JAVA 框架-Spring-AOP面向切面

AOP（Aspect Orient Programming），我們一般稱為面向方面（切面）編程，作為面向對象的一種補充，用于處理系統中分布于各個模塊的橫切關注點，比如事務管理、日志、緩存等等。AOP實現的關鍵在于AOP框架自動創建的AOP代理，AOP代理主要分為靜態代理和動態代理，靜態代理的代表為AspectJ；而動態代理則以Spring AOP為代表。

AOP配置示例：

需要的包：aspectjweaver-1.8.4.jar

數據訪問層：

package com.hanqi.dao;public class AppuserDao {public int deleteUser(int ids) {System.out.println(ids +"被刪除");yichang();//拋出一個異常return 1;}public void yichang() {throw new RuntimeException("出現錯誤！");}
}

?切面代理層：

package com.hanqi.util;public class LogginProxy {public void beforeMethod() {System.out.println("方法之前被調用！");}public void afterMethod() {System.out.println("方法之后被調用！");}public void returnMethod() {System.out.println("返回結果時被調用！");}public void throwMethod() {System.out.println("拋出異常時被調用！");}/*public void aroundMethod() {System.out.println("方法被調用");}*/
}

?spring.xml配置AOP

?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:aop="http://www.springframework.org/schema/aop"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd"><bean id="logginProxy" class="com.hanqi.util.LogginProxy"></bean><bean id="appuserdao" class="com.hanqi.dao.AppuserDao"></bean><aop:config><!-- 配置切點 --><aop:pointcutexpression="execution(* com.hanqi.dao.*.*(..))" id="aoppointcut" /><!--execution:執行，這句意為在執行com.hanqi.dao下的所有類時都會執行切面類--><!-- 指明切面類 --><aop:aspect ref="logginProxy"><aop:before method="beforeMethod"  pointcut-ref="aoppointcut"/><aop:after method="afterMethod" pointcut-ref="aoppointcut"/><aop:after-returning method="returnMethod" pointcut-ref="aoppointcut"/><aop:after-throwing method="throwMethod" pointcut-ref="aoppointcut"/>	</aop:aspect></aop:config>
</beans>

?JUnit Test測試：

package com.hanqi.util;import static org.junit.jupiter.api.Assertions.*;import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;import com.hanqi.dao.AppuserDao;class JUnittest {private ClassPathXmlApplicationContext c;private AppuserDao appuserdao;@BeforeEachvoid setUp() throws Exception {c = new ClassPathXmlApplicationContext("spring.xml");appuserdao = c.getBean(AppuserDao.class);}@AfterEachvoid tearDown() throws Exception {c.close();}@Testvoid test() {appuserdao.deleteUser(55);}}

?打印結果：

使用注解配置AOP

spring.xml配置：

<?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:aop="http://www.springframework.org/schema/aop"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.3.xsd"><context:component-scan base-package="com.hanqi"></context:component-scan><!--配置掃描器-->
</beans>

數據訪問層：

package com.hanqi.dao;import org.springframework.stereotype.Repository;@Repository//加到spring容器中，id名默認為類名首字母小寫
public class AppuserDao {public int deleteUser(int ids) {System.out.println(ids +"被刪除");yichang();return 1;}public void yichang() {throw new RuntimeException("出現錯誤！");}
}

?AppuserService類：

package com.hanqi.service;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Repository;import com.hanqi.dao.AppuserDao;
@Repository
public class AppuserService {@Autowired//從spring容器中將該類自動放到當前類中的成員變量中，默認的裝配類型時byType//@Qualifier("dao")該注解可將bean中id="dao"的類裝配到該成員變量中，用于區分當類型相同時；private AppuserDao appuserDao;public int deleteUser(int ids) {return appuserDao.deleteUser(ids);}
}

?代理類：

package com.hanqi.util;import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.AfterThrowing;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import org.springframework.stereotype.Repository;@Repository//加到spring容器中，id名為類名首字母小寫
@Aspect//聲明當前類為切面類
@EnableAspectJAutoProxy//自動代理
public class LogginProxy {@Before("execution(* com.hanqi.dao.*.*(..))")//聲明切點public void beforeMethod() {System.out.println("方法之前被調用！");}@After("execution(* com.hanqi.dao.*.*(..))")public void afterMethod() {System.out.println("方法之后被調用！");}@AfterReturning("execution(* com.hanqi.dao.*.*(..))")public void returnMethod() {System.out.println("返回結果時被調用！");}@AfterThrowing("execution(* com.hanqi.dao.*.*(..))")public void throwMethod() {System.out.println("拋出異常時被調用！");}/*public void aroundMethod() {System.out.println("方法被調用");}*/
}

?測試類：

package com.hanqi.util;import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;import com.hanqi.dao.AppuserDao;
import com.hanqi.service.AppuserService;class JUnittest {private ClassPathXmlApplicationContext c;private AppuserDao appuserdao;private AppuserService appuserService;@BeforeEachvoid setUp() throws Exception {c = new ClassPathXmlApplicationContext("spring.xml");//appuserdao = c.getBean(AppuserDao.class);appuserService = c.getBean(AppuserService.class);}@AfterEachvoid tearDown() throws Exception {c.close();}@Testvoid test() {//appuserdao.deleteUser(55);appuserService.deleteUser(66);}}

?