设计模式-模板方法设计模式--Template Method design pattern

/**
 * Abstract implementation of the {@link org.springframework.context.ApplicationContext}
 * interface. Doesn't mandate the type of storage used for configuration; simply
 * implements common context functionality. Uses the Template Method design pattern,
 * requiring concrete subclasses to implement abstract methods.
 *
 * <p>In contrast to a plain BeanFactory, an ApplicationContext is supposed
 * to detect special beans defined in its internal bean factory:
 * Therefore, this class automatically registers
 * {@link org.springframework.beans.factory.config.BeanFactoryPostProcessor BeanFactoryPostProcessors},
 * {@link org.springframework.beans.factory.config.BeanPostProcessor BeanPostProcessors}
 * and {@link org.springframework.context.ApplicationListener ApplicationListeners}
 * which are defined as beans in the context.
 *
 * <p>A {@link org.springframework.context.MessageSource} may also be supplied
 * as a bean in the context, with the name "messageSource"; otherwise, message
 * resolution is delegated to the parent context. Furthermore, a multicaster
 * for application events can be supplied as "applicationEventMulticaster" bean
 * of type {@link org.springframework.context.event.ApplicationEventMulticaster}
 * in the context; otherwise, a default multicaster of type
 * {@link org.springframework.context.event.SimpleApplicationEventMulticaster} will be used.
 *
 * <p>Implements resource loading through extending
 * {@link org.springframework.core.io.DefaultResourceLoader}.
 * Consequently treats non-URL resource paths as class path resources
 * (supporting full class path resource names that include the package path,
 * e.g. "mypackage/myresource.dat"), unless the {@link #getResourceByPath}
 * method is overwritten in a subclass.

　

今天看spring的代码，AbstractApplicationContext中的注释有提到Template Method design pattern ，就查了一下这种设计模式。

参考：https://blog.csdn.net/qq_24692041/article/details/60961880

这种设计模式，就是在父类中定义处理流程的框架，在子类中实现具体的处理方式。我的理解是，父类处理步骤，子类处理数据。其中父类的方法基于里氏转换原则，要final掉。