<!--构造器注入 -->

   <bean id="user1" class="cn.happy.entity.User">

      <constructor-arg index="0" type="java.lang.String" value="lxl"></constructor-arg>

      <constructor-arg index="1" type="java.lang.String" value="lxl@163.com"></constructor-arg>

   </bean>

Test：
ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");

        User user=(User)ctx.getBean("user1");

        System.out.println(user.getEmail());

<!-- set方法注入 -->

   <bean id="user2" class="cn.happy.entity.User">

      <!-- 使用property -->

      <property name="username" value="张靓颖"></property>

   </bean>