知道JSP页面里使用${}的来

我想知道下面红色部分的作用
请详细说明${}的使用方法
<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<%@ taglib uri="http://struts.apache.org/tags-logic" prefix="logic" %>
<%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>公司介绍/${newsClassName }</title>
<body>
<table class="main" width="1003" border="0" align="center" cellpadding="0" cellspacing="0">
  <tr>
    <td align="center" valign="top"><%@include file="/top.jsp"%></td>
  </tr>
  <tr>
    <td align="center" valign="top"><table width="865" border="0" cellspacing="0" cellpadding="0">
      <tr>
        <td valign="top"><table border="0" cellspacing="0" cellpadding="0">
          <tr>
            <td width="202" align="center" valign="top" bgcolor="#FFFFFF"><table width="100%" border="0" cellpadding="0" cellspacing="0" bgcolor="#FFFFFF">
              <tr>
                <td align="right" valign="top"><img src="/images/about_right.gif" width="10" height="10" /></td>
              </tr>
              <tr>
                <td align="right" valign="top" bgcolor="#FFFFFF"><table width="100%" border="0" cellspacing="0" cellpadding="0">
                  <tr>
                    <td height="95" align="center" valign="top"><img src="/images/about_.jpg" width="190" height="85" /></td>
                  </tr>
                  <tr>
                    <td valign="top">
                    
                    
                      <logic:present name="newsClass">
             <logic:iterate id="n" name="newsClass" property="childNewsClasses">
                    <table width="100%" border="0" cellspacing="0" cellpadding="0">
                      <tr>
                        <td height="30" align="right" valign="middle" class="menu"><a href="/articleView/company/010805/${n.flag}/${n.id}.html">${n.name}</a>&nbsp;&nbsp;</td>
                      </tr>
                      <tr>
                        <td align="right" valign="middle"><img src="/images/about_01.gif" width="180" height="13" /></td>
                      </tr>
                    </table>
                 </logic:iterate>
         </logic:present>      
                    </td>
                  </tr>
                </table></td>
              </tr>
            </table></td>
            <td width="3"></td>
            <td width="660" align="left" valign="top" bgcolor="#FFFFFF"><table width="100%" border="0" align="center" cellpadding="0" cellspacing="0">
              <tr>
                <td class="img" width="600" height="195" align="left" valign="top"><img src="/images/about.jpg" width="651" height="187" /></td>
              </tr>
              <tr>
                <td class="content" valign="top">${article.content}</td>
              </tr>
            </table></td>
          </tr>
        </table></td>
      </tr>
      
      <tr>
        <td valign="top"><img src="/images/bgbbottom_01.gif" width="865" height="21" /></td>
      </tr>
    </table></td>
  </tr>
  <tr>
    <td align="center" valign="top"><%@include file="/bottom.jsp"%></td>
  </tr>
</table>
</body>
</html>

解决方案 »

  1.   

    ${newsClassName }  在session 或request 里面取得 键值为newsClassName  的对象并转换为字符串${n.id} 在session 或request 里面取得 键值为 n的对象，并获取它的id属性，实际上是调用getId（）方法获取
      

  2.   

    我资源里有本el详细介绍.chm
    介绍的很详细，配有大量代码示例
    楼主可以去看看
      

  3.   

    依次在page、request、session、application中查找名为newsClassName的值