spring-基于注解的aop开发（快速入门）

步骤：
1.导入坐标

<dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.13</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>5.0.5.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.0.5.RELEASE</version>
    </dependency>
    <dependency>
      <groupId>org.aspectj</groupId>
      <artifactId>aspectjweaver</artifactId>
      <version>1.8.4</version>
    </dependency>

2.创建目标类和接口（内部有切点）

public interface TargetInterface {
    public void save();
}

@Component
public class Target implements TargetInterface{
    public void save() {
        System.out.println("save running....");
    }
}

3.创建切面类（内部有增强方法）

@Component
@Aspect   //标注当前aspect是切面类
public class MyAspect {
	//配置织入关系   value=切点表达式
    @Before(value = "execution(public void com.hao.anno.Target.save())")
    public void before(){
        System.out.println("前置增强...");
    }
    public void afterReturning(){
        System.out.println("后置增强...");
    }
    public Object around(ProceedingJoinPoint point) throws Throwable {      //切入点
        System.out.println("环绕前增强...");
        //切点方法
        Object proceed = point.proceed();
        System.out.println("环绕后增强...");
        return proceed;
    }
}

4.将目标类和切面类的对象创建权交给spring
5.在切面类中使用注解配置织入关系
第三步和第二步已经实现
6.在配置文件中开启组件扫描和aop自动代理

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

<!--    组件扫描-->
    <context:component-scan base-package="com.hao.anno"></context:component-scan>

<!--    aop自动代理-->
    <aop:aspectj-autoproxy/>
</beans>

7.测试

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContextanno.xml")
public class AnnoTest {

        @Autowired
        private TargetInterface target;

        @Test
        public void test2(){
            target.save();
        }

}

结果：
前置增强…
save running…