构造注入

 1 private IUserDao dao;
 2     
 3     public IUserBizImpl() {
 4         super();
 5         // TODO Auto-generated constructor stub
 6     }
 7     public IUserBizImpl(IUserDao dao) {
 8     super();
 9     this.dao = dao;
10     }

<bean id="mydao" class="com.dao.impl.IUserDaoImpl"></bean>
    <bean id="biz" class="com.biz.impl.IUserBizImpl">
        <!-- 构造方法 -->
        <constructor-arg>
        <ref bean="mydao"/>
        </constructor-arg>
    
    </bean>