Spring启动研究2.AbstractApplicationContext.obtainFreshBeanFactory()研究

据说这个方法里面调用了loadBeanDefinitions，据说很重要，并且跟我感兴趣的标签解析有关，所以仔细看看

obtainFreshBeanFactory()这个方法在AbstractApplicationContext中定义如下：

protected ConfigurableListableBeanFactory obtainFreshBeanFactory() {
        refreshBeanFactory();
        ConfigurableListableBeanFactory beanFactory = getBeanFactory();
        if (logger.isDebugEnabled()) {
            logger.debug("Bean factory for " + getDisplayName() + ": " + beanFactory);
        }
        return beanFactory;
    }

其中refreshBeanFactory()方法也在这方法中，是个抽象方法，所以往回找EmbeddedWebApplicationContext的父类的父类GenericApplicationContext总找到了这个方法的实现：

@Override
    protected final void refreshBeanFactory() throws IllegalStateException {
        if (this.refreshed) {
            throw new IllegalStateException(
                    "GenericApplicationContext does not support multiple refresh attempts: just call 'refresh' once");
        }
        this.beanFactory.setSerializationId(getId());
        this.refreshed = true;
    }

但是好像没有我感兴趣的部分，

那看看AbstractApplicationContext类中obtainFreshBeanFactory()方法中ConfigurableListableBeanFactory beanFactory = getBeanFactory()这一段

它也是在GenericApplicationContext实现的：

@Override
    public final ConfigurableListableBeanFactory getBeanFactory() {
        return this.beanFactory;
    }

而这个类的构造方法中初始化了beanFactory：

public class GenericApplicationContext extends AbstractApplicationContext implements BeanDefinitionRegistry {

    private final DefaultListableBeanFactory beanFactory;

    private ResourceLoader resourceLoader;

    private boolean refreshed = false;

    /**
     * Create a new GenericApplicationContext.
     * @see #registerBeanDefinition
     * @see #refresh
     */
    public GenericApplicationContext() {
        this.beanFactory = new DefaultListableBeanFactory();
    }
略　　

感觉没什么内容，就是返回了一个new DefaultListableBeanFactory();