spring实例化bean之构造方法实例化

PersonDao

public interface PersonDao {

}
PersonDaoImpl
public class PersonDaoImpl implements PersonDao{

public PersonDaoImpl(){
System.out.println("spring通过构造方法来实例化对象");
}
}

applicationContext.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"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"> <!-- spring通过构造方法创建PersonDaoImpl -->
<bean id="personDao" class="com.xxc.initBean.one.dao.Impl.PersonDaoImpl"></bean>
</beans>

测试类
public class App {
public static void main(String[] args) {
ApplicationContext ac = new ClassPathXmlApplicationContext("com/xxc/initBean/one/applicationContext.xml");
PersonDao personDao = (PersonDaoImpl)ac.getBean("personDao");
}
}