东莞微客巴巴做网站,wordpress 默认首页,徐州苏视在线,哈尔滨建设网站公司吗一、概述
1.1、官网 AOP的中文名称是面向切面编程或者面向方面编程#xff0c;利用AOP可以对业务逻辑的各个部分进行隔离#xff0c;从而使得业务逻辑各部分之间的耦合度降低#xff0c;提高程序的可重用性#xff0c;同时提高了开发的效率。
1.2、通俗描述 不通过…一、概述
1.1、官网 AOP的中文名称是面向切面编程或者面向方面编程利用AOP可以对业务逻辑的各个部分进行隔离从而使得业务逻辑各部分之间的耦合度降低提高程序的可重用性同时提高了开发的效率。
1.2、通俗描述 不通过修改源代码的方式在主干功能里面添加新功能。
1.3、案例说明 二、底层原理 AOP底层使用动态代理技术。有两种情况的动态代理
有接口情况JDK动态代理无接口情况CGLIB动态代理基于类的继承使用代理子类的形式对父类的方法进行重写完成方法的增强
2.1、JDK动态代理案例代码
2.1.1、UserDao
package org.star.dao;public interface UserDao {/*** 两数相加* param num1* param num2* return*/int add(int num1,int num2);/*** 根据id修改* param id* return*/int update(long id);}2.1.2、UserDaoImpl
package org.star.dao.impl;import org.star.dao.UserDao;public class UserDaoImpl implements UserDao {Overridepublic int add(int num1, int num2) {return num1 num2;}Overridepublic int update(long id) {// do your business...return 1;}
}2.1.3、MyInvocationHandler
package org.star.handler;import lombok.extern.slf4j.Slf4j;import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.util.Arrays;Slf4j
public class MyInvocationHandler implements InvocationHandler {private Object obj;public MyInvocationHandler(Object obj) {this.obj obj;}/*** 增强逻辑** return* throws Throwable*/Overridepublic Object invoke(Object proxy, Method method, Object[] args) throws Throwable {// 目标方法执行之前log.info(目标方法执行之前执行,目标方法名称:{},入参:{}, method.getName(), Arrays.toString(args));// 目标方法执行Object result method.invoke(obj, args);// 目标方法执行之后log.info(目标方法执行之后执行,result:{},obj:{},result,obj.getClass());return result;}
}2.1.4、测试类
package org.star;import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.star.dao.UserDao;
import org.star.dao.impl.UserDaoImpl;
import org.star.handler.MyInvocationHandler;import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;/*** Unit test for simple App.*/
Slf4j
public class AppTest {Testpublic void testJDKProxy1() {Class[] interfaces {UserDao.class};UserDaoImpl userDaoImpl new UserDaoImpl();UserDao userDao (UserDao) Proxy.newProxyInstance(AppTest.class.getClassLoader(),interfaces,new MyInvocationHandler(userDaoImpl));int result userDao.add(3,5);log.info(result:{},result);}Testpublic void testJDKProxy2() {Class[] interfaces {UserDao.class};UserDao userDao (UserDao) Proxy.newProxyInstance(AppTest.class.getClassLoader(), interfaces, new InvocationHandler() {UserDaoImpl userDaoImpl new UserDaoImpl();Overridepublic Object invoke(Object obj, Method method, Object[] args) throws Throwable {// 目标方法执行之前log.info(目标方法执行之前执行,目标方法名称:{},入参:{}, method.getName(), Arrays.toString(args));// 目标方法执行Object result method.invoke(userDaoImpl, args);// 目标方法执行之后log.info(目标方法执行之后执行,obj:{},userDaoImpl.getClass());return result;}});int result userDao.add(5,5);log.info(result:{},result);}}2.2、Cglib动态代理案例代码
2.2.1、pom
dependenciesdependencygroupIdcglib/groupIdartifactIdcglib/artifactIdversion3.1/version/dependencydependencygroupIdaopalliance/groupIdartifactIdaopalliance/artifactIdversion1.0/version/dependencydependencygroupIdorg.aspectj/groupIdartifactIdaspectjweaver/artifactIdversion1.9.19/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-aop/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdcommons-logging/groupIdartifactIdcommons-logging/artifactIdversion1.1.1/version/dependencydependencygroupIdcom.alibaba/groupIdartifactIddruid/artifactIdversion1.2.16/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-beans/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-context/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-core/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-expression/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdjunit/groupIdartifactIdjunit/artifactIdversion4.13.2/version/dependency!-- 普通maven项目中使用Sl4j注解 --dependencygroupIdorg.projectlombok/groupIdartifactIdlombok/artifactIdversion1.18.22/version/dependencydependencygroupIdorg.slf4j/groupIdartifactIdslf4j-api/artifactIdversion1.7.32/version/dependencydependencygroupIdch.qos.logback/groupIdartifactIdlogback-classic/artifactIdversion1.2.10/version/dependency/dependencies
