有个接口TestServiceInter,有两个实现方法TestService和Test2Service。他们都有sayHello();咱们的需求是在调用这两个方法以前,要先完成写日志的功能;html
我在各个实现类的sayHello()方法里面写上写日志的功能就是了。spring
package com.jdc.aop;/** * @author DEllComputer * @Title: TestService * @ProjectName SpringAop * @Description: * @date 2018/12/251:38 PM */public interface TestService { /** * @Description: * @param ${tags} * @return ${return_type} * @throws * @author jdc * @date 2018/12/25 1:39 PM */ void sayHi(String name); }
public class TestServiceImpl implements TestService { private String name; /** * @Description: say hi * @param ${tags} * @return ${return_type} * @throws * @author jdc * @date 2018/12/25 1:40 PM */ @Override public void sayHi(String name ) { System.out.println("hi:" + name); } public String getName() { return name; } public void setName(String name) { this.name = name; } }
/** * @author DEllComputer * @Title: MyBeforeAdvice * @ProjectName SpringAop * @Description: 写日志前置通知 * @date 2018/12/251:42 PM */public class MyBeforeAdvice implements MethodBeforeAdvice { /** * @Description: 写日志的功能 * @param ${tags} * @return ${return_type} * @throws * @author jdc * @date 2018/12/25 1:44 PM */ @Override public void before(Method method, Object[] objects, Object o) throws Throwable { System.out.println("我是写日志的功能。"); } }
前置通知须要实现MethodBeforeAdvice接口,前置通知是在目标方法调用以前调用;ide
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <!-- 配置前置通知 --> <bean id="myBeforeAdvice" class="com.jdc.aop.advice.MyBeforeAdvice"/> <!-- 配置被代理对象 --> <bean id="logTestServiceImpl" class="com.jdc.aop.TestServiceImpl"> <property name="name" value="Test"></property> </bean> <!-- 配置代理对象 --> <bean id="proxyFactoryBean" class="org.springframework.aop.framework.ProxyFactoryBean"> <!-- 代理接口集 配置哪些接口要被代理 --> <property name="proxyInterfaces"> <list> <value>com.jdc.aop.TestService</value> </list> </property> <!-- 把通知织入代理对象 --> <property name="interceptorNames"> <value>myBeforeAdvice</value> </property> <!-- 配置被代理的对象 --> <property name="target" ref="logTestServiceImpl"/> </bean> </beans>
ProxyFactoryBean是一个代理对象,若是咱们被代理的对象实现了接口,Spring使用的是jdk动态代理技术实现的动态代理;因此咱们要告诉代理对象,咱们的哪 些接口须要被代理,而后哪一个对象须要被代理,个人加强实现应该怎么被织入到代理对象(前置,后置,环绕....)
public class TestMain { public static void main(String[] args) { ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml"); //获取代理对象 TestService log = (TestService) ac.getBean("proxyFactoryBean"); log.sayHi("哈哈"); } }
注意这里,咱们须要获取代理对象,而不是目标对象,否则不能调用前置通知的代码。测试