvironmentPostProcessor postProcessor : postProcessors) {
postProcessor.postProcessEnvironment(event.getEnvironment(), event.getSpringApplication());
@Override
public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
addPropertySources(environment, application.getResourceLoader());
+ Add config file property sources to the specified environment.
+ @param environment the environment to add source to
+ @param resourceLoader the resource loader
+ @see #addPostProcessors(ConfigurableApplicationContext)
protected void addPropertySources(ConfigurableEnvironment environment, ResourceLoader resourceLoader) {
RandomValuePropertySource.addToEnvironment(environment);
new Loader(environment, resourceLoader).load();
从代码中可以看出，该监听器在监听事件后，实际调用的 EnvironmentPostProcessor，通过对EnvironmentPostProcessor进行扩展可以对ConfigurableEnvironment进行定制化处理。而ConfigFileApplicationListener是实现了EnvironmentPostProcessor，所以配置文件的加载也就在这个监听器中进行，从上边的代码看到，调用链接到Loader中，Loader是ConfigFileApplicationListener的内部类，实际加载工作都在Loder中进行。
private class Loader {
void load() {
FilteredPropertySource.apply(this.environment, DEFAULT_PROPERTIES, LOAD_FILTERED_PROPERTY,
(defaultProperties) -> {
this.profiles = new LinkedList<>();
this.processedProfiles = new LinkedList<>();
this.activatedProfiles = false;
this.loaded = new LinkedHashMap<>();
initializeProfiles();
while (!this.profiles.isEmpty()) {
Profile profile = this.profiles.poll();
if (isDefaultProfile(profile)) {
addProfileToEnvironment(profile.getName());
load(profile, this::getPositiveProfileFilter,
addToLoaded(MutablePropertySources::addLast, false));
this.processedProfiles.add(profile);
load(null, this::getNegativeProfileFilter, addToLoaded(MutablePropertySources::addFirst, true));
addLoadedPropertySources();
applyActiveProfiles(defaultProperties);
private void load(Profile profile, DocumentFilterFactory filterFactory, DocumentConsumer consumer) {
getSearchLocations().forEach((location) -> {
boolean isDirectory = location.endsWith("/");
Set<String> names = isDirectory ? getSearchNames() : NO_SEARCH_NAMES;
names.forEach((name) -> load(location, name, profile, filterFactory, consumer));
private void load(String location, String name, Profile profile, DocumentFilterFactory filterFactory,DocumentConsumer consumer) {
if (!StringUtils.hasText(name)) {
for (PropertySourceLoader loader : this.propertySourceLoaders) {
if (canLoadFileExtension(loader, location)) {
load(loader, location, profile, filterFactory.getDocumentFilter(profile), consumer);
return;
Set<String> processed = new HashSet<>();
for (PropertySourceLoader loader : this.propertySourceLoaders) {
for (String fileExtension : loader.getFileExtensions()) {
if (processed.add(fileExtension)) {
loadForFileExtension(loader, location + name, "." + fileExtension, profile, filterFactory,
consumer);
private void loadForFileExtension(PropertySourceLoader loader, String prefix, String fileExtension,
Profile profile, DocumentFilterFactory filterFactory, DocumentConsumer consumer) {
DocumentFilter defaultFilter = filterFactory.getDocumentFilter(null);
DocumentFilter profileFilter = filterFactory.getDocumentFilter(profile);
if (profile != null) {
String profileSpecificFile = prefix + "-" + profile + fileExtension;
load(loader, profileSpecificFile, profile, defaultFilter, consumer);
load(loader, profileSpecificFile, profile, profileFilter, consumer);
for (Profile processedProfile : this.processedProfiles) {
if (processedProfile != null) {
String previouslyLoaded = prefix + "-" + processedProfile + fileExtension;
load(loader, previouslyLoaded, profile, profileFilter, consumer);
load(loader, prefix + fileExtension, profile, profileFilter, consumer);
+ 加载文件
private void load(PropertySourceLoader loader, String location, Profile profile, DocumentFilter filter,DocumentConsumer consumer) {
Resource[] resources = getResources(location);
for (Resource resource : resources) {
try {
String name = "applicationConfig: [" + getLocationName(location, resource) + "]";
List<Document> documents = loadDocuments(loader, name, resource);
if (CollectionUtils.isEmpty(documents)) {
continue;
List<Document> loaded = new ArrayList<>();
for (Document document : documents) {
if (filter.match(document)) {
addActiveProfiles(document.getActiveProfiles());
addIncludedProfiles(document.getIncludeProfiles());
loaded.add(document);
Collections.reverse(loaded);
if (!loaded.isEmpty()) {
loaded.forEach((document) -> consumer.accept(profile, document));
catch (Exception ex) {
通过对以上代码分析，我们可以知道配置文件的加载流程
项目启动SpringApplication.run()
--> prepareEnvironment()
-->SpringApplicationRunListeners.environmentPrepared(environment);(发送ApplicationEnvironmentPreparedEvent)
-->ConfigFileApplicationListener.onApplicationEvent()(监听到event)
-->ConfigFileApplicationListener.postProcessEnvironment()
-->Loader.load()
-->Loader.loadForFileExtension()
Springcloud
在以上文档中我们可以知道Springboot的配置文件加载方式，其实Springcloud是对Springboot进行封装，简单点说cloud执行了两次boot的流程。
