文章目录
前言
以前有时遇到找不到相关配置，于是想知道当前服务读取到哪些配置。从源码分析一下。
本文spring boot版本为：2.3.7.RELEASE
结论
1. 什么时候读取完配置文件
main函数从SpringApplication.run方法进入，执行完prepareEnvironment就获取到了本地的配置文件
SpringApplication.java
SpringApplication.run
->ConfigurableEnvironment environment = prepareEnvironment(listeners, applicationArguments);
->listeners.environmentPrepared(environment);
执行完listeners.environmentPrepared(environment);后就可以到
environment.propertySources.propertySourceList的结尾找对应的环境信息
2. 配置文件的读取顺序
1. 目录读取顺序
- jar包所在目录下的config目录 file:./config/
- jar包所在目录下的config目录下的第二层目录 file:./config/*/
- jar包所在目录 file:./
- jar包内classes/config的目录（对应项目中的resources/config目录） classpath:/config/
- jar包内classess的目录（对应项目中的resources目录） classpath:/
2. 文件类型读取顺序
- .properties
- .xml
- .yml
- .yaml
3. 文件名读取顺序
一般项目只会选择一种文件类型作为配置文件，如yml，但配置spring.profiles.active后，会按照配置的名称顺序进行读取。
如在application.yml配置 spring.profiles.active: minio
则读取的文件顺序为：
- application.yml
- application-minio.(properties/xml/yml/yaml)
3. 配置打印类
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import javax.annotation.PostConstruct;
import org.springframework.boot.env.OriginTrackedMapPropertySource;
import org.springframework.context.EnvironmentAware;
import org.springframework.core.env.AbstractEnvironment;
import org.springframework.core.env.Environment;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertySource;
import org.springframework.stereotype.Component;
import lombok.extern.slf4j.Slf4j;
/**
* <p> Description:打印配置文件信息</p>
* <p> CreationTime: 2022/10/31 19:03
*
* @author dreambyday
* @since 1.0
*/
@Slf4j
@Component
public class ConfigFileLog implements EnvironmentAware {
private final List<PropertySource<?>> allPropertySource = new ArrayList<>();
@Override
public void setEnvironment(Environment environment) {
if (!allPropertySource.isEmpty()) {
return ;
}
if (environment instanceof AbstractEnvironment) {
MutablePropertySources propertySources = ((AbstractEnvironment) environment).getPropertySources();
for (PropertySource<?> propertySource : propertySources) {
if (propertySource instanceof OriginTrackedMapPropertySource) {
allPropertySource.add(propertySource);
}
}
}
}
@PostConstruct
private void show() {
for (PropertySource<?> propertySource : allPropertySource) {
log.info("--------------打印配置文件------------{}", propertySource.getName());
Object source = propertySource.getSource();
if (source instanceof Map) {
for (Map.Entry<?, ?> entry : ((Map<?, ?>) source).entrySet()) {
log.info(entry.getKey() + ":" + entry.getValue());
}
}
log.info("--------------完成------------------");
}
}
}
源码分析
以配置文件为resource/application.yml 和 resource/application-minio.yml为例
SpringApplication.java
public ConfigurableApplicationContext run(String... args) {
StopWatch stopWatch = new StopWatch();
stopWatch.start();
ConfigurableApplicationContext context = null;
Collection<SpringBootExceptionReporter> exceptionReporters = new ArrayList<>();
configureHeadlessProperty();
SpringApplicationRunListeners listeners = getRunListeners(args);
listeners.starting();
try {
ApplicationArguments applicationArguments = new DefaultApplicationArguments(args);
// 这一步获取到配置文件中的配置
ConfigurableEnvironment environment = prepareEnvironment(listeners, applicationArguments);
configureIgnoreBeanInfo(environment);
Banner printedBanner = printBanner(environment);
context = createApplicationContext();
exceptionReporters = getSpringFactoriesInstances(SpringBootExceptionReporter.class,
new Class[] { ConfigurableApplicationContext.class }, context);
prepareContext(context, environment, listeners, applicationArguments, printedBanner);
refreshContext(context);
afterRefresh(context, applicationArguments);
stopWatch.stop();
if (this.logStartupInfo) {
new StartupInfoLogger(this.mainApplicationClass).logStarted(getApplicationLog(), stopWatch);
}
listeners.started(context);
callRunners(context, applicationArguments);
}
catch (Throwable ex) {
