AOP 切面的使用，以及如何在通知上获取切入方法的注解和参数

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/qq_30698633/article/details/77917064

1、自定义注解

@Retention(RetentionPolicy.RUNTIME)
@Target(value=ElementType.METHOD)
public @interface AdviceAnnotation {

	String name();
}

2、service层

public interface AdviceService {

	void study(String name) throws Exception;
}

3、实现类

@Service
public class AdviceServiceImpl implements AdviceService {

	
	@AdviceAnnotation(name = "我是注解name！！！")
	public void study(String name) throws Exception {
		System.out.println("好好学习，天天向上");
		
		throw new Exception("my god!!");
	}

}

4、切面

@Aspect       // 切面注解
@Component
public class StudyAdvice {

	@Before(value = "execution(* com.teng.advice.service.impl.AdviceServiceImpl.study(..))"
            + "&& args(name)",argNames="name")
    private void studyBefore(String name){
        System.out.println(String.format("获取到的参数：%s", name));    // 获取切入方法上的参数
        System.out.println("学习之前先打局游戏！");
    }
	
	@After(value="@annotation(com.teng.advice.annotation.AdviceAnnotation) &&"
			+ "execution(* com.teng.advice..*.*(..))")
	private void studyAfter(AdviceAnnotation ad){
		
		System.out.println("学累了再打局游戏！");
	}
	
	@Around("execution(* com.teng.advice..*.*(..)) && @annotation(ad)")
	private Object studyAround(ProceedingJoinPoint pjp,AdviceAnnotation ad) throws Throwable{    // 环绕通知需要有返回值
		System.out.println("前置通知：还是打游戏");
		System.out.println(String.format("注解name：%s", ad.name()));    // 获取切入方法上的注解
		Object result =  pjp.proceed();
		System.out.println("后置通知：依旧打游戏");
		return result;
	}
	
	
	@AfterThrowing(pointcut="execution(* com.teng.advice..*.*(..))",throwing="ex")
	private void studyThrow(Throwable ex){
		System.out.println(ex.getMessage());
	}

       // @AfterReturning(returning="rvt" ,pointcut="execution(* com.teng.advice..*.*(..))")          
       // public void test(Object rvt){        
       //        System.out.println("获取目标方法返回值:" + rvt);         
       //  }  

 }

5、运行

@SpringBootApplication
public class BootTestApplication 
{
    public static void main( String[] args )
    {
        SpringApplication.run(BootTestApplication.class, args);
    }
    
    @Autowired 
    private AdviceService adviceService;
    
    @PostConstruct
    public void init() throws Exception{
    	adviceService.study("小耿");
    }
}

6、打印结果

前置通知：还是打游戏
注解name：我是注解name！！！
获取到的参数：小耿
学习之前先打局游戏！
好好学习，天天向上
学累了再打局游戏！
my god!!