spring_生命周期

<?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">

  <bean id="userDaoImpl" class="com.bjsxd.dao.impl.UserDaoImpl">
  </bean>
  
  <bean id="userService" class="com.bjsxd.service.UserService" init-method="init" destroy-method="destroy">
    <constructor-arg>
      <ref bean="userDaoImpl"/>
    </constructor-arg>
  </bean>
</beans>