AOP的MethodBeforeAdvice

使用Spring自动生成代理类,spring利用的是动态代理机制
接口

public interface UserDao {
 void addUser();
 void deleteUser();
}

 
两个实现:

public class UserDaoMySqlImpl implements UserDao {

 @Override
 public void addUser() {
  System.out.println("UserDaoMySqlImpl.addUser()");
 }

 @Override
 public void deleteUser() {
  System.out.println("UserDaoMySqlImpl.deleteUser()");

 }

}
public class UserDaoOracleImpl implements UserDao {

 @Override
 public void addUser() {
  System.out.println("UserDaoOracleImpl.addUser()");
 }

 @Override
 public void deleteUser() {
  System.out.println("UserDaoOracleImpl.deleteUser()");
 }

}
Device
import java.lang.reflect.Method;

import org.springframework.aop.MethodBeforeAdvice;

public class UserDaoBeforeAdvice implements MethodBeforeAdvice {

 @Override
 public void before(Method arg0, Object[] arg1, Object arg2)
   throws Throwable {
  System.out.println("UserDaoBeforeAdvice.before()");
 }

}

 spring的配置文件

<!-- 配置实现类的bean,可以把所有的实现类都写上 -->
<bean id="userdao" class="com.dowebber.spring.aop.UserDaoMySqlImpl"></bean>
<!--配置Advice的bean -->
<bean id="beforeadvice" class="com.dowebber.spring.aop.UserDaoBeforeAdvice"></bean>
<!--配置spring自动生成代理对象所需要的一些参数 -->
<bean id="userdaoproxy" class="org.springframework.aop.framework.ProxyFactoryBean">
 <property name="proxyInterfaces" value="com.dowebber.spring.aop.UserDao"/>
 <property name="target">
  <ref bean="userdao"/>
 </property>
 <property name="interceptorNames">
  <list>
   <value>beforeadvice</value>
  </list>
 </property>
</bean>

 测试类:

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestUserDaoBeforeDevice {

 public static void main(String[] args) {
  
  ApplicationContext context = new ClassPathXmlApplicationContext("com/dowebber/spring/aop/spring.xml");
  UserDao dao = (UserDao)context.getBean("userdaoproxy");
  dao.addUser();
 }

}