struts.xml

<struts>
	<package name="default" namespace="/" extends="struts-default" strict-method-invocation="false">	
	<global-allowed-methods>regex:.*</global-allowed-methods>	
	</package>	
	<package name="users" namespace="/users" extends="default">	
		<action name="*_*" class="action.{1}Action" method="{2}">		
			<result name="login_success">/users/Users_login_success.jsp</result>	
			<result name="login_failure">/users/Users_login.jsp</result>		
			<result name="logout_success">/users/Users_login.jsp</result>	
			<result name="input">/users/Users_login.jsp</result>	
		</action>
				
	</package>
	<package name="students" namespace="/students"  extends="default">	
		<action name="*_*" class="action.{1}Action" method="{2}">	
			<result name="query_success">/students/Students_query_success.jsp</result>	
			<result name="delete_success" type="chain">Students_query</result>
			<result name="add_success">/students/Students_add_success.jsp</result>	
			<result name="modify_success">/students/Students_modify.jsp</result>
			
		</action>	
	</package>
</struts>

action

// 修改学生信息	
public String modify()  {	
	// 获得传过来的学生id	
		String sid = request.getParameter("sid");
		StudentsDAO sdao = new StudentsDAOimpl();	
		Students s = sdao.queryStudentsBySid(sid);		
		// 保存在session中		
		session.setAttribute("modify_students", s);
		//String address = request.getParameter("address");
		//String sname = request.getParameter("sname");
		//String gender = request.getParameter("gender");
		//String birthday = request.getParameter("birthday");
		//SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		////		Students s = new Students();
		//		s.setSid(sid);
		//		s.setBirthday(sdf.parse(birthday));
		//		s.setAddress(address);
		//		s.setSname(sname);
		//		s.setGender(gender);		
		return "modify_succcess";	
		}

modify.jsp

<div id="mainContainer">
<!-- 从session中获取学生集合 -->
<strong>修改学生资料</strong>
<br>
<br>
<form name="modifyForm" action="<%=path%>/students/Students_modify.action" method="post">
<table width="400" > 
 <tr>    
 <td width="30%">学号：</td>   
  <td><input type="text" name="sid" value='<s:property value="#session.modify_students.sid"/>'  readonly="readonly"/></td>  </tr>  <tr>    <td width="30%">姓名：</td>  
  <td><input type="text" name="sname" value='<s:property value="#session.modify_students.sname"/>'/></td> 
   </tr> 
    <tr>  
      <td>性别：</td> 
       <td>   <s:if test='%{#session.modify_students.gender=="男"}'> 
    <input type="radio" name="gender" value="男" checked="checked"/>男    
         <input type="radio" name="gender" value="女"/>女  </s:if> 
    <s:else>  <input type="radio" name="gender" value="男" />男       
      <input type="radio" name="gender" value="女" checked="checked"/>女     
     </s:else>   
       </td> 
        </tr>  
      <tr> 
         <td>出生日期：</td>  
          <td><input name="birthday" type="text" id="control_date" size="20"  maxlength="10" onclick="new Calendar().show(this);" readonly="readonly" value="<s:date name="#session.modify_students.birthday" format="yyyy-MM-dd"/>"      />  
            </td>  </tr>  <tr>    <td>地址：</td>    <td><input type="text" name="address" value='<s:property value="#session.modify_students.address"/>'/></td>  </tr>
             <tr>    
             <td colspan="2" align="center">
             <input class="button" type="submit" value="修改"></td>  
             </tr>
             </table>
             </form>
             </div>