在servlet中或者在filter中获取spring容器中的bean

1 配置spring文件

<bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate"> 
   <property name="sessionFactory" ref="sessionFactory"></property>
 </bean> 
 <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
   <property name="dataSource" ref="dataSource" />
 </bean>

2 在web.xml中加载spring的配置文件

<context-param>
  <param-name>contextConfigLocation</param-name>
  <param-value>
   classpath*:/spring/applicationContext_*.xml
  </param-value>
 </context-param>

3 在servlet中获取名字为jdbcTemplat的bean.

public class UserAuthorizationFilter extends HttpServlet {

private WebApplicationContext wac;

    public void init(){
        方法一：wac =WebApplicationContextUtils.getRequiredWebApplicationContext(

             this.getServletContext());

        方法二：wac = WebApplicationContextUtils.getWebApplicationContext(
          this.getServletContext());

       方法一和方法二得到的结果是一样的。

     //wac的类型：org.springframework.web.context.support.XmlWebApplicationContext

    }

public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {

     JdbcTemplate jdbcTemplate = (JdbcTemplate)wac.getBean("jdbcTemplate");

     String sql="select count(*) from customer where name='liwj' and password='1111111'";

     int num=jdbcTemplate.queryForInt(sql);
     if(num==1){