AOP通知获取数据

• 获取切入点方法的参数
  • JoinPoint：适用于前置、后置、返回后、抛出异常后通知
  • ProceedJointPoint：适用于环绕通知
• 获取切入点方法返回值
  • 返回后通知
  • 环绕通知
• 获取切入点方法运行异常信息
  • 抛出异常后通知
  • 环绕通知

public interface BookDao{
    public String findName(int id);
}

@Repository
public class BookDaoImpl implements BookDao{
    public String findName(int id){
        System.out.println("id: " + id);
        return "itcast";
    }
}

public class App {
    public static void main(String[] args){
        ApplicationContext ctx = new AnnotationConfigApplicationContext(SpringConfig.class);
        BookDao bookDao = ctx.getBean(BookDao.class);
        String name = bookDao.findName(100);
        System.out.println(name);
    }
}

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

    @Before("pt()")
    public void before(JoinPoint jp) {
        Object[] args = jp.getArgs();
        System.out.println(Arrays.toString(args));
        System.out.printin("before advice ...");
    }

    @After("pt()")
    public void after(JoinPoint jp) {
        Object[] args = jp.getArgs();
        System.out.println(Arrays.toString(args));
        System.out.printin("after advice ...");
    }

    @Around("pt()")
    public Object around(ProceedingJoinPoint pjp) throws Throwable {
        Object[] args = pjp.getArgs();
        System.out.println(Arrays.toString(args));
        args[0] = 666;
        Object ret = pjp.proceed(args);
       return ret;
    }

    @AfterReturning(value = "pt()", returning = "ret")
    public void afterReturning(JoinPoint jp, Object ret) { // JoinPoint 必须在 返回值参数之前
        System.out.printin("afterReturning advice ..." + ret);
    }

    @AfterThrowing(value = "pt()", throwing = "t")
    public void afterThrowing(Throwable t) {
        System.out. printin("afterThrowing advice ..." + t)；
    }
}

获取参数

获取返回值

获取异常