Spring AOP基于注解使用方法和实现

素颜马尾好姑娘i 2023-06-06 10:44 14阅读 0赞

1、AOP main方法

public static void main(String[] args) {
            //1、创建Spring的容器
            ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContextXml.xml");
            //2、从IOC容器中获取bean的实例
            AopUserService aopUserService = ctx.getBean(AopUserService.class);
            //3、使用bean
            int result = aopUserService.add(3, 8);
            System.out.println("result:"+result);
    
            result = aopUserService.mul(13, 8);
            System.out.println("result:"+result);
    
            result = aopUserService.sub(3, 8);
            System.out.println("result:"+result);
    
            result = aopUserService.div(32, 4);
            System.out.println("result:"+result);
    
        }

2、写一个接口

@Service
    public interface AopUserService {
        public int add(int x, int y);
        public int mul(int x, int y);
        public int sub(int x, int y);
        public int div(int x, int y);
    }

3、实现接口的方法

@Service
    public class AopUserServiceImpl implements AopUserService {
        @Override
        public int add(int x, int y) {
            int result = x + y;
            return result;
        }
        @Override
        public int mul(int x, int y) {
            int result = x - y;
            return result;
        }
        @Override
        public int sub(int x, int y) {
            int result = x * y;
            return result;
        }
        @Override
        public int div(int x, int y) {
            int result = x / y;
            return result;
        }
    }

4、定一个类，开始写AOP

/**
     * @Order(1)：切面的优先级，值越小，优先级越高
     */
    @Order(1)
    @Aspect
    @Component
    public class UserAspect {
        /**
         * 定义一个方法，用于声明切入点的表达式，一般该方法中不再需要添加其它代码
         */
        @Pointcut("execution(public int main.cn.com.fullstackxml.services.AopUserService.*(..))")
        public void declareJoint(){}
        /**
         * 声明该方法是一个前置方法，在目标方法开始之前执行
         * @param joinPoint
         */
        @Before("declareJoint()")
        public void beforeMethod(JoinPoint joinPoint) {
            String name = joinPoint.getSignature().getName();
            List<Object> args = Arrays.asList(joinPoint.getArgs());
            System.out.println("1、--->the method " + name + " begins" + args);
        }
        /**
         * 后置通知是在连接点完成之后执行，即连接点返回结果或都抛出异常的时候，下面的后置通知记录了方法终止，
         * 一个切面可以包含一个或多个通知，在后置通知中不能访问目标方法的执行结果
         * @param joinPoint
         */
        @After("declareJoint()")
        public void afterMethod(JoinPoint joinPoint) {
            String name = joinPoint.getSignature().getName();
            List<Object> args = Arrays.asList(joinPoint.getArgs());
            System.out.println("the method " + name + " end: ");
        }
        /**
         * 返回通知
         * @param joinPoint
         * @param result
         */
        @AfterReturning(value = "declareJoint()", returning = "result")
        public void afterReturning(JoinPoint joinPoint, Object result) {
            String name = joinPoint.getSignature().getName();
            List<Object> args = Arrays.asList(joinPoint.getArgs());
            System.out.println("the method " + name + " end: " + result);
        }
        /**
         * 异常通知
         * @param joinPoint
         * @param ex
         */
        @AfterThrowing(value = "declareJoint()",throwing = "ex")
        public void AfterThrowing(JoinPoint joinPoint,Exception ex){
            String name = joinPoint.getSignature().getName();
            System.out.println("the method " + name + " exction: " + ex);
        }
    }

5、定义另一个类，验证AOP

@Order(2)
    @Aspect
    @Component
    public class ValiidateAspect {
        /**
         * 引入外部切入点表达式，类名加方法，如果不在同一包下，还需要加上包名
         * @param joinPoint
         */
        @Before("UserAspect.declareJoint()")
        public void validate(JoinPoint joinPoint){
            System.out.println("2、------>validate:"+ Arrays.asList(joinPoint.getArgs()));
        }
    }

6、定义xml配置文件

<?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:context="http://www.springframework.org/schema/context"
           xmlns:aop="http://www.springframework.org/schema/aop"
           xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
        
        
        <context:component-scan base-package="main.cn.com.fullstackxml" use-default-filters="false">
            <context:include-filter type="annotation" expression="org.springframework.stereotype.Repository"/>
            <context:include-filter type="annotation" expression="org.springframework.stereotype.Service"/>
            <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
            <context:include-filter type="annotation" expression="org.springframework.stereotype.Component"/>
        </context:component-scan>
        
        <aop:aspectj-autoproxy></aop:aspectj-autoproxy>
    </beans>