aop

aop的作用：再不更改源代码的基础上增强功能。

 

@Component
@Aspect
public class MyAdvice {
    @Pointcut("execution(void com.itheima.*.BookDao.update())")
    private void pt(){

    }
    @Before("pt()")
    public void method(){
        System.out.println(System.currentTimeMillis());
    }
}

@Configuration//证明这个类是spring的配置文件类
@ComponentScan("com.itheima")//扫描的哪些包下有注解
@EnableAspectJAutoProxy
public class SpringConfig {

}

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-test</artifactId>
    <version>5.2.10.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.9.4</version>
</dependency>