2.2.2、Panda
package org.star.cglib;import lombok.extern.slf4j.Slf4j;/*** Author: * Date: 2023/8/28 14:32* Description:*/
Slf4j
public class Panda {public void eat() {log.info(熊猫吃竹子);}}2.2.3、App
package org.star;import lombok.extern.slf4j.Slf4j;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import org.star.cglib.Panda;import java.lang.reflect.Method;Slf4j
public class App {public static void main( String[] args ) {Panda panda new Panda();// 创建代理类Panda proxyPanda (Panda) Enhancer.create(Panda.class, new MethodInterceptor() {Overridepublic Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {log.info(target method before...);Object result method.invoke(panda, args);log.info(target method after...);return result;}});// 通过代理类调用目标方法实现增强proxyPanda.eat();}
}三、AOP术语
3.1、连接点 类里面哪些方法可以被增强这些被增强的方法就被称为连接点。
3.2、切入点 类里面实际真正被增强的方法称为切入点。
3.3、通知增强 实际增强的逻辑部分称为通知增强通知按照作用于目标方法的位置不同可以分为如下5种类型。
3.3.1、前置通知 前置通知因在目标方法之前执行故名前置通知注解为Before。
3.3.2、后置通知 后置通知又叫正常结束通知即目标方法正常结束后执行常用于做一些善后的操作注解为AfterReturning。
注意事项如果方法有返回值可以在通知中获取到方法的返回值
3.3.3、异常通知 异常通知故名思议是指当目标方法运行期间出现异常时才会执行注解为AfterThrowing。
3.3.4、最终通知 最终通知有点儿类似于try..catch...finally中的finally代码块不管目标方法运行期间是否出现异常都会执行用于兜底。注解为After
3.3.5、环绕通知 环绕通知是上述四个通知的集大成者一个通知等价于上述四个通知。注解为Around。
注意事项 1需要通过代码调用方法在方法执行的周围进行增强 2使用代码调用连接点方法proceedingJoinPoint.proceed() 3环绕通知需要有返回值此返回值就是方法调用的结果
3.4、切面 把通知应用到切入点的过程称为切面是动作。
四、AOP案例
4.1、基于xml配置文件实现maven
4.1.1、pom
dependenciesdependencygroupIdcglib/groupIdartifactIdcglib/artifactIdversion3.1/version/dependencydependencygroupIdaopalliance/groupIdartifactIdaopalliance/artifactIdversion1.0/version/dependencydependencygroupIdorg.aspectj/groupIdartifactIdaspectjweaver/artifactIdversion1.9.19/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-aop/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdcommons-logging/groupIdartifactIdcommons-logging/artifactIdversion1.1.1/version/dependencydependencygroupIdcom.alibaba/groupIdartifactIddruid/artifactIdversion1.2.16/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-beans/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-context/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-core/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-expression/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdjunit/groupIdartifactIdjunit/artifactIdversion4.13.2/version/dependencydependencygroupIdcom.alibaba/groupIdartifactIdfastjson/artifactIdversion1.2.76/version/dependency!-- 普通maven项目中使用Sl4j注解 --dependencygroupIdorg.projectlombok/groupIdartifactIdlombok/artifactIdversion1.18.22/version/dependencydependencygroupIdorg.slf4j/groupIdartifactIdslf4j-api/artifactIdversion1.7.32/version/dependencydependencygroupIdch.qos.logback/groupIdartifactIdlogback-classic/artifactIdversion1.2.10/version/dependency/dependencies
4.1.2、ATM
package org.star.component;import lombok.extern.slf4j.Slf4j;/*** 目标*/
Slf4j
public class ATM {public int take(int money) {log.info(取钱方法正在执行...);if (money 100) {throw new RuntimeException(自定义的异常);}return 10000;}}4.1.3、LogAspect
package org.star.aspect;import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;/*** 增强类*/
Slf4j
public class LogAspect {/*** 前置通知方法执行之前执行*/public void beforeLog() {log.info(前置通知执行...);}/*** 后置通知正常结束通知方法正常执行结束时才会通知出现异常不会执行*/public void afterReturningLog(Object result) {log.info(后置通知正常结束通知执行...返回值{},result);}/*** 异常通知*/public void afterThrowingLog(Exception ex) {log.info(异常通知目标方法出现异常时执行...异常信息{},ex.getMessage());}/*** 最终通知不管目标方法执行期间是否有异常都会执行**/public void afterLog() {log.info(最终通知不管目标方法执行期间是否有异常都会执行...);}/*** 环绕通知* param joinPoint* return*/public Object aroundLog(ProceedingJoinPoint joinPoint) {Object result null;try {log.info(around before);result joinPoint.proceed(); // 调用目标方法返回的值log.info(around afterReturning);} catch (Throwable e) {log.info(around afterThrowing);} finally {log.info(around after);}return result;}}4.1.4、applicationContext
?xml version1.0 encodingUTF-8?