handleRunFailure(context, ex, exceptionReporters, listeners);
throw new IllegalStateException(ex);
}
try {
listeners.running(context);
}
catch (Throwable ex) {
handleRunFailure(context, ex, exceptionReporters, null);
throw new IllegalStateException(ex);
}
return context;
}
private ConfigurableEnvironment prepareEnvironment(SpringApplicationRunListeners listeners,
ApplicationArguments applicationArguments) {
// Create and configure the environment
ConfigurableEnvironment environment = getOrCreateEnvironment();
configureEnvironment(environment, applicationArguments.getSourceArgs());
ConfigurationPropertySources.attach(environment);
// 在这里读取配置文件。listeners的类型为EventPublishingRunListener
listeners.environmentPrepared(environment);
bindToSpringApplication(environment);
if (!this.isCustomEnvironment) {
environment = new EnvironmentConverter(getClassLoader()).convertEnvironmentIfNecessary(environment,
deduceEnvironmentClass());
}
ConfigurationPropertySources.attach(environment);
return environment;
}
EventPublishingRunListener.java
@Override
public void environmentPrepared(ConfigurableEnvironment environment) {
this.initialMulticaster
.multicastEvent(new ApplicationEnvironmentPreparedEvent(this.application, this.args, environment));
}
SimpleApplicationEventMulticaster.java
@Override
public void multicastEvent(final ApplicationEvent event, @Nullable ResolvableType eventType) {
ResolvableType type = (eventType != null ? eventType : resolveDefaultEventType(event));
Executor executor = getTaskExecutor();
// ConfigFileApplicationListener 这个是读取配置文件的监听器
// 其他监听器，跟读取配置无关
// AnsiOutputApplicationListener、LoggingApplicationListener、ClasspathLoggingApplicationListener
// BackgroundPreintializer、DelegatingApplicationListener、FileEncodingApplicationListener
for (ApplicationListener<?> listener : getApplicationListeners(event, type)) {
if (executor != null) {
executor.execute(() -> invokeListener(listener, event));
}
else {
// 从这里调用listener
invokeListener(listener, event);
}
}
}
protected void invokeListener(ApplicationListener<?> listener, ApplicationEvent event) {
ErrorHandler errorHandler = getErrorHandler();
if (errorHandler != null) {
try {
doInvokeListener(listener, event);
}
catch (Throwable err) {
errorHandler.handleError(err);
}
}
else {
// 这里进入
doInvokeListener(listener, event);
}
}
ConfigFileApplicationListener.java
@Override
public void onApplicationEvent(ApplicationEvent event) {
if (event instanceof ApplicationEnvironmentPreparedEvent) {
// 这里进入
onApplicationEnvironmentPreparedEvent((ApplicationEnvironmentPreparedEvent) event);
}
if (event instanceof ApplicationPreparedEvent) {
onApplicationPreparedEvent(event);
}
}
private void onApplicationEnvironmentPreparedEvent(ApplicationEnvironmentPreparedEvent event) {
List<EnvironmentPostProcessor> postProcessors = loadPostProcessors();
postProcessors.add(this);
AnnotationAwareOrderComparator.sort(postProcessors);
// 读取文件的后置处理：COnfigFileApplicationListener
for (EnvironmentPostProcessor postProcessor : postProcessors) {
// 进入
postProcessor.postProcessEnvironment(event.getEnvironment(), event.getSpringApplication());
}
}
其他监听器
protected void addPropertySources(ConfigurableEnvironment environment, ResourceLoader resourceLoader) {
RandomValuePropertySource.addToEnvironment(environment);
// load（）方法进入
new Loader(environment, resourceLoader).load();
}
1. 文件名顺序源码
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());
}
// 这里进入。第一次读取默认配置文件application.?,在配置文件中找到spring.profiles.active指定文件，加入profiles队列，直到找完。
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;
// 当location为classpath:/ 时从这里进入
names.forEach((name) -> load(location, name, profile, filterFactory, consumer));
});
}
2. 文件目录读取顺序源码getSearchLocations
private Set<String> getSearchLocations() {
Set<String> locations = getSearchLocations(CONFIG_ADDITIONAL_LOCATION_PROPERTY);
if (this.environment.containsProperty(CONFIG_LOCATION_PROPERTY)) {
