SpringAOP

SpringAOP：面向切面编程，常见应用场景有权限、事务、控制、日志等。
SpringAOP的原理：使用cglib代理设计模式。

用注解来模拟一下Spring的AOP

1、创建一个切面类=

/**
 * 定义一个切面类
 * @author 紫炎易霄
 */
@Component
@Aspect
public class TranAop {
	@Before("execution(* com.zyyx.service.UserService.*(..))")
	public void before(){
		System.out.println("前置通知！");
	}
	@After("execution(* com.zyyx.service.UserService.*(..))")
	public void after(){
		System.out.println("后置通知！");
	}
	@AfterThrowing("execution(* com.zyyx.service.UserService.*(..))")
	public void throwing(){
		System.out.println("异常通知！");
	}
	@AfterReturning("execution(* com.zyyx.service.UserService.*(..))")
	public void returning(){
		System.out.println("返回通知！");
	}
	@Around("execution(* com.zyyx.service.UserService.*(..))")
	public void arounding(ProceedingJoinPoint pJoinPoint) throws Throwable{
		System.out.println("环绕通知的开头！");
		pJoinPoint.proceed();
		System.out.println("环绕通知的结尾！");
		
	}
}

2、写一个dao和service

/**
 * dao
 * @author 紫炎易霄
 */
@Repository
public class UserDao {
	public void work(){
		System.out.println("我正在执行插入数据的操作！");
	}
}

/**
 * service
 * @author 紫炎易霄
 */
@Service
public class UserService {
	@Autowired
	private UserDao userDao;
	public void work(){
		userDao.work();
	}
}

3、beans.xml文件的配置

<!-- 开启dao和service的扫描注解 -->
        <context:component-scan base-package="com.zyyx"/>
        <!-- 开启aop注解 -->
        <aop:aspectj-autoproxy/>

4、、单元测试

public class TestSpringAop {
	public static void main(String[] args) {
		ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
		UserService userService = (UserService) ac.getBean("userService");
		userService.work();
	}
}

运行结果

用XML来模拟一下Spring的AOP

1、将切面类的注解清空

/**
 * 定义一个切面类
 * @author 紫炎易霄
 */
public class TranAop {
	public void before(){
		System.out.println("前置通知！");
	}
	public void after(){
		System.out.println("后置通知！");
	}
	public void throwing(){
		System.out.println("异常通知！");
	}
	public void returning(){
		System.out.println("返回通知！");
	}
	public void arounding(ProceedingJoinPoint pJoinPoint) throws Throwable{
		System.out.println("环绕通知的开头！");
		pJoinPoint.proceed();
		System.out.println("环绕通知的结尾！");
	}
}

2、配置xml文件

 <!-- 开启dao和service的扫描注解 -->
        <context:component-scan base-package="com.zyyx"/>
        <bean id="tranAop" class="com.zyyx.aop.TranAop" />
		<!-- aop的配置 -->
		<aop:config>
			<!-- 切入点 -->
			<aop:pointcut expression="execution(* com.zyyx.service.UserService.*(..))" id="point"/>
			<!-- 切面 -->
			<aop:aspect ref="tranAop">
				<!-- 通知 -->
				<aop:before method="before" pointcut-ref="point"/>
				<aop:after method="after" pointcut-ref="point"/>
				<aop:after-throwing method="throwing" pointcut-ref="point"/>
				<aop:around method="arounding" pointcut-ref="point"/>
				<aop:after-returning method="returning" pointcut-ref="point"/>
			</aop:aspect>
		</aop:config>

运行结果