一、寻找外围办法
// == 入口public static void main(String[] args) { SpringApplication.run(SpringRunner.class, args);}// == 调用链org.springframework.boot.SpringApplication#run(java.lang.Class<?>, java.lang.String...)org.springframework.boot.SpringApplication#run(java.lang.Class<?>[], java.lang.String[])org.springframework.boot.SpringApplication#run(java.lang.String...)org.springframework.boot.SpringApplication#refreshContextorg.springframework.boot.SpringApplication#refresh
记住refresh办法
,它十分重要
察看它的外部实现:
// ##### IOC容器初始化 ##### // 告知子类要初始化BeanFactory// BeanDefinition信息的读取是在子类的refreshBeanFactory()办法里实现的ConfigurableListableBeanFactory beanFactory = this.obtainFreshBeanFactory();// 筹备bean工厂以在此上下文中应用。this.prepareBeanFactory(beanFactory);// ##### 驰名的九大办法 ##### try { // 设置beanFactory的后置解决 postProcessBeanFactory(beanFactory); // 调用beanFactory的后置解决,如springboot主动拆卸获取配置的Entity invokeBeanFactoryPostProcessors(beanFactory); // 注册beanFactory的后置解决 registerBeanPostProcessors(beanFactory); // 初始化上下文的音讯 initMessageSource(); // 初始化高低的事件 initApplicationEventMulticaster(); // 初始化一些非凡的bean onRefresh(); // 查看一些监听的bean并注册到容器中 registerListeners(); // Instantiate all remaining (non-lazy-init) singletons,spring bean对象初始化在这里 finishBeanFactoryInitialization(beanFactory); // 公布容器事件,完结Refresh过程 finishRefresh();
二、注册和扫描
本节深入分析构建BeanFactory的过程。
ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();// == 调用链 org.springframework.context.support.AbstractApplicationContext#obtainFreshBeanFactoryorg.springframework.context.support.AbstractRefreshableApplicationContext#refreshBeanFactory// -- 剖析注解形式注入org.springframework.web.context.support.AnnotationConfigWebApplicationContext#loadBeanDefinitions
1.向容器注册对象信息
注入的实质就是向容器(也有叫上下文的,就是Context的直译)——本质就是一个Map注册类的形容信息。
用代码形容就是:beanDefinitionMap.put(BeanDefinition)
看看具体实现:
// == 注册逻辑protected void loadBeanDefinitions(DefaultListableBeanFactory beanFactory) { AnnotatedBeanDefinitionReader reader = getAnnotatedBeanDefinitionReader(beanFactory); if (!this.annotatedClasses.isEmpty()) { reader.register(this.annotatedClasses.toArray(new Class<?>[this.annotatedClasses.size()])); }}// == 调用链org.springframework.context.annotation.AnnotatedBeanDefinitionReader#registerorg.springframework.context.annotation.AnnotatedBeanDefinitionReader#registerBean(java.lang.Class<?>)org.springframework.context.annotation.AnnotatedBeanDefinitionReader#doRegisterBean
这个办法值得细说一下:
<T> void doRegisterBean(Class<T> annotatedClass, @Nullable Supplier<T> instanceSupplier, @Nullable String name, @Nullable Class<? extends Annotation>[] qualifiers, BeanDefinitionCustomizer... definitionCustomizers) { //## 被注解润饰的对象,会被封装成BeanDefinition构造 AnnotatedGenericBeanDefinition abd = new AnnotatedGenericBeanDefinition(annotatedClass); //为注解Bean定义生成Bean名称 String beanName = (name != null ? name : this.beanNameGenerator.generateBeanName(abd, this.registry)); // BeanDefinition再次封装 BeanDefinitionHolder definitionHolder = new BeanDefinitionHolder(abd, beanName); // ## 注入 BeanDefinitionReaderUtils.registerBeanDefinition(definitionHolder, this.registry);}// == 调用链org.springframework.beans.factory.support.BeanDefinitionReaderUtils#registerBeanDefinition// -- 后面创立的工厂是DefaultListableBeanFactoryorg.springframework.beans.factory.support.DefaultListableBeanFactory#registerBeanDefinition
最终的注入逻辑:
// 存储注册信息的BeanDefinitionprivate final Map<String, BeanDefinition> beanDefinitionMap = new ConcurrentHashMap<>(256);public void registerBeanDefinition(String beanName, BeanDefinition beanDefinition) throws BeanDefinitionStoreException { // ## 注入的实质 this.beanDefinitionMap.put(beanName, beanDefinition);}
2.扫描指定package的配置信息
无它,只为扩充扫描范畴。
默认只注入SpringRunner(Starter类)的子包
protected void loadBeanDefinitions(DefaultListableBeanFactory beanFactory) { //为容器设置类门路Bean定义扫描器 ClassPathBeanDefinitionScanner scanner = getClassPathBeanDefinitionScanner(beanFactory); if (!this.basePackages.isEmpty()) { scanner.scan(this.basePackages.toArray(new String[this.basePackages.size()])); }}// == 调用链org.springframework.context.annotation.ClassPathBeanDefinitionScanner#scanorg.springframework.context.annotation.ClassPathBeanDefinitionScanner#doScanprotected Set<BeanDefinitionHolder> doScan(String... basePackages) { //遍历扫描所有给定的包 for (String basePackage : basePackages) { // ## 同样执行注入流程 registerBeanDefinition(definitionHolder, this.registry); }}
未完待续(懒癌发生……)