locations.addAll(getSearchLocations(CONFIG_LOCATION_PROPERTY));
}
else {
locations.addAll(
asResolvedSet(ConfigFileApplicationListener.this.searchLocations, DEFAULT_SEARCH_LOCATIONS));
}
return locations;
}
返回配置文件读取顺序locations
0 = "file:./config/"
1 = "file:./config/*/"
2 = "file:./"
3 = "classpath:/config/"
4 = "classpath:/"
3. 配置文件的读取顺序
先读取PropertiesPropertySourceLoader可以解析的配置文件类型：properties和xml。再读取YamlPropertySourceLoader解析yml和yaml
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;
}
}
throw new IllegalStateException("File extension of config file location '" + location
+ "' is not known to any PropertySourceLoader. If the location is meant to reference "
+ "a directory, it must end in '/'");
}
Set<String> processed = new HashSet<>();
// 两个解析类：PropertiesPropertySourceLoader（properties、xml） YamlPropertySourceLoader （yml、yaml）
for (PropertySourceLoader loader : this.propertySourceLoaders) {
for (String fileExtension : loader.getFileExtensions()) {
if (processed.add(fileExtension)) {
// 当loader为YamlPropertySourceLoader并且fileExtension为yml时 这里进入
loadForFileExtension(loader, location + name, "." + fileExtension, profile, filterFactory,
consumer);
}
}
}
}
后面是再往下的源码了。
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) {
// Try profile-specific file & profile section in profile file (gh-340)
String profileSpecificFile = prefix + "-" + profile + fileExtension;
load(loader, profileSpecificFile, profile, defaultFilter, consumer);
load(loader, profileSpecificFile, profile, profileFilter, consumer);
// Try profile specific sections in files we've already processed
for (Profile processedProfile : this.processedProfiles) {
if (processedProfile != null) {
String previouslyLoaded = prefix + "-" + processedProfile + fileExtension;
load(loader, previouslyLoaded, profile, profileFilter, consumer);
}
}
}
// Also try the profile-specific section (if any) of the normal file
// 这里进入
load(loader, prefix + fileExtension, profile, profileFilter, consumer);
}
// location:classpath:/application.yml
private void load(PropertySourceLoader loader, String location, Profile profile, DocumentFilter filter,
DocumentConsumer consumer) {
Resource[] resources = getResources(location);
for (Resource resource : resources) {
try {
if (resource == null || !resource.exists()) {
if (this.logger.isTraceEnabled()) {
StringBuilder description = getDescription("Skipped missing config ", location, resource,
profile);
this.logger.trace(description);
}
continue;
}
if (!StringUtils.hasText(StringUtils.getFilenameExtension(resource.getFilename()))) {
if (this.logger.isTraceEnabled()) {
StringBuilder description = getDescription("Skipped empty config extension ", location,
resource, profile);
this.logger.trace(description);
}
continue;
}
if (resource.isFile() && isPatternLocation(location) && hasHiddenPathElement(resource)) {
if (this.logger.isTraceEnabled()) {
StringBuilder description = getDescription("Skipped location with hidden path element ",
location, resource, profile);
this.logger.trace(description);
}
continue;
}
String name = "applicationConfig: [" + getLocationName(location, resource) + "]";
// 在这里读取到配置文件中的配置。第一次读取application.yml
List<Document> documents = loadDocuments(loader, name, resource);
if (CollectionUtils.isEmpty(documents)) {
if (this.logger.isTraceEnabled()) {
StringBuilder description = getDescription("Skipped unloaded config ", location, resource,
profile);
this.logger.trace(description);
}
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));
if (this.logger.isDebugEnabled()) {
StringBuilder description = getDescription("Loaded config file ", location, resource,
profile);
this.logger.debug(description);
}
}
}
catch (Exception ex) {
StringBuilder description = getDescription("Failed to load property source from ", location,
resource, profile);
throw new IllegalStateException(description.toString(), ex);
}
}
}