spring AOP详解之--前置增强 （MethodBeforeAdvice）

这里举一个简单的demo

先写一个接口 Hello.java

package niit.soft1521;/** * Created by lenovo-pc on 2017/3/13. */public interface Hello {     String sayHello();}

在写一个接口的实施类HelloImpl.java

package niit.soft1521;/** * Created by lenovo-pc on 2017/3/13. */public class HelloImpl implements Hello {    @Override    public String sayHello() {       return "hello ,welcom !";    }}

再写一个前置增强的类MyBeforeMethod.java

package niit.soft1521;/** * Created by lenovo-pc on 2017/3/13. * 用户自定义的前置增强类 */public class MybeforeMethod {    public void BeforeMethod(){        System.out.println("this is a before method !");    }}

最后的xml文件的配置

<?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"       xsi:schemaLocation="http://www.springframework.org/schema/beans        http://www.springframework.org/schema/beans/spring-beans.xsd        http://www.springframework.org/schema/aop        http://www.springframework.org/schema/aop/spring-aop.xsd">    <bean id="hello" class="niit.soft1521.HelloImpl"></bean>    <bean id="MyBefore" class="niit.soft1521.MybeforeMethod"></bean>    <aop:config>            <aop:aspect id="before" ref="MyBefore">                <aop:pointcut id="MyPointCut" expression="execution(* niit.soft1521.*.*(..))"></aop:pointcut>                <aop:before method="BeforeMethod" pointcut-ref="MyPointCut"></aop:before>            </aop:aspect>    </aop:config></beans>

再编写一个测试类TestHello.java

package niit.soft1521;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;/** * Created by lenovo-pc on 2017/3/13. */public class TestHello {    public static void main(String[] args) {        ApplicationContext applicationContext =new ClassPathXmlApplicationContext("ApplicationContext.xml");        Hello hello=(Hello)applicationContext.getBean("hello");        System.out.println(hello.sayHello());    }}

这就是一个完整的前置增强的例子，后面我还会陆续介绍其他几种增强。谢谢