beans xmlnshttp://www.springframework.org/schema/beansxmlns:xsihttp://www.w3.org/2001/XMLSchema-instance xmlns:aophttp://www.springframework.org/schema/aopxsi:schemaLocationhttp://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd!-- bean配置 --bean idatm classorg.star.component.ATM/beanbean idlogAspect classorg.star.aspect.LogAspect/bean!-- aop配置 --aop:config!--切入点说明execution中的第一个参数代表返回值*代表所有--aop:pointcut idp expressionexecution(* org.star.component.ATM.take(..))/!-- 切面 --aop:aspect reflogAspect!-- 增强作用在具体的方法上 --!-- 前置通知 --!--aop:before methodbeforeLog pointcut-refp/aop:before--!-- 后置通知正常结束通知 --!--aop:after-returning methodafterReturningLog pointcut-refp returningresult/aop:after-returning--!-- 异常通知 --!--aop:after-throwing methodafterThrowingLog pointcut-refp throwingex/aop:after-throwing--!-- 最终通知 --!--aop:after methodafterLog pointcut-refp/aop:after--!-- 环绕通知 --aop:around methodaroundLog pointcut-refp/aop:around/aop:aspect/aop:config/beans
4.1.5、AppTest
package org.star;import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.star.component.ATM;/*** Unit test for simple App.*/
Slf4j
public class AppTest {Testpublic void aopTest() {ClassPathXmlApplicationContext context new ClassPathXmlApplicationContext(applicationContext.xml);ATM atm context.getBean(ATM.class);int take atm.take(100);log.info(aopTest take:{},take);}}4.2、基于全注解方式实现maven
4.2.1、pom
dependenciesdependencygroupIdcglib/groupIdartifactIdcglib/artifactIdversion3.1/version/dependencydependencygroupIdaopalliance/groupIdartifactIdaopalliance/artifactIdversion1.0/version/dependencydependencygroupIdorg.aspectj/groupIdartifactIdaspectjweaver/artifactIdversion1.9.19/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-aop/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdcommons-logging/groupIdartifactIdcommons-logging/artifactIdversion1.1.1/version/dependencydependencygroupIdcom.alibaba/groupIdartifactIddruid/artifactIdversion1.2.16/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-beans/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-context/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-core/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-expression/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdjunit/groupIdartifactIdjunit/artifactIdversion4.13.2/version/dependencydependencygroupIdcom.alibaba/groupIdartifactIdfastjson/artifactIdversion1.2.76/version/dependency!-- 普通maven项目中使用Sl4j注解 --dependencygroupIdorg.projectlombok/groupIdartifactIdlombok/artifactIdversion1.18.22/version/dependencydependencygroupIdorg.slf4j/groupIdartifactIdslf4j-api/artifactIdversion1.7.32/version/dependencydependencygroupIdch.qos.logback/groupIdartifactIdlogback-classic/artifactIdversion1.2.10/version/dependency/dependencies
4.2.2、MySpringConfig
package org.star.config;import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;Configuration
ComponentScan(basePackages {org.star})
EnableAspectJAutoProxy(proxyTargetClass true) // 启用CGLB动态代理
public class MySpringConfig {}4.2.3、ATM
package org.star.component;import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;Slf4j
Component
public class ATM {public int take(int money) {log.info(取钱方法正在执行...);if (money 100) {throw new RuntimeException(自定义的异常);}return 10000;}}4.2.4、LogAspect
package org.star.aspect;import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.*;
import org.springframework.stereotype.Component;Slf4j
Component
Aspect // 生成代理对象
