01.AOP简介

AOP的概念

AOP思想的实现方案

模拟AOP的基础代码

public class MockAopBeanPostProcessor implements BeanPostProcessor, ApplicationContextAware {

    private ApplicationContext applicationContext;

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        // 对 com.nju.service.impl 下的类进行增强
        if (bean.getClass().getPackage().getName().equals("com.nju.service.impl")) {
            // 动态代理
            Object beanProxy = Proxy.newProxyInstance(
                    bean.getClass().getClassLoader(),
                    bean.getClass().getInterfaces(),
                    (Object proxy, Method method, Object[] args) -> {
                        // MyAdvice是用来增强的类
                        MyAdvice myAdvice = applicationContext.getBean(MyAdvice.class);
                        myAdvice.beforeAdvice();
                        Object result = method.invoke(bean, args);
                        myAdvice.afterAdvice();
                        return result;
                    }
            );
            return beanProxy;
        }
        
        return bean;
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        // 注入上下文
        this.applicationContext = applicationContext;
    }
}

AOP相关概念