springboot 创建环境
SpringApplication 准备环境
private ConfigurableEnvironment prepareEnvironment(SpringApplicationRunListeners listeners,
ApplicationArguments applicationArguments) {
// Create and configure the environment
ConfigurableEnvironment environment = getOrCreateEnvironment(); //默认应用是SERVLET,new StandardServletEnvironment();
configureEnvironment(environment, applicationArguments.getSourceArgs());// enviroment和args进行绑定，如果配置文件不是defaultProperty,这个步骤实际上是个空操作
ConfigurationPropertySources.attach(environment);//给enviroment的source中增加key为configurationProperties的SpringConfigurationPropertySources对象
listeners.environmentPrepared(environment);//主要步骤，查找active的profile
bindToSpringApplication(environment);//与启动类进行绑定
if (!this.isCustomEnvironment) {
environment = new EnvironmentConverter(getClassLoader()).convertEnvironmentIfNecessary(environment,
deduceEnvironmentClass());
}
ConfigurationPropertySources.attach(environment);
return environment;
}
void environmentPrepared(ConfigurableEnvironment environment) {
for (SpringApplicationRunListener listener : this.listeners) {
listener.environmentPrepared(environment);
}
}
EventPublishingRunListener 执行监听事件
private void doInvokeListener(ApplicationListener listener, ApplicationEvent event) {
try {
listener.onApplicationEvent(event);
}catch (ClassCastException ex) {
}
}
ConfigFileApplicationListener 类进行环境加载操作
主要是判断那些profile是active的，并对其配置文件进行解析
1.解析环境
private void onApplicationEnvironmentPreparedEvent(ApplicationEnvironmentPreparedEvent event) {
List<EnvironmentPostProcessor> postProcessors = loadPostProcessors();
postProcessors.add(this);//增加自身实例
AnnotationAwareOrderComparator.sort(postProcessors);
for (EnvironmentPostProcessor postProcessor : postProcessors) {
postProcessor.postProcessEnvironment(event.getEnvironment(), event.getSpringApplication());
}
}
2.loadPostProcessors()方法获取spring.factories中EnvironmentPostProcessor 类配置
# Environment Post Processors
org.springframework.boot.env.EnvironmentPostProcessor=
org.springframework.boot.cloud.CloudFoundryVcapEnvironmentPostProcessor,
org.springframework.boot.env.SpringApplicationJsonEnvironmentPostProcessor,
org.springframework.boot.env.SystemEnvironmentPropertySourceEnvironmentPostProcessor,
org.springframework.boot.reactor.DebugAgentEnvironmentPostProcessor
3.ConfigFileApplicationListener类的postProcessEnvironment方法
加载配置文件，以yml文件进行分析；
protected void addPropertySources(ConfigurableEnvironment environment, ResourceLoader resourceLoader) {
RandomValuePropertySource.addToEnvironment(environment);
new Loader(environment, resourceLoader).load();
}
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());//获取实例类，如下
}
spring.factories中PropertySourceLoader.class 配置的类
yml文件解析的解析类和property文件的解析类
# PropertySource Loaders
org.springframework.boot.env.PropertySourceLoader=
org.springframework.boot.env.PropertiesPropertySourceLoader,
org.springframework.boot.env.YamlPropertySourceLoader
4.加载配置的yml或propertis文件的详细过程
万恶的load方法
以YML文件解析为例，总共涉及到六个load方法，每个方法都处理不同的业务
ConfigFileApplicationListener类的总的加载方法
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);
});
}
根据路径加载配置文件，load()方法
-
getSearchLocations()方法获取配置文件扫描路径。默认是DEFAULT_SEARCH_LOCATIONS。
-
配置文件的名称names 默认是 DEFAULT_NAMES 也即是application。
private static final String DEFAULT_SEARCH_LOCATIONS = "classpath:/,classpath:/config/,file:./,file:./config/";
private static final String DEFAULT_NAMES = "application";
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));//遍历路径查找配置文件
});
}
根据路径，查找yml和properites的配置文件
根据路径 + 文件名称 + 后缀进行配置文件查找