public class LogAspect {/*** 相同的切入点进行抽取*/Pointcut(value execution(* org.star.component.ATM.take(..)))public void commonPoint() {}/*** 前置通知方法执行之前执行*/// Before(value execution(* org.star.component.ATM.take(..)))// Before(value commonPoint())public void beforeLog() {log.info(前置通知执行...);}/*** 后置通知正常结束通知方法正常执行结束时才会通知出现异常不会执行*/// AfterReturning(value execution(* org.star.component.ATM.take(..)),returning result)// AfterReturning(value commonPoint(),returning result)public void afterReturningLog(Object result) {log.info(后置通知正常结束通知执行...返回值{},result);}// AfterThrowing(value execution(* org.star.component.ATM.take(..)),throwing ex)// AfterThrowing(value commonPoint(),throwing ex)public void afterThrowingLog(Exception ex) {log.info(异常通知目标方法出现异常时执行...异常信息{},ex.getMessage());}/*** 最终通知不管目标方法执行期间是否有异常都会执行* 思考目标方法正常执行结束控制台打印的日志如下* 07:55:40.702 [main] INFO org.star.aspect.LogAspect - 前置通知执行...* 07:55:40.717 [main] INFO org.star.component.ATM - 取钱方法正在执行...* 07:55:40.717 [main] INFO org.star.aspect.LogAspect - 最终通知不管目标方法执行期间是否有异常都会执行...* 07:55:40.717 [main] INFO org.star.aspect.LogAspect - 后置通知正常结束通知执行...返回值10000* 为什么最终通知先于后置通知执行* 答后置通知是在方法执行return后执行的是不可能修改方法的返回值的而最终通知是在目标方法返回前执行的即便目标方法出现抛出异常最终通知* 也会执行但当抛出异常时后置通知将不会执行。*/// After(value execution(* org.star.component.ATM.take(..)))// After(value commonPoint())public void afterLog() {log.info(最终通知不管目标方法执行期间是否有异常都会执行...);}/*** 环绕通知* param joinPoint* return*/// Around(value execution(* org.star.component.ATM.take(..)))Around(value commonPoint())public Object aroundLog(ProceedingJoinPoint joinPoint) {Object result null;try {log.info(around before);result joinPoint.proceed(); // 调用目标方法返回的值log.info(around afterReturning result:{},result);} catch (Throwable e) {log.info(around afterThrowing);} finally {log.info(around after);}return result;}}4.2.5、AppTest
package org.star;import lombok.extern.slf4j.Slf4j;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.star.component.ATM;
import org.star.config.MySpringConfig;/*** Unit test for simple App.*/
Slf4j
public class AppTest {public static void main(String[] args) {ApplicationContext context new AnnotationConfigApplicationContext(MySpringConfig.class);ATM atm context.getBean(ATM.class);log.info(atm:{},atm);if (atm ! null) {atm.take(1000);}}}4.3、基于自定义注解方式实现springboot
4.3.1、pom
dependenciesdependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-web/artifactId/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-test/artifactIdscopetest/scope/dependencydependencygroupIdorg.springframework.boot/groupIdartifactIdspring-boot-starter-aop/artifactId/dependencydependencygroupIdorg.projectlombok/groupIdartifactIdlombok/artifactIdoptionaltrue/optional/dependencydependencygroupIdorg.apache.commons/groupIdartifactIdcommons-collections4/artifactIdversion4.4/version/dependencydependencygroupIdorg.apache.commons/groupIdartifactIdcommons-lang3/artifactId/dependencydependencygroupIdcom.alibaba/groupIdartifactIdfastjson/artifactIdversion2.0.6/version/dependencydependencygroupIdcn.hutool/groupIdartifactIdhutool-all/artifactIdversion5.7.22/version/dependency/dependencies
4.3.2、LogAnnotation
package org.star.annotation;import java.lang.annotation.*;/*** Author: liuhaibo* Date: 2023/8/28 10:16* Description:*/
Target(ElementType.METHOD)
Retention(RetentionPolicy.RUNTIME)
Documented
public interface LogAnnotation {String value() default ;}4.3.3、UserVO
package org.star.entity.vo;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;import java.io.Serializable;/*** Author: liuhaibo* Date: 2023/8/28 10:22* Description:*/
Data
AllArgsConstructor
NoArgsConstructor
public class UserVO implements Serializable {/*** 编号*/private Integer id;/*** 姓名*/private String name;/*** 年龄*/private Integer age;}4.3.4、UserService
package org.star.service;import org.star.entity.vo.UserVO;import java.util.List;/*** Author : 一叶浮萍归大海* Date: 2023/8/28 7:55* Description:*/
