一，AOP
1，面向切面编程 Aspect Oriented Programming
2，编程思想的发展路程
① Logic java： java 逻辑编程
② OOP ： 面向对象编程
③ OIP ： interface 面向接口编程
④ 面向配置文件编程
以上的思想， 都是逐步升级的概念
⑤ AOP 在OOP的基础上，增强了OOP的功能
3， 实现方式
① 基于配置（xml）
② 基于注解
4、代码案例
（1）配置版
创建第一个类
package com.bh.dao;
import com.sun.xml.internal.ws.api.model.wsdl.WSDLOutput;
import org.springframework.stereotype.Repository;
public class EmpDAO {
public int save(){
System.out.println("保存了一条 emp 数据");
return 1;
}
}
创建第二个类
package com.bh.dao;
import org.springframework.stereotype.Repository;
public class DeptDAO {
public int save(){
System.out.println("保存了一条 dept 数据");
return 1;
}
public int remove(){
System.out.println("删除了 dept 的数据");
return 1;
}
}
创建增强类
package com.bh.aop;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.Signature;
import java.util.Date;
public class LogAdvice {
public int around(JoinPoint joinPoint) throws Throwable{
System.out.println("start=========" + new Date());
Integer signature = joinPoint.getSignature().getModifiers();
System.out.println("end=========" + new Date());
return signature;
}
}
配置applicationContext.xml文件
<?xml version="1.0" encoding="utf-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
">
<bean id="dept" class="com.bh.dao.DeptDAO"></bean>
<bean id="emp" class="com.bh.dao.EmpDAO"></bean>
<bean id="logadvice" class="com.bh.aop.LogAdvice"></bean>
<!--配置增强类-->
<aop:config>
<aop:aspect ref="logadvice">
<!--<aop:around method="around" pointcut="execution(* com.bh.dao.*.*(..))"></aop:around>-->
<!--execution(* com.bh.dao.*.*(..))为切入点表达式：表示要增强的方法-->
<aop:before method="around" pointcut="execution(* com.bh.dao.*.*(..))"></aop:before><!--before为前置增强-->
</aop:aspect>
</aop:config>
</beans>
测试类
package com.bh.test;
import com.bh.dao.DeptDAO;
import com.bh.dao.EmpDAO;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test {
public static void main(String[] args) {
ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
DeptDAO dept = (DeptDAO) ac.getBean("dept");
//dept.save();
//dept.remove();
EmpDAO emp = (EmpDAO) ac.getBean("emp");
emp.save();
}
}
结果
start=========Sat Jun 03 15:01:30 CST 2023
end=========Sat Jun 03 15:01:30 CST 2023
保存了一条 emp 数据
创建带注解的类
package com.bh.dao;
import com.sun.xml.internal.ws.api.model.wsdl.WSDLOutput;
import org.springframework.stereotype.Repository;
@Repository
public class EmpDAO {
public int save(){
System.out.println("保存了一条 emp 数据");
return 1;
}
}
创建带注解的类
package com.bh.dao;
import org.springframework.stereotype.Repository;
@Repository
public class DeptDAO {
public int save(){
System.out.println("保存了一条 dept 数据");
return 1;
}
public int remove(){
System.out.println("删除了 dept 的数据");
return 1;
}
}
创建带注解的切面增强类
package com.bh.aop;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.springframework.stereotype.Component;
import java.util.Date;
@Component
@Aspect//这个注解说明此类为切面类
public class LogAdvice1 {
//前置通知
/* @Before("execution(* com.bh.dao.*.*(..))")
public void before1(JoinPoint jp) {
System.out.println("method start =========" + new Date());
}*/
@Around("execution(* com.bh.dao.*.*(..))")//@Around表示环绕增强（其他同理）、execution(* com.bh.dao.*.*(..))切入点表达式
public int around(ProceedingJoinPoint proceedingJoinPoint) throws Throwable{
System.out.println("start=========" + new Date());
Integer proceed = (Integer) proceedingJoinPoint.proceed();
System.out.println("end=========" + new Date());
return proceed;
}
}
配置applicationAutoContext.xml文件
<?xml version="1.0" encoding="utf-8"?>
<beans
xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
">
<!--基于注解AOP：有效-->
<aop:aspectj-autoproxy/>
<!--开启spring扫描注解-->
<context:annotation-config></context:annotation-config>
<context:component-scan base-package="com.bh"></context:component-scan>
</beans>
测试类
package com.bh.test;
import com.bh.dao.DeptDAO;
import com.bh.dao.EmpDAO;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Test1 {
public static void main(String[] args) {
//读取配置文件
ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext("applicationAutoContext.xml");
//调用方法获得类实例
DeptDAO bean = ac.getBean(DeptDAO.class);
bean.save();
}
}
结果
start=========Sat Jun 03 15:10:16 CST 2023
保存了一条 dept 数据
end=========Sat Jun 03 15:10:16 CST 2023