Java 为什么可以';t我从模型中检索属性,但我';我能从JSP下载吗?
我正在学习SpringMVC并了解Model和ModelAttribute的使用。但是,我无法检索模型的属性,因此我求助于使用JSP参数值。我做错了什么?我使用Java 为什么可以';t我从模型中检索属性,但我';我能从JSP下载吗?,java,spring,spring-mvc,Java,Spring,Spring Mvc,我正在学习SpringMVC并了解Model和ModelAttribute的使用。但是,我无法检索模型的属性,因此我求助于使用JSP参数值。我做错了什么?我使用@modeldattribute(“username”)User/User.username检查了该模型是否仍然有属性值,果然有 控制器 package login.user; import org.springframework.stereotype.Controller; import org.springframework.
@modeldattribute(“username”)User/User.username检查了该模型是否仍然有属性值,果然有
控制器
package login.user;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class LoginUser {
@RequestMapping("/")
public String showMenu()
{
return "menu";
}
@RequestMapping("login")
public String loginUser(Model model)
{
User newUser = new User();
model.addAttribute("user", newUser);
return "login-user";
}
@RequestMapping("processUser")
public String processUser(Model model)
{
Option newOption = new Option();
model.addAttribute("option", newOption);
return "process-login";
}
}
使用者
login-user.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<!DOCTYPE html>
<html>
<head>
<link href="<c:url value="/resources/css/style.css" />" rel="stylesheet" type="text/css" />
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Login User</title>
</head>
<body>
<div>
<form:form action="processUser" modelAttribute="user">
<table>
<tr>
<td>Username:</td>
<td>
<form:input path="username" />
</td>
</tr>
<tr>
<td>Password:</td>
<td>
<form:input type="password" path="password" />
</td>
</tr>
<tr>
<td>
<input type="submit" name="Login" />
</td>
</tr>
</table>
</form:form>
</div>
</body>
</html>
登录用户
用户名:
密码:
process-login.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<form:form modelAttribute="option">
<h3>Welcome ${param.username}. Please choose an activity below</h3> <---- changed from ${user.username}
<div>
<form:select path="option">
<form:option value="Email" label="Email"></form:option>
<form:option value="Enter Recipe" label="Enter Recipe"></form:option>
<form:option value="Retrieve Recipe" label="Retrieve Recipe"></form:option>
</form:select>
</div>
</form:form>
</body>
</html>
在此处插入标题
欢迎${param.username}。请选择下面的活动spring模型数据存储在标准Java请求范围中。如果您试图获取用户名,则需要再次将其添加到请求范围中。因此,您可以编写processUser
方法,如下所示
@RequestMapping("processUser")
public String processUser(@ModelAttribute("user") User user,Model model)
{
Option newOption = new Option();
// do stuff with user data
newOption.setUsername(user.getUsername());
model.addAttribute("option", newOption);
return "process-login";
}
因此,您应该能够在jsp中以${option.username}
的形式获取它 只需更改上一个@RequestMapping
方法,如下所示:
@RequestMapping("processUser")
public String processUser(@ModelAttribute("user") User user, Model model)
{
Option newOption = new Option();
model.addAttribute("user", user);
model.addAttribute("option", newOption);
return "process-login";
}
现在在jsp中使用${user.username}。感谢您解释请求范围约束
@RequestMapping("processUser")
public String processUser(@ModelAttribute("user") User user, Model model)
{
Option newOption = new Option();
model.addAttribute("user", user);
model.addAttribute("option", newOption);
return "process-login";
}