基于DWR框架的验证用户名是否存在的Ajax应用
[url]
http://hi.baidu.com/homefovever/blog/item/49d1f900c49e4782e850cd38.html[/url]

PersonDAO.java

<servlet>    <servlet-name>dwr-invoker</servlet-name>    <servlet-class>      org.directwebremoting.servlet.DwrServlet    </servlet-class>    <init-param>      <param-name>debug</param-name>      <param-value>true</param-value>    </init-param>  </servlet>  <servlet-mapping>    <servlet-name>dwr-invoker</servlet-name>    <url-pattern>/dwr/*</url-pattern>  </servlet-mapping>