spring－容器4－初始化完成

容器初始化总体流程

九

• 初始化conversion service
• 对LoadTimeWeaverAware接口bean进行实例化，依赖注入等初始化
• 冻结配置，beanDefinition不可再修改
• 预实例化非lazy-init配置的单例bean

protected void finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory) {
    // Initialize conversion service for this context.
    if (beanFactory.containsBean(CONVERSION_SERVICE_BEAN_NAME) &&
            beanFactory.isTypeMatch(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class)) {
        beanFactory.setConversionService(
                beanFactory.getBean(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class));
    }

    // Initialize LoadTimeWeaverAware beans early to allow for registering their transformers early.
    String[] weaverAwareNames = beanFactory.getBeanNamesForType(LoadTimeWeaverAware.class, false, false);
    for (String weaverAwareName : weaverAwareNames) {
        getBean(weaverAwareName);
    }

    // Stop using the temporary ClassLoader for type matching.
    beanFactory.setTempClassLoader(null);

    // Allow for caching all bean definition metadata, not expecting further changes.
    beanFactory.freezeConfiguration();

    // Instantiate all remaining (non-lazy-init) singletons.
    beanFactory.preInstantiateSingletons();
}

9.1 非lazy-init

• 1 遍历beanDefinitionNames数组，
• 2 获取name对应的beanDefinition，对于单例bean，没abstract，且为这是lazy-init属性的，则进行初始化.
• 3 对于工厂bean，&＋bean name表示工厂bean本身，根据名字获取对应beanDefinition， getBean()初始化bean实例，依赖注入
• 4 非工厂bean， getBean()初始化bean实例，依赖注入
• 5 遍历name，获取单例bean对象中SmartInitializingSingleton接口类型的对象。
• 6 调用接口方法，在所有单例bean实例化完成后，进行一些后置处理

public void preInstantiateSingletons() throws BeansException {
    if (this.logger.isDebugEnabled()) {
        this.logger.debug("Pre-instantiating singletons in " + this);
    }

    List beanNames = new ArrayList(this.beanDefinitionNames);

    // Trigger initialization of all non-lazy singleton beans...
    for (String beanName : beanNames) {//1
        RootBeanDefinition bd = getMergedLocalBeanDefinition(beanName);//2
        if (!bd.isAbstract() && bd.isSingleton() && !bd.isLazyInit()) {//2
            if (isFactoryBean(beanName)) {//3
                final FactoryBean factory = (FactoryBean) getBean(FACTORY_BEAN_PREFIX + beanName);
                boolean isEagerInit;
                if (System.getSecurityManager() != null && factory instanceof SmartFactoryBean) {
                    isEagerInit = AccessController.doPrivileged(new PrivilegedAction() {
                        @Override
                        public Boolean run() {
                            return ((SmartFactoryBean) factory).isEagerInit();
                        }
                    }, getAccessControlContext());
                }
                else {
                    isEagerInit = (factory instanceof SmartFactoryBean &&
                            ((SmartFactoryBean) factory).isEagerInit());
                }
                if (isEagerInit) {
                    getBean(beanName);
                }
            }
            else {//4
                getBean(beanName);
            }
        }
    }

    // Trigger post-initialization callback for all applicable beans...
    for (String beanName : beanNames) {
        Object singletonInstance = getSingleton(beanName);
        if (singletonInstance instanceof SmartInitializingSingleton) {//5
            final SmartInitializingSingleton smartSingleton = (SmartInitializingSingleton) singletonInstance;
            if (System.getSecurityManager() != null) {
                AccessController.doPrivileged(new PrivilegedAction