新增加监听器BootstrapApplicationListener，该监听器的执行优先级比ConfigFileApplicationListener高，所以在cloud应用启动时先执行BootstrapApplicationListener
public class BootstrapApplicationListener implements ApplicationListener<ApplicationEnvironmentPreparedEvent>, Ordered{
@Override
public void onApplicationEvent(ApplicationEnvironmentPreparedEvent event) {
ConfigurableEnvironment environment = event.getEnvironment();
if (!environment.getProperty("spring.cloud.bootstrap.enabled", Boolean.class,
true)) {
return;
if (environment.getPropertySources().contains(BOOTSTRAP_PROPERTY_SOURCE_NAME)) {
return;
ConfigurableApplicationContext context = null;
String configName = environment
.resolvePlaceholders("${spring.cloud.bootstrap.name:bootstrap}");
for (ApplicationContextInitializer<?> initializer : event.getSpringApplication()
.getInitializers()) {
if (initializer instanceof ParentContextApplicationContextInitializer) {
context = findBootstrapContext(
(ParentContextApplicationContextInitializer) initializer,
configName);
if (context == null) {
context = bootstrapServiceContext(environment, event.getSpringApplication(),
configName);
event.getSpringApplication()
.addListeners(new CloseContextOnFailureApplicationListener(context));
apply(context, event.getSpringApplication(), environment);
private ConfigurableApplicationContext bootstrapServiceContext(
ConfigurableEnvironment environment, final SpringApplication application,
String configName) {
StandardEnvironment bootstrapEnvironment = new StandardEnvironment();
MutablePropertySources bootstrapProperties = bootstrapEnvironment
.getPropertySources();
for (PropertySource<?> source : bootstrapProperties) {
bootstrapProperties.remove(source.getName());
String configLocation = environment
.resolvePlaceholders("${spring.cloud.bootstrap.location:}");
String configAdditionalLocation = environment
.resolvePlaceholders("${spring.cloud.bootstrap.additional-location:}");
Map<String, Object> bootstrapMap = new HashMap<>();
bootstrapMap.put("spring.config.name", configName);
bootstrapMap.put("spring.main.web-application-type", "none");
if (StringUtils.hasText(configLocation)) {
bootstrapMap.put("spring.config.location", configLocation);
if (StringUtils.hasText(configAdditionalLocation)) {
bootstrapMap.put("spring.config.additional-location",
configAdditionalLocation);
bootstrapProperties.addFirst(
new MapPropertySource(BOOTSTRAP_PROPERTY_SOURCE_NAME, bootstrapMap));
for (PropertySource<?> source : environment.getPropertySources()) {
if (source instanceof StubPropertySource) {
continue;
bootstrapProperties.addLast(source);
SpringApplicationBuilder builder = new SpringApplicationBuilder()
.profiles(environment.getActiveProfiles()).bannerMode(Mode.OFF)
.environment(bootstrapEnvironment)
.registerShutdownHook(false).logStartupInfo(false)
.web(WebApplicationType.NONE);
final SpringApplication builderApplication = builder.application();
if (builderApplication.getMainApplicationClass() == null) {
builder.main(application.getMainApplicationClass());
if (environment.getPropertySources().contains("refreshArgs")) {
builderApplication
.setListeners(filterListeners(builderApplication.getListeners()));
builder.sources(BootstrapImportSelectorConfiguration.class);
final ConfigurableApplicationContext context = builder.run();
context.setId("bootstrap");
addAncestorInitializer(application, context);
bootstrapProperties.remove(BOOTSTRAP_PROPERTY_SOURCE_NAME);
mergeDefaultProperties(environment.getPropertySources(), bootstrapProperties);
return context;
+ 向applicationcontext中添加一些信息
private void apply(ConfigurableApplicationContext context,SpringApplication application, ConfigurableEnvironment environment) {
if (application.getAllSources().contains(BootstrapMarkerConfiguration.class)) {
return;
application.addPrimarySources(Arrays.asList(BootstrapMarkerConfiguration.class));
@SuppressWarnings("rawtypes")
Set target = new LinkedHashSet<>(application.getInitializers());
target.addAll(
getOrderedBeansOfType(context, ApplicationContextInitializer.class));
application.setInitializers(target);
addBootstrapDecryptInitializer(application);
由以上代码可以看出，cloud实际上是通过一个优先级较高的Listener来嵌套生成一个bootstrap context，从而能够提前加载一些cloud相关的一些配置，准备cloud的环境，bootstrap context 加载完成后，会继续执行application context的加载，也就是上边的springBoot的加载过程
我们可以得出的调用流程是
项目启动SpringApplication.run()
--> prepareEnvironment()
-->SpringApplicationRunListeners.environmentPrepared(environment);(发送ApplicationEnvironmentPreparedEvent)
-->BootstrapApplicationListener.onApplicationEvent()(监听到event)
-->判断是否正在执行初始化bootstrap context 阶段，若是则跳过该listener，执行后续的listener
-->BootstrapApplicationListener.bootstrapServiceContext()(生成bootstrap context)
-->设置bootstrapEnvironment,spring.config.name,spring.config.location等属性
-->SpringApplicationgBuilder.run()
-->SpringApplication.run()
-->ConfigFileApplicationListener.onApplicationEvent()(监听到event)
-->ConfigFileApplicationListener.postProcessEnvironment()
-->Loader.load()
-->Loader.loadForFileExtension()
复制代码