public interface UserService {/*** 查询所有用户* return*/ListUserVO listAllUser();/*** 根据id查询用户* param id* return*/UserVO getUserById(Integer id);/*** 添加用户* param param* return*/boolean saveUser(UserVO param);/*** 修改用户* param param* return*/boolean editUser(UserVO param);/*** 根据id删除用户* param id* return*/boolean delUserById(Integer id);
}4.3.5、UserServiceImpl
package org.star.service.impl;import org.springframework.stereotype.Component;
import org.star.entity.vo.UserVO;
import org.star.service.UserService;import java.util.Arrays;
import java.util.List;/*** Author : 一叶浮萍归大海* Date: 2023/8/28 7:55* Description:*/
Component
public class UserServiceImpl implements UserService {Overridepublic ListUserVO listAllUser() {ListUserVO users Arrays.asList(new UserVO(1, 张三, 23),new UserVO(2, 李四, 24),new UserVO(3, 王五, 25));return users;}Overridepublic UserVO getUserById(Integer id) {return new UserVO(1, 张三, 23);}Overridepublic boolean saveUser(UserVO param) {return true;}Overridepublic boolean editUser(UserVO param) {return true;}Overridepublic boolean delUserById(Integer id) {return true;}
}4.3.6、UserController
package org.star.controller;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.star.annotation.LogAnnotation;
import org.star.entity.vo.UserVO;
import org.star.service.UserService;import java.util.List;/*** Author: liuhaibo* Date: 2023/8/28 10:19* Description:*/
RestController
RequestMapping(/user)
public class UserController {Autowiredprivate UserService userService;LogAnnotation(value 查询所有用户)GetMapping(/listAllUser)public ListUserVO listAllUser() {return userService.listAllUser();}GetMapping(/getUserById/{id})public UserVO getUserById(PathVariable(id) Integer id) {return userService.getUserById(id);}LogAnnotation(value 添加用户)PostMapping(/saveUser)public boolean saveUser(RequestBody UserVO param) {return userService.saveUser(param);}LogAnnotation(value 修改用户)PutMapping(/editUser)public boolean editUserById(RequestBody UserVO param) {return userService.editUser(param);}LogAnnotation(value 根据ID删除用户)DeleteMapping(/delUserById/{id})public boolean delUserById(PathVariable(id) Integer id) {return userService.delUserById(id);}}4.3.7、测试 启动服务在Postman中访问接口观察控制台的日志输出。
五、切入点表达式
5.1、概述
5.2、语法
execution([权限修饰符] [返回值类型] [简单类名/全类名] [方法名]([参数列表]))5.3、案例
表达式含义execution(* org.star.ArithmeticCalculator.*(..))1ArithmeticCalculator接口中声明的所有方法 2第一个*代表任意修饰符及任意返回值 3第二个*代表任意方法 4..代表匹配任意数量、任意类型的参数。若目标类、接口与该切面类在同一个包中可以省略包名。execution(public * ArithmeticCalculator.*(..))ArithmeticCalculator接口的所有公有方法execution(public double ArithmeticCalculator.*(..))ArithmeticCalculator接口中返回值类型为double的方法execution(public double ArithmeticCalculator.*(double,..))ArithmeticCalculator接口中第一个参数为double类型的方法。第二个参数..代表匹配任意数量、任意类型的参数execution(public double ArithmeticCalculator.*(double, double))ArithmeticCalculator接口中参数类型为doubledouble类型的方法 5.4 、高级应用 在AspectJ中切入点表达式还可以与逻辑运算符结合起来使用
# 任意类中第一个参数为int类型的add方法或sub方法
execution (* org.star.ArithmeticCalculator.add(int,..)) || execution(* org.star.ArithmeticCalculator.sub(int,..))# 匹配不是任意类中第一个参数为int类型的add方法
!execution (* org.star.ArithmeticCalculator.add(int,..)) 六、切面的优先级
6.1、概述 如果系统定义了多个切面如何让某些切面先运行可以通过设置切面的优先级来改变切面的执行顺序注解为Order(数字)其中数字越小优先级越高。
6.2、案例代码
6.2.1、pom
dependenciesdependencygroupIdcglib/groupIdartifactIdcglib/artifactIdversion3.1/version/dependencydependencygroupIdaopalliance/groupIdartifactIdaopalliance/artifactIdversion1.0/version/dependencydependencygroupIdorg.aspectj/groupIdartifactIdaspectjweaver/artifactIdversion1.9.19/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-aop/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdcommons-logging/groupIdartifactIdcommons-logging/artifactIdversion1.1.1/version/dependencydependencygroupIdcom.alibaba/groupIdartifactIddruid/artifactIdversion1.2.16/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-beans/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-context/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-core/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdorg.springframework/groupIdartifactIdspring-expression/artifactIdversion5.2.5.RELEASE/version/dependencydependencygroupIdjunit/groupIdartifactIdjunit/artifactIdversion4.13.2/version/dependencydependencygroupIdcom.alibaba/groupIdartifactIdfastjson/artifactIdversion1.2.76/version/dependency!