java - Spring MVC View - 解析占位符

Question

我是 spring mvc 的初学者。这是我的 Controller

@Controller
public class UserController {   
@RequestMapping(value="/register", method = RequestMethod.GET)
public ModelAndView registerUser(){
    User user = new User();
    user.setNickName("aaa");
    user.setId(1);
    user.setEmail("aaa@gmail.com");
    ModelAndView model = new ModelAndView("register", "model", user);
    return model;
}

还有我的用户类

package org.proffart.bet.domain;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="users")
public class User {
    @Id
    @Column(name="id")
    @GeneratedValue
    private Integer id;

    @Column(name="nic_name")
    private String nickName;

    @Column(name="email")
    private String email;

    @Column(name="password")
    private String password;

    @Column(name="balance")
    private Double balance;

    public String getEmail(){
        return email;
    }

    public void setEmail(String email){
        this.email = email;
    }

    public String getNickName(){
        return nickName;
    }

    public void setNickName(String nickName){
        this.nickName = nickName;
    }

    public String getPassword(){
        return password;
    }

    public void setPassword(String password){
        this.password = password;
    }

    public Double getBalance(){
        return balance;
    }

    public void setBalance(Double balance){
        this.balance = balance;
    }

    public Integer getId(){
        return id;
    }

    public void setId(int id){
        this.id = id;
    }
}

我尝试在 jsp View (register.jsp) 中显示某些内容，但不能。请向我解释为什么 Hello ${model.email} 