Struts2学习笔记（3）

五、Struts2请求扩展名问题

配置Struts2可以受理请求的扩展名

<constantname=”struts.action.extension” value=”action,do,…”></constant>

可以通过设置value里面的值来配置。Struts2默认的扩展名是action。

六、struts2示例代码

登录->统计线人数(登录用户名)->退出减少在线人数（只实现功能，未考虑过多逻辑问题）

Struts配置：

<struts>

      <constantname="struts.action.extension"value="action,do,"></constant>

      <package name="login"extends="struts-default">

           <action name="login">

                 <result>/login.jsp</result>

           </action>

          

           <action name="userlogin"class="com.yaorange.struts.userlogin.UserLoginAction">

                 <resultname="success">/loginSuccess.jsp</result>

           </action>

          

           <action name="loginOut"class="com.yaorange.struts.userlogin.UserLoginAction"

           method="loginOut">

                 <resultname="loginOut">/loginSuccess.jsp</result>

           </action>

      </package>

 

</struts>

首页：

<ahref="login.do">登录页面</a>

登录页面：

      <formaction="userlogin.do">

           username:<inputtype="text" name="username"/>

           <br>

           password:<inputtype="password" name="password"/>

           <br>

           <input type="submit"value="登录"/>

      </form>

Action类：

public classUserLoginAction implements SessionAware,ApplicationAware{

      private Map<String, Object>application;

      private Map<String, Object> session;

      private String username;

      private String password;

      public void setUsername(String username) {

           this.username = username;

      }

 

      public void setPassword(String password) {

           this.password = password;

      }

 

      public String execute(){

           //获取session

           //username和password的值是通过Action类中set方法注入

           session.put("username",username);

           session.put("password",password);

           System.out.println("username:"+username+"password:"+password);

           //获取在线总数

           Integer counts =(Integer)application.get("counts");

           //登录后判断counts是否为空，不为空加1，为空置为1

           if(counts!=null){

                 counts++;

           }else{

                 counts=1;

           }

           //再将counts放回

           application.put("counts",counts);

           return "success";

      }

     

      @Override

      public void setApplication(Map<String,Object> application) {

           this.application=application;

      }

 

      @Override

      public void setSession(Map<String,Object> session) {

           this.session=session;

      }

     

      public String loginOut(){

           Integer counts =(Integer)application.get("counts");

           //判断counts是否为空并且大于零，成立减一

           if(counts!=null &&counts>0){

                 counts--;

                 application.put("counts",counts);

           }

           //清空session

           ((SessionMap)session).invalidate();

           return "loginOut";

      }

     

     

}

成功页面：

      <h3>登录成功</h3>

      <br>

      欢迎用户：${sessionScope.username}

      <br>

      在线人数：${applicationScope.counts}

      <br>

      <a href="loginOut">退出登录</a>