-- 普通maven项目中使用Sl4j注解 --dependencygroupIdorg.projectlombok/groupIdartifactIdlombok/artifactIdversion1.18.22/version/dependencydependencygroupIdorg.slf4j/groupIdartifactIdslf4j-api/artifactIdversion1.7.32/version/dependencydependencygroupIdch.qos.logback/groupIdartifactIdlogback-classic/artifactIdversion1.2.10/version/dependency/dependencies
6.2.2、ATM
package org.star.component;import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;Slf4j
Component
public class ATM {public int take(int money) {log.info(取钱方法正在执行...);if (money 100) {throw new RuntimeException(自定义的异常);}return 10000;}}6.2.3、MySpringConfig
package org.star.config;import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;Configuration
ComponentScan(basePackages {org.star})
EnableAspectJAutoProxy(proxyTargetClass true) // 启用CGLB动态代理
public class MySpringConfig {}6.2.4、LogAspect
package org.star.aspect;import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.*;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;/*** Aspect : 生成代理类*/
Slf4j
Component
Aspect
Order(1)
public class LogAspect {/*** 相同的切入点进行抽取*/Pointcut(value execution(* org.star.component.ATM.take(..)))public void commonPoint() {}/*** 前置通知方法执行之前执行*/// Before(value execution(* org.star.component.ATM.take(..)))Before(value commonPoint())public void beforeLog() {log.info(log前置通知执行...);}/*** 后置通知正常结束通知方法正常执行结束时才会通知出现异常不会执行*/// AfterReturning(value execution(* org.star.component.ATM.take(..)),returning result)AfterReturning(value commonPoint(),returning result)public void afterReturningLog(Object result) {log.info(log后置通知正常结束通知执行...返回值{},result);}}6.2.5、ArgsAspect
package org.star.aspect;import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;/*** Aspect : 生成代理类*/
Slf4j
Component
Aspect
Order(2)
public class ArgsAspect {/*** 相同的切入点进行抽取*/Pointcut(value execution(* org.star.component.ATM.take(..)))public void commonPoint() {}/*** 前置通知方法执行之前执行*/// Before(value execution(* org.star.component.ATM.take(..)))Before(value commonPoint())public void beforeLog() {log.info(args前置通知执行...);}/*** 后置通知正常结束通知方法正常执行结束时才会通知出现异常不会执行*/// AfterReturning(value execution(* org.star.component.ATM.take(..)),returning result)AfterReturning(value commonPoint(),returning result)public void afterReturningLog(Object result) {log.info(args后置通知正常结束通知执行...返回值{},result);}}6.2.6、AppTest
package org.star;import lombok.extern.slf4j.Slf4j;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.star.component.ATM;
import org.star.config.MySpringConfig;/*** Unit test for simple App.*/
Slf4j
public class AppTest {public static void main(String[] args) {ApplicationContext context new AnnotationConfigApplicationContext(MySpringConfig.class);ATM atm context.getBean(ATM.class);log.info(atm:{},atm);if (atm ! null) {atm.take(1000);}}}// 控制台打印结果
15:39:18.209 [main] INFO org.star.AppTest - atm:org.star.component.ATM223aa2f7
15:39:18.213 [main] INFO org.star.aspect.LogAspect - log前置通知执行...
15:39:18.213 [main] INFO org.star.aspect.ArgsAspect - args前置通知执行...
15:39:18.224 [main] INFO org.star.component.ATM - 取钱方法正在执行...
15:39:18.224 [main] INFO org.star.aspect.ArgsAspect - args后置通知正常结束通知执行...返回值10000
15:39:18.224 [main] INFO org.star.aspect.LogAspect - log后置通知正常结束通知执行...返回值10000七、使用AOP注意事项
1连接点方法不能是private否则AOP不能进行增强
2连接点在其他方法内部被调用时不会被增强
