Aspect(切面): 通常是一个类,里面可以定义切入点和通知。
Join point(连接点):程序执行过程中明确的点,一般是方法的调用。
Advice(通知):around执行前后,Before advice 在连接点之前执行,
Pointcut(切入点): 带有通知的连接点,在程序中主要体现为书写切入点表达式。
实例一(基于java注解配置的)
依赖jar包:spring-aop-4.1.6.RELEASE.jar,aspectjweaver-1.6.12.jar,cglib-2.2.jar,aopalliance-1.0.jar
1、编写切面类
package spring.aspect;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;
@Component //添加spring扫描bean注解
@Aspect // 设置该类为切面
public class AspectExamle {
@Before("execution(* spring.annotations.repository.UserRepository.*(..))") //设置通知点
public void doAccessCheck() {
// ...
System.out.println("Before check");
}
//@Pointcut("execution(* spring.annotations.repository.UserRepository.*(..))") //设置切点和连接面
@Pointcut("execution(public * *(..))")
private void anyPublicOperation() {
// ...
System.out.println("Before check");
}
}
2、在java的配置文件中开启EnableAspectJAutoProxy动态代理配置,扫描切面包
package spring.javabase;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
@Configuration
@ComponentScan(basePackages = {"spring.annotations","spring.aspect"})
@EnableAspectJAutoProxy
public class ScanAppConfig {
}
3、测试AOP是否生效
package spring.javabase;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import spring.HelloWorld;
import spring.annotations.controller.UserController;
public class JavaBaseContainer {
public static void main(String[] args) {
// TODO Auto-generated method stub
ApplicationContext ctx = new AnnotationConfigApplicationContext(AppConfig.class,ScanAppConfig.class);
HelloWorld helloWorld = ctx.getBean(HelloWorld.class);
helloWorld.setMessage("Hello World");
helloWorld.getMessage();
UserController controler = (UserController) ctx.getBean("userController");
controler.execute();
}
}
实例二: 基于xml 配置的aop
1、编写切面
package spring.aspect;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;
@Component
public class AspectExamleByXml {
//@Before("execution(* spring.annotations.repository.UserRepository.*(..))")
//@Before("anyPublicOperation()")
public void doAccessCheck() {
// ...
System.out.println("Before check");
}
//@Pointcut("execution(* spring.annotations.repository.UserRepository.*(..))")
//@Pointcut("within(spring.annotations.repository.*)")
//@Pointcut("execution(public * *(..))")
private void anyPublicOperation() {
// ...
System.out.println("Before check");
}
}
2、配置xml文件
<?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:context="http://www.springframework.org/schema/context"
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/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
<!-- <bean id="helloWorld" class="spring.HelloWorld">
<property name="message" value="Hello World!"/>
</bean>-->
<context:component-scan base-package="spring.annotations,spring.aspect"></context:component-scan>
<bean id="helloWorld" class="spring.HelloWorld">
<property name="message" value="Hello World!"/>
</bean>
<aop:config>
<aop:aspect ref="aspectExamleByXml"> <!-- 配置切面 -->
<aop:pointcut expression="execution(* spring.annotations.repository.UserRepository.*(..))" id="pointCut"/><!-- 配置切点和连接点 -->
<aop:before pointcut-ref="pointCut" method="doAccessCheck"/><!-- 配置通知 -->
</aop:aspect>
</aop:config>
</beans>