<dependencies>
    <!--包含Spring AOP:有基本的AOP功能-->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.2.10.RELEASE</version>
    </dependency>
    <!--AspectJ框架有更強(qiáng)大的AOP功能-->
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.9.5</version>
    </dependency>
</dependencies>

/*UserDao接口*/
public interface UserDao {
    public void save();
    public int update();
}
/*UserDaoImpl實(shí)現(xiàn)類*/
@Repository
public class UserDaoImpl implements UserDao {
    @Override
    public void save() {
        System.out.println("正在執(zhí)行 UserDao 的 save 方法");
    }
    @Override
    public int update() {
        System.out.println("正在執(zhí)行 UserDao 的 update 方法");
        return 1;
    }
}

/*通知類*/
@Component//將這個(gè)類定義成 Bean
@Aspect//將這個(gè)Bean定義為切面
public class MyAdvice {
    //指定UserDao類中的save方法為切入點(diǎn)
    @Pointcut("execution(void com.bighorn.dao.UserDao.save())")
    private void pt1(){}
    //指定UserDao類中的update方法為切入點(diǎn)
    @Pointcut("execution(int com.bighorn.dao.UserDao.update())")
    private void pt2(){}
}

/*Spring核心配置類*/
@Configuration
@ComponentScan("com.bighorn") //開(kāi)啟注解掃描
@EnableAspectJAutoProxy //開(kāi)啟 AspectJ 的自動(dòng)代理
public class SpringConfig {
}

public class App {
    public static void main(String[] args) throws SQLException {
        //獲取配置類初始化容器
        ApplicationContext context = new AnnotationConfigApplicationContext(SpringConfig.class);
        //從容器中獲取UserDao對(duì)象
        UserDao userDao = context.getBean(UserDao.class);
        //調(diào)用userDao的方法
        userDao.save();
    }
}

//前置通知
@Before("pt1()")
public void before() {
    System.out.println("before advice ...");
}
//后置通知
@After("pt1()")
public void after() {
    System.out.println("after advice ...");
}
//返回后通知
@AfterReturning("pt1()")
public void afterReturning() {
    System.out.println("afterReturning advice ...");
}
//異常后通知
@AfterThrowing("pt1()")
public void afterThrowing() {
    System.out.println("afterThrowing advice ...");
}

/**
     * 環(huán)繞通知需要攜帶ProceedingJoinPoint類型的參數(shù)
     * 環(huán)繞通知類似于動(dòng)態(tài)代理的全過(guò)程：ProceedingJoinPoint類型的參數(shù)可以決定是否執(zhí)行目標(biāo)方法
     * 環(huán)繞通知必須要有返回值，返回值即為目標(biāo)方法的返回值
     * @param pjp
     * @return Object
     */
@Around("pt2()")
public Object around(ProceedingJoinPoint pjp) {
    Object result = null;
    try {
        System.out.println("這是環(huán)繞通知中的前置通知......");
        //執(zhí)行目標(biāo)方法
        result = pjp.proceed();
        System.out.println("這是環(huán)繞通知中的返回通知......");
    } catch (Throwable e) {
        System.out.println("這是環(huán)繞通知中的異常通知......");
    }
    System.out.println("這是環(huán)繞通知中的后置通知......");
    return result;
}

public class App {
    public static void main(String[] args) throws SQLException {
        //獲取配置類初始化容器
        ApplicationContext context = new AnnotationConfigApplicationContext(SpringConfig.class);
        //從容器中獲取UserDao對(duì)象
        UserDao userDao = context.getBean(UserDao.class);
        //調(diào)用userDao的update方法
        userDao.update();
    }
}