Spring Boot2 源码 run prepareContext方法 （四）

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10、准备应用上下文

	private void prepareContext(ConfigurableApplicationContext context,ConfigurableEnvironment environment, SpringApplicationRunListeners listeners,ApplicationArguments applicationArguments, Banner printedBanner) {//设置环境参数context.setEnvironment(environment);postProcessApplicationContext(context);//所有ApplicationContextInitializer类 初始化applyInitializers(context);//contextPrepared监听事件listeners.contextPrepared(context);if (this.logStartupInfo) {logStartupInfo(context.getParent() == null);logStartupProfileInfo(context);}// 获取beanFactory 为下面注册单例bean做准备ConfigurableListableBeanFactory beanFactory = context.getBeanFactory();beanFactory.registerSingleton("springApplicationArguments", applicationArguments);if (printedBanner != null) {beanFactory.registerSingleton("springBootBanner", printedBanner);}if (beanFactory instanceof DefaultListableBeanFactory) {((DefaultListableBeanFactory) beanFactory).setAllowBeanDefinitionOverriding(this.allowBeanDefinitionOverriding);}// Load the sourcesSet<Object> sources = getAllSources();Assert.notEmpty(sources, "Sources must not be empty");load(context, sources.toArray(new Object[0]));//contextLoaded监听事件listeners.contextLoaded(context);}

public void setEnvironment(ConfigurableEnvironment environment) {// 设置context的environmentsuper.setEnvironment(environment);    // 实例化context的reader属性的environment属性        this.reader.setEnvironment(environment);  // 设置context的scanner属性的environment属性  this.scanner.setEnvironment(environment);    
}

this.beanNameGenerator和this.resourceLoader为空应该是扩展用的

protected void postProcessApplicationContext(ConfigurableApplicationContext context) {if (this.beanNameGenerator != null) {context.getBeanFactory().registerSingleton(AnnotationConfigUtils.CONFIGURATION_BEAN_NAME_GENERATOR,this.beanNameGenerator);}if (this.resourceLoader != null) {if (context instanceof GenericApplicationContext) {((GenericApplicationContext) context).setResourceLoader(this.resourceLoader);}if (context instanceof DefaultResourceLoader) {((DefaultResourceLoader) context).setClassLoader(this.resourceLoader.getClassLoader());}}}

初始化ApplicationContextInitializer，执行所有ApplicationContextInitializer类的initialize方法，赋值在SpringApplication的构造方法中

org.springframework.boot.context.config.DelegatingApplicationContextInitializer@f440ae7, org.springframework.boot.autoconfigure.SharedMetadataReaderFactoryContextInitializer@5351a81e, org.springframework.boot.context.ContextIdApplicationContextInitializer@38bd9799, org.springframework.boot.context.ConfigurationWarningsApplicationContextInitializer@2884f688, org.springframework.boot.web.context.ServerPortInfoApplicationContextInitializer@7b8c24d, org.springframework.boot.autoconfigure.logging.ConditionEvaluationReportLoggingListener@59f79bfc, org.springframework.boot.devtools.restart.RestartScopeInitializer@d22de04

	protected void applyInitializers(ConfigurableApplicationContext context) {for (ApplicationContextInitializer initializer : getInitializers()) {Class<?> requiredType = GenericTypeResolver.resolveTypeArgument(initializer.getClass(), ApplicationContextInitializer.class);Assert.isInstanceOf(requiredType, context, "Unable to call initializer.");initializer.initialize(context);}}

 

 context.getBeanFactory();获取beanFactory ，赋值在GenericApplicationContext类中，此类是AnnotationConfigServletWebServerApplicationContext父类

	public GenericApplicationContext() {this.beanFactory = new DefaultListableBeanFactory();}

重点关注一下load方法，加载启动类到spring容器

一直跟进load方法会找到AnnotatedBeanDefinitionReader类的doRegisterBean方法负责注册启动类，注册通俗上来讲将启动类存入DefaultListableBeanFactory类的this.beanDefinitionMap（ConcurrentHashMap）变量中。

	<T> void doRegisterBean(Class<T> annotatedClass, @Nullable Supplier<T> instanceSupplier, @Nullable String name,@Nullable Class<? extends Annotation>[] qualifiers, BeanDefinitionCustomizer... definitionCustomizers) {AnnotatedGenericBeanDefinition abd = new AnnotatedGenericBeanDefinition(annotatedClass);if (this.conditionEvaluator.shouldSkip(abd.getMetadata())) {return;}abd.setInstanceSupplier(instanceSupplier);ScopeMetadata scopeMetadata = this.scopeMetadataResolver.resolveScopeMetadata(abd);abd.setScope(scopeMetadata.getScopeName());String beanName = (name != null ? name : this.beanNameGenerator.generateBeanName(abd, this.registry));AnnotationConfigUtils.processCommonDefinitionAnnotations(abd);if (qualifiers != null) {for (Class<? extends Annotation> qualifier : qualifiers) {if (Primary.class == qualifier) {abd.setPrimary(true);}else if (Lazy.class == qualifier) {abd.setLazyInit(true);}else {abd.addQualifier(new AutowireCandidateQualifier(qualifier));}}}for (BeanDefinitionCustomizer customizer : definitionCustomizers) {customizer.customize(abd);}BeanDefinitionHolder definitionHolder = new BeanDefinitionHolder(abd, beanName);definitionHolder = AnnotationConfigUtils.applyScopedProxyMode(scopeMetadata, definitionHolder, this.registry);BeanDefinitionReaderUtils.registerBeanDefinition(definitionHolder, this.registry);}

 

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