logic:equal,logic:present用法

logic:equal,logic:present用法

1.

<logic:equal value="a" name="documentContent">顯示</logic:equal>

 

<logic:equal name="DeliverProveForm" property="userAction" value="create">

如果DeliverProveForm裡的屬性userAction的值等於create就執行這兒。

</logic:equal>

2. <logic:present name="tipmsg"> 如果在你的action中設定了tipmsg就執行到這兒。如：request.setAttribute("tipmsg","提示資訊") 或session.setAttribute("tipmsg","提示資訊") <bean:write name="tipmsg"/> </logic:present>

 

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標籤<logic:present>的使用

request.getSession().setAttribute("pageBean", pageBean);

request.setAttribute("result", pageBean.getObjList());

 

在jsp中：

<logic:present name="result">        

<logic:iterate id="book" name="result">             

<logic:present name="book">               

   <tr>                    

  <td><bean:write name="book" property="name" /></td>                     

<td><bean:write name="book" property="author" /></td>                     

<td><bean:write name="book" property="price" /></td>                  

</tr>              

</logic:present>         

</logic:iterate>

</logic:present>

<logic:present name="result" scope="session">

這裡有個scope屬性可能是request,session等, name指的是一個對象,可能是javaBean,也可能是集合的對象,整個意思就是就是在scope(session,request) 範圍裡面尋找name(一個對象)是否存在,相當於一個if()語句.