DWR 实现单向聊天【一：配置问题】 功能登录显示登录用户【无数据库操作】
开始准备工作一：
一：需导入开发包 commons-logging-1.0.4.jar 、log4j-1.2.11.jar 、dwr.jar

二：在web.xml 中配置如下：

<servlet>
 <servlet-name>dwr-invoke</servlet-name>
 <servlet-class> org.directwebremoting.servlet.DwrServlet
 </servlet-class>
 <init-param>
      <param-name>debug</param-name>
      <param-value>true</param-value>
 </init-param>
 <init-param>
      <param-name>activeReverseAjaxEnabled</param-name>
      <param-value>true</param-value>
 </init-param>
 <init-param>
 <param-name> org.directwebremoting.event.ScriptSessionListener    </param-name>
 <param-value> com.dwr.ScriptSessionListenerImpl </param-value>
 </init-param>
 <init-param>
    <param-name> * </param-name>
    <param-value>*</param-value>
 </init-param>
    <load-on-startup>0</load-on-startup>
 </servlet>
 <servlet>
    <description>This is the description of my J2EE component
    </description>
    <display-name>This is the display name of my J2EE component
    </display-name>
    <servlet-name>ExitGameServlet</servlet-name>
    <servlet-class>com.servlets.ExitGameServlet
    </servlet-class>
 </servlet>
 <servlet-mapping>
       <servlet-name>dwr-invoke</servlet-name>
       <url-pattern>/dwr/*</url-pattern>
 </servlet-mapping><servlet-mapping>
      <servlet-name>ExitGameServlet</servlet-name>
       <url-pattern>/ExitGameServlet</url-pattern>
 </servlet-mapping>