目录
SpringBoot (2) Environment
SpringBoot版本
SpringBoot 2.1.6
prepareEnvironment
private ConfigurableEnvironment prepareEnvironment(SpringApplicationRunListeners listeners,
ApplicationArguments applicationArguments) {
// Create and configure the environment
ConfigurableEnvironment environment = getOrCreateEnvironment();
configureEnvironment(environment, applicationArguments.getSourceArgs());
listeners.environmentPrepared(environment);
bindToSpringApplication(environment);
if (!this.isCustomEnvironment) {
environment = new EnvironmentConverter(getClassLoader()).convertEnvironmentIfNecessary(environment,
deduceEnvironmentClass());
}
ConfigurationPropertySources.attach(environment);
return environment;
}
getOrCreateEnvironment
在run方法中prepareEnvironment准备创建environment，根据type来决定使用哪种env，如果需要使用web一般来说默认都是StandardServletEnvironment
private ConfigurableEnvironment getOrCreateEnvironment() {
if (this.environment != null) {
return this.environment;
}
switch (this.webApplicationType) {
case SERVLET:
return new StandardServletEnvironment();
case REACTIVE:
return new StandardReactiveWebEnvironment();
default:
return new StandardEnvironment();
}
}
configureEnvironment
当创建了一个environment,首先需要做的就是对这个env做配置
/**
* Template method delegating to
* {@link #configurePropertySources(ConfigurableEnvironment, String[])} and
* {@link #configureProfiles(ConfigurableEnvironment, String[])} in that order.
* Override this method for complete control over Environment customization, or one of
* the above for fine-grained control over property sources or profiles, respectively.
* @param environment this application's environment
* @param args arguments passed to the {@code run} method
* @see #configureProfiles(ConfigurableEnvironment, String[])
* @see #configurePropertySources(ConfigurableEnvironment, String[])
*/
protected void configureEnvironment(ConfigurableEnvironment environment, String[] args) {
if (this.addConversionService) {
ConversionService conversionService = ApplicationConversionService.getSharedInstance();
environment.setConversionService((ConfigurableConversionService) conversionService);
}
configurePropertySources(environment, args);
configureProfiles(environment, args);
}
listeners.environmentPrepared
当environment准备完成，就要发布监听事件
listeners.environmentPrepared(environment);
postProcessEnvironment
ConfigFileApplicationListener接收到env的事件，然后做相应的处理。
@Override
public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
addPropertySources(environment, application.getResourceLoader());
}
addPropertySources
准备加载配置文件property source到指定的environment
/**
* 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();
}
用environment和resourceloader,实例化Loader,来load资源。
赋值environment,placeholdersResolver,resourceLoader,propertySourceLoaders
Loader(ConfigurableEnvironment environment, ResourceLoader resourceLoader) {
this.environment = environment;
this.placeholdersResolver = new PropertySourcesPlaceholdersResolver(this.environment);
this.resourceLoader = (resourceLoader != null) ? resourceLoader : new DefaultResourceLoader();
this.propertySourceLoaders = SpringFactoriesLoader.loadFactories(PropertySourceLoader.class,
getClass().getClassLoader());
}
load
load可以说是hin复杂的一部分，嵌套的太深，但是干的活基本还是load，加载。
public void load() {
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 (profile != null && !profile.isDefaultProfile()) {
addProfileToEnvironment(profile.getName());
}
load(profile, this::getPositiveProfileFilter, addToLoaded(MutablePropertySources::addLast, false));
this.processedProfiles.add(profile);
}
resetEnvironmentProfiles(this.processedProfiles);
load(null, this::getNegativeProfileFilter, addToLoaded(MutablePropertySources::addFirst, true));
addLoadedPropertySources();
}
调用了带3参的load
private void load(Profile profile, DocumentFilterFactory filterFactory, DocumentConsumer consumer) {
getSearchLocations().forEach((location) -> {
boolean isFolder = location.endsWith("/");
Set<String> names = isFolder ? getSearchNames() : NO_SEARCH_NAMES;
names.forEach((name) -> load(location, name, profile, filterFactory, consumer));
});
}
调用了带5参的load
这个load里面会对load做递归call。
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);
}
}
}
}
load的核心基本完成一多半了。
然后开始resetEnvironmentProfiles，为了对env的profile做一次整理
addLoadedPropertySources
最后就是addLoadedPropertySources,把已经封装成为propertySource的资源放到this.environment.getPropertySources()
private void addLoadedPropertySources() {
MutablePropertySources destination = this.environment.getPropertySources();
List<MutablePropertySources> loaded = new ArrayList<>(this.loaded.values());
Collections.reverse(loaded);
String lastAdded = null;
Set<String> added = new HashSet<>();
for (MutablePropertySources sources : loaded) {
for (PropertySource<?> source : sources) {
if (added.add(source.getName())) {
addLoadedPropertySource(destination, lastAdded, source);
lastAdded = source.getName();
}
}
}
}
private void addLoadedPropertySource(MutablePropertySources destination, String lastAdded,
PropertySource<?> source) {
if (lastAdded == null) {
if (destination.contains(DEFAULT_PROPERTIES)) {
destination.addBefore(DEFAULT_PROPERTIES, source);
}
else {
destination.addLast(source);
}
}
else {
destination.addAfter(lastAdded, source);
}
}
小结
environment作为springboot启动的环境准备工作，不可或缺，几乎所有的加载都在这里完成了，
OK，又水了一篇
key word
environment
ConfigFileApplicationListener
EnvironmentPostProcessor
Loader
主目录