一、AOP是OOP的延续,是(Aspect Oriented Programming)的缩写,意思是面向切面编程。
AOP(Aspect Orient Programming),作为面向对象编程的一种补充,广泛应用于处理一些具有横切性质的系统级服务,
如事务管理、安全检查、缓存、对象池管理等。 AOP 实现的关键就在于 AOP 框架自动创建的 AOP 代理,
AOP 代理则可分为静态代理和动态代理两大类,其中静态代理是指使用 AOP 框架提供的命令进行编译,
从而在编译阶段就可生成 AOP 代理类,因此也称为编译时增强;
而动态代理则在运行时借助于 JDK 动态代理、CGLIB 等在内存中"临时"生成 AOP 动态代理类,因此也被称为运行时增强
AOP 的实现:
MyInterceptor、MyInterceptor2分别是以annotations和xml定义的切面类
package com.service;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
@Aspect
public class MyInterceptor {
@Pointcut("execution (* com.serviceImpl.PersonServiceImpl.*(..))")
private void myMethod(){};
@Before("myMethod()")
public void doAccessCheck(){
System.out.println("before");
}
}
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package com.service;
public class MyInterceptor2 {
public void doAccessCheck(){
System.out.println("before");
}
}
业务和接口
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package com.service;
public interface PersonService {
public void save(String name);
public void update(String name);
}
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package com.serviceImpl;
import com.service.PersonService;
public class PersonServiceImpl implements PersonService {
@Override
public void save(String name) {
// TODO Auto-generated method stub
System.out.println("保存");
}
@Override
public void update(String name) {
// TODO Auto-generated method stub
System.out.println("修改");
}
}
简单做个方法前通知,其他的都一样。
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<?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"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">
<aop:aspectj-autoproxy/>
<bean id="personServiceImpl" class="com.serviceImpl.PersonServiceImpl"></bean>
<bean id="personInterceptor" class="com.service.MyInterceptor2"></bean>
<aop:config>
<aop:aspect id="asp" ref="personInterceptor">
<aop:pointcut id="myCut" expression="execution (* com.serviceImpl.PersonServiceImpl.*(..))"/>
<aop:before pointcut-ref="myCut" method="doAccessCheck"/>
</aop:aspect>
</aop:config>
</beans>
测试类
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package com.test;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.service.PersonService;
public class AopTest {
@Test
public void interceptorTest(){
ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
PersonService ps = (PersonService) ac.getBean("personServiceImpl");
ps.save("aa");
}
}