老师,我的显示不能强制Message
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>系统登录</title> <link href="form.css" rel="stylesheet" type="text/css"/> </head> <body> <form action="login.jsp" method="post" class="smart-green"> <h1>系统登录</h1> <label> <span>用户名:</span> <input id="username" type="text" name="username"/> </label> <label> <span>密码:</span> <input id="password" type="password" name="password"/> </label> <span> </span> <label> <input type="submit" class="button" value="登录"> </label> </form> </body> </html>
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<%
String username=request.getParameter("username");
String password=request.getParameter("password");
session.setAttribute("loginUser", username);
response.sendRedirect(request.getContextPath()+"/message.jsp");
%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="java.util.*,model.*"%>
<%
String user=(String)session.getAttribute("loginUser");
String subFlag=request.getParameter("subFlag");
List<Message> messages = (List<Message>)session.getAttribute("messages");
%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>留言板</title>
<link href="form.css" rel="stylesheet" type="text/css"/>
<link href="table.css" rel="stylesheet" type="text/css"/>
</head>
<script type="text/javascript">
var subFlag='<%=subFlag%>';
if(subFlag=='1'){
alert("留言成功");
}
</script>
<body>
<form action="messageSub.jsp" method="post" class="smart-green">
<h1>留言板</h1>
<label>
<span>留言人</span>
<input id="user" type="text"value="<%=user%>" readonly="readonly"/>
</label>
<label>
<span>标题</span>
<input id="title" type="text"name="title" value=""/>
</label>
<label>
<span>内容</span>
<textarea id="content" name="centent"></textarea>
</label>
<span> </span>
<label>
<input type="submit" class="button" value="提交"/>
</label>
</form>
<br/>
<table id="table-3" width="85%" align="center">
<tr>
<th width="15%">留言人</th>
<th width="15%">标题</th>
<th width="70%">内容</th>
</tr>
<%
if(messages!=null){
for(Message message:messages){
%>
<tr>
<td><%=user %></td>
<td><%=message.getTitle() %></td>
<td><%=message.getContent() %></td>
</tr>
<%
}
}
%>
</table>
</body>
</html>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="java.util.*,model.*"%>
<%
String title=request.getParameter("title");
String content=request.getParameter("content");
Message message=new Message();
message.setTitle(title);
message.setContent(content);
List<Message> messages=(List<Message>)session.getAttribute("messages");
if(messages==null){
messages=new ArrayList<Message>();
session.setAttribute("messages", message);
}
messages.add(message);
response.sendRedirect(request.getContextPath()+"/message.jsp?subFlag=1");
%>
正在回答
同学你好。
messageSub.jsp中,同学少写了一个s。将message存进去了,message是Message对象,不能强转成List<Message>:

如果还有疑问,可以继续提问。如果解答了同学的疑问,望采纳~
祝学习愉快~
- 参与学习 人
- 提交作业 1088 份
- 解答问题 10204 个
如果你有Java语言基础,又想以后从事Java Web开发,那么本路径是你的不二选择!本路径从网页搭建开始入手,通过大量案例来学习Java Web基础。定能助你完成Java Web小白的蜕变!
了解课程
恭喜解决一个难题,获得1积分~
来为老师/同学的回答评分吧
0 星