启动类ClassPathXmlApplicationContext

public ClassPathXmlApplicationContext(
			String[] configLocations, boolean refresh, @Nullable ApplicationContext parent)
			throws BeansException {

		super(parent);
		setConfigLocations(configLocations);
		if (refresh) {
			refresh();
		}
	}

其中的父类构造方法：

super(parent);

02
ClassPathXmlApplicationContext 继承 AbstractXmlApplicationContext：

public class ClassPathXmlApplicationContext extends AbstractXmlApplicationContext

AbstractXmlApplicationContext的构造方法：

	public AbstractXmlApplicationContext(@Nullable ApplicationContext parent) {
		super(parent);
	}

03.AbstractXmlApplicationContext 继承 AbstractRefreshableConfigApplicationContext

AbstractRefreshableConfigApplicationContext的构造方法：

public AbstractRefreshableConfigApplicationContext(@Nullable ApplicationContext parent) {
		super(parent);
	}

04.AbstractRefreshableConfigApplicationContext 继承 AbstractRefreshableApplicationContext

AbstractRefreshableApplicationContext的构造方法：

	public AbstractRefreshableApplicationContext(@Nullable ApplicationContext parent) {
		super(parent);
	}

05.AbstractRefreshableApplicationContext 继承 AbstractApplicationContext

AbstractApplicationContext的构造方法：

public AbstractApplicationContext(@Nullable ApplicationContext parent) {
		this();
		setParent(parent);
	}

public AbstractApplicationContext() {
		this.resourcePatternResolver = getResourcePatternResolver();
	}

getResourcePatternResolver（） 解析资源的函数，比如xml文件

protected ResourcePatternResolver getResourcePatternResolver() {
		return new PathMatchingResourcePatternResolver(this);
	}

/** Logger used by this class. Available to subclasses. */
//日志
	protected final Log logger = LogFactory.getLog(getClass());

	/** Unique id for this context, if any. */
	//唯一标识符
	private String id = ObjectUtils.identityToString(this);

	/** Display name. */
	private String displayName = ObjectUtils.identityToString(this);

/** Parent context. */
	@Nullable
	private ApplicationContext parent;

	/** Environment used by this context. */
	@Nullable
	private ConfigurableEnvironment environment;

	/** BeanFactoryPostProcessors to apply on refresh. */
	private final List<BeanFactoryPostProcessor> beanFactoryPostProcessors = new ArrayList<>();

	/** System time in milliseconds when this context started. */
	private long startupDate;

	/** Flag that indicates whether this context is currently active. */
	private final AtomicBoolean active = new AtomicBoolean();

	/** Flag that indicates whether this context has been closed already. */
	private final AtomicBoolean closed = new AtomicBoolean();

	/** Synchronization monitor for the "refresh" and "destroy". */
	private final Object startupShutdownMonitor = new Object();


	@Nullable
	private Thread shutdownHook;

	/** ResourcePatternResolver used by this context. */
	private final ResourcePatternResolver resourcePatternResolver;

	/** LifecycleProcessor for managing the lifecycle of beans within this context. */
	@Nullable
	private LifecycleProcessor lifecycleProcessor;

	/** MessageSource we delegate our implementation of this interface to. */
	@Nullable
	private MessageSource messageSource;