Spring基础之AOP和execultion表达式

AOP和execultion表达式
1、AOP相关名词

2、AOP通知类型

1）xml方式的通知类型

a.前置通知实现步骤：
1.导入jar包

2.编写实现类和spring上下文配置文件


HelloWorld.java

package njpji.server;
public class HelloWorld {
	public void print() {
		System.out.println("hello world...");
	}
	public void print2() {
		System.out.println("welcome to beijing...");
	}
}

NoticeBefore.java

package njpji.server;
import java.lang.reflect.Method;
import org.springframework.aop.MethodBeforeAdvice;
public class NoticeBefore implements MethodBeforeAdvice{
	//编写一个前置通知的方法
	@Override
	public void before(Method arg0, Object[] arg1, Object arg2) throws Throwable {
		System.out.println("您好，这是前置通知");
	}
}

beans.xml

<?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-4.3.xsd">

	<!-- 配置前置通知:关联方法 -->
	
	<!-- print()方法所在类 -->
	<bean id="helloWorld" class="njpji.server.HelloWorld"></bean>
	
	<!-- before()方法所在类 -->
	<bean id="noticeBefore" class="njpji.server.NoticeBefore"></bean>
	
	<!-- 将前置通知和print()方法进行关联 -->
	<aop:config>
		<!-- 配置切入点 -->
		<aop:pointcut expression="execution(public void njpji.server.HelloWorld.print2()) or execution(public void njpji.server.HelloWorld.print())" id="pointCut"/>
		<!-- advisor：相当于连接 "切入点" 和 "通知" 的桥梁 -->
		<aop:advisor advice-ref="noticeBefore" pointcut-ref="pointCut"/>
	</aop:config>
</beans>

Test.java

package njpji.test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import njpji.server.HelloWorld;
public class Test {
	public static void main(String[] args) {
		//加载spring上下文配置文件
		ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
		HelloWorld helloWorld = (HelloWorld) context.getBean("helloWorld");
		//打印输出：hello World...
		helloWorld.print();
		helloWorld.print2();
	}
}

2）运行截图

总结：另外"后置通知"、“异常通知”、"环绕通知"请各位自行琢磨…