private void load(String location, String name, Profile profile, DocumentFilterFactory filterFactory,
DocumentConsumer consumer) {
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);
}
}
}
}
//PropertiesPropertySourceLoader properties加载器的后缀
public String[] getFileExtensions() {
return new String[] { "properties", "xml" };
}
//YamlPropertySourceLoader yml加载器的后缀
@Override
public String[] getFileExtensions() {
return new String[] { "yml", "yaml" };
}
private void loadForFileExtension(PropertySourceLoader loader, String prefix, String fileExtension,
Profile profile, DocumentFilterFactory filterFactory, DocumentConsumer consumer) {
//省略部分代码。。。。。。。。。。。。。。。。。
load(loader, prefix + fileExtension, profile, profileFilter, consumer); //这里的load方法是加载资源的方法，具体过程如下
}
加载资源，配置数据解析
判断是否为激活的YML配置文件，并且获取YML文件的配置信息
private void load(PropertySourceLoader loader, String location, Profile profile, DocumentFilter filter,
DocumentConsumer consumer) {
try {
Resource resource = this.resourceLoader.getResource(location);
//。。。。。。。。。。。。。。。。。
String name = "applicationConfig: [" + location + "]";
List<Document> documents = loadDocuments(loader, name, resource); //这里是yml文件的加载解析过程，具体如下代码
//。。。。。。。。。。。。。。。。
List<Document> loaded = new ArrayList<>();
for (Document document : documents) {
if (filter.match(document)) {
addActiveProfiles(document.getActiveProfiles());//设置激活yml配置文件
addIncludedProfiles(document.getIncludeProfiles());
loaded.add(document);
}
}
Collections.reverse(loaded);
if (!loaded.isEmpty()) {
loaded.forEach((document) -> consumer.accept(profile, document));
//。。。。。。。。。。。。。。。。。
}
}
catch (Exception ex) {
throw new IllegalStateException("Failed to load property source from location '" + location + "'", ex);
}
}
//获取配置文件解析数据
private List<Document> loadDocuments(PropertySourceLoader loader, String name, Resource resource)
throws IOException {
DocumentsCacheKey cacheKey = new DocumentsCacheKey(loader, resource);
List<Document> documents = this.loadDocumentsCache.get(cacheKey);
if (documents == null) {
List<PropertySource<?>> loaded = loader.load(name, resource);//又是load方法，这里是yml的数据解析过程
documents = asDocuments(loaded);
this.loadDocumentsCache.put(cacheKey, documents);
}
return documents;
}
YamlPropertySourceLoader 加载yml配置文件
这个类是YML文件的加载解析类，下面的类是具体的解析操作
@Override
public List<PropertySource<?>> load(String name, Resource resource) throws IOException {
if (!ClassUtils.isPresent("org.yaml.snakeyaml.Yaml", null)) {
throw new IllegalStateException(
"Attempted to load " + name + " but snakeyaml was not found on the classpath");
}
List<Map<String, Object>> loaded = new OriginTrackedYamlLoader(resource).load();//解析yml配置数据
if (loaded.isEmpty()) {
return Collections.emptyList();
}
List<PropertySource<?>> propertySources = new ArrayList<>(loaded.size());
for (int i = 0; i < loaded.size(); i++) {
String documentNumber = (loaded.size() != 1) ? " (document #" + i + ")" : "";
propertySources.add(new OriginTrackedMapPropertySource(name + documentNumber,
Collections.unmodifiableMap(loaded.get(i)), true));
}
return propertySources;
}
OriginTrackedYamlLoader类
load()方法用于解析数据，将YML配置参数解析成为MAP集合
List<Map<String, Object>> load() {
final List<Map<String, Object>> result = new ArrayList<>();
process((properties, map) -> result.add(getFlattenedMap(map)));
return result;
}
// YamlProcess类的process方法进行yml文件解析
protected void process(MatchCallback callback) {
Yaml yaml = createYaml();
for (Resource resource : this.resources) {
boolean found = process(callback, yaml, resource);
if (this.resolutionMethod == ResolutionMethod.FIRST_FOUND && found) {
return;
}
}
}
以上就是springboot启动时environment的加载过程。