一、AOP
AOP(Aspect Oriented Programming)：面向切面编程，在OOP（Object Oriented Programming）中，关键单元模块度是类，而在AOP中单元模块度是方面。
应用场景：拦截器、声明式事物、日志等。
二、基于XML
【示例】
package com.my; /** * @Author jyy * @Description {} * @Date 2018/7/16 11:29 */ public class Person { private String id; private String name; private Address address; public Person() { } public Person(Address address) { this.address = address; } public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Address getAddress() { return address; } public void setAddress(Address address) { this.address = address; } public void getAddressDetail() { System.out.println("查询用户详细地址"); } }
package com.my; /** * @Author jyy * @Description {} * @Date 2018/8/6 11:28 */ public class AopTest { public void beforeAop() { System.out.println("======before aop======"); } public void afterAop() { System.out.println("======after aop======"); } }
package com.my; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; /** * @Author jyy * @Description {} * @Date 2018/7/13 10:06 */ public class MainApp { public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext("Beans.xml"); Person person = ctx.getBean(Person.class); person.getAddressDetail(); } }
<?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-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd "> <aop:config> <aop:aspect id="aop" ref="aopTest"> <aop:pointcut id="selectAll" expression="execution(* com.my.*.*(..))"/> <aop:before pointcut-ref="selectAll" method="beforeAop"/> <aop:after pointcut-ref="selectAll" method="afterAop"/> </aop:aspect> </aop:config> <bean id="person" class="com.my.Person"> <property name="id" value="1001"/> <property name="name" value="张三"/> <property name="address" ref="address"/> </bean> <bean id="address" class="com.my.Address"> <property name="country" value="中国"/> <property name="province" value="江苏省"/> <property name="city" value="南京市"/> </bean> <bean id="aopTest" class="com.my.AopTest"/> </beans>
输出结果：
======before aop======
查询用户详细地址
======after aop======
上面的示例是对切面的一个简单演示，我们主要分析下配置文件：
<aop:aspect id="aop" ref="aopTest"> 定义切面aop，指向类AopTest
<aop:pointcut id="selectAll" expression="execution(* com.my.*.*(..))"/> 定义切面的切点selectAll,指定切面的作用范围
<aop:before pointcut-ref="selectAll" method="beforeAop"/> 定义方法执行前操作，包括before、after、afterReturning、afterThrowing、around
<aop:after pointcut-ref="selectAll" method="afterAop"/> 定义方法执行后操作，包括before、after、afterReturning、afterThrowing、around
以上只是部分配置，其他配置自行查找
三、基于@AspectJ
开启@AspectJ支持
<aop:aspectj-autoproxy/>
【示例】
package com.my; /** * @Author jyy * @Description {} * @Date 2018/7/16 11:29 */ public class Person { private String id; private String name; private Address address; public Person() { } public Person(Address address) { this.address = address; } public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Address getAddress() { return address; } public void setAddress(Address address) { this.address = address; } public void getAddressDetail() { System.out.println("查询用户详细地址"); } }
package com.my; import org.aspectj.lang.annotation.After; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.annotation.Before; import org.aspectj.lang.annotation.Pointcut; /** * @Author jyy * @Description {} * @Date 2018/8/6 11:28 */ @Aspect public class AopTest { @Pointcut("execution(* com.my.*.*(..))") private void aopTest() {} @Before("aopTest()") public void beforeAop() { System.out.println("======before aop======"); } @After("aopTest()") public void afterAop() { System.out.println("======after aop======"); } }
package com.my; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; /** * @Author jyy * @Description {} * @Date 2018/7/13 10:06 */ public class MainApp { public static void main(String[] args) { ApplicationContext ctx = new ClassPathXmlApplicationContext("Beans.xml"); Person person = ctx.getBean(Person.class); person.getAddressDetail(); } }
<?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-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd "> <aop:aspectj-autoproxy/> <bean id="person" class="com.my.Person"> <property name="id" value="1001"/> <property name="name" value="张三"/> <property name="address" ref="address"/> </bean> <bean id="address" class="com.my.Address"> <property name="country" value="中国"/> <property name="province" value="江苏省"/> <property name="city" value="南京市"/> </bean> <bean id="aopTest" class="com.my.AopTest"/> </beans>
输出结果：
======before aop======
查询用户详细地址
======after aop======
当调用com.my.包路径下的所有方法时，都会在调用方法之前调用beforeAop()方法，在这里我们可以进行权限验证，实现拦截器的作用。