Spring - AOP之探秘

经典的无法拦截内部方法调用案例：

package com.imooc.service;

import com.imooc.config.ApplicationContextHolder;
import org.springframework.aop.framework.AopContext;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Component;
import java.util.Arrays;
import java.util.List;

@Component
public class MenuService {

    @Cacheable(cacheNames = {"menu"})
    public List<String> getMenuList(){
        System.out.println("");
        System.out.println("mock:get from db");
        return Arrays.asList("article","comment","admin");
    }

    public List<String> getRecommends(){
        return this.getMenuList();
    }
}

Ps：不会启动AOP： 因为是通过 this 调用，哪怕该方法上有切面注解，但获取不到Bean的原因，所以注解也会失效。

解决方案：通过代理来调用该方法，而不是通过 this 来调用。

package com.imooc.service;

import com.imooc.config.ApplicationContextHolder;
import org.springframework.aop.framework.AopContext;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Component;
import java.util.Arrays;
import java.util.List;

@Component
public class MenuService {

    @Cacheable(cacheNames = {"menu"})
    public List<String> getMenuList(){
        System.out.println("");
        System.out.println("mock:get from db");
        return Arrays.asList("article","comment","admin");
    }

    public List<String> getRecommends(){
        MenuService proxy = ApplicationContextHolder.getContext().getBean(MenuService.class);
        return proxy.getMenuList();
    }
}

package com.imooc.config;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

@Component
public class ApplicationContextHolder implements ApplicationContextAware {

    private static ApplicationContext ctx;

    public static ApplicationContext getContext() {
        return ctx;
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        ctx = applicationContext;
    }
}

• 源码下载地址​​SpringAOP之探秘（动态代理、责任链模式、注解使用）_spring责任链模式,责任链注解-Java代码类资源-CSDN下载​​