使用注解实现AOP

末蓝、 2022-05-08 00:38 192阅读 0赞

**xml头文件中加入：**

xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/context
              http://www.springframework.org/schema/context/spring-context.xsd"

**声明哪些包下有注解（当有两个以上的包时，用“，”隔开）**

<context:component-scan base-package="com.lee.advice,com.lee.test"></context:component-scan>

**在demo类中加入@Component  
在方法上添加@Pointcut 定义切点**

@Component
    public class Demo {
    	@Pointcut("execution(* com.lee.service.Demo.demo())")
    	public void demo() {
    		System.out.println("demo.exe");
    	}
    }

相当于<bean>,如果@Component后不加参数，bean的id就是类名首字母小写，如果@Component(“abc”),则id就相当于abc.  
**在通知类中**  
@Component类被spring管理  
@Aspect相当于<aop:aspect>标签

@Component
    @Aspect
    public class MyAdvice {
    	@Before("com.lee.service.Demo.demo()")
    	public void before() {
    		System.out.println("before");
    	}
    }

测试类

public class Test {
    	public static void main(String[] args) {
    		ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
    		String[] names = ac.getBeanDefinitionNames();
    		System.out.println(Arrays.toString(names));
    		Demo demo = (Demo)ac.getBean("demo");
    		demo.demo();
    	}
    }

输出

[myAdvice, demo, org.springframework.context.annotation.internalConfigurationAnnotationProcessor, org.springframework.context.annotation.internalAutowiredAnnotationProcessor, org.springframework.context.annotation.internalRequiredAnnotationProcessor, org.springframework.context.annotation.internalCommonAnnotationProcessor, org.springframework.context.event.internalEventListenerProcessor, org.springframework.context.event.internalEventListenerFactory, org.springframework.aop.config.internalAutoProxyCreator]
    before
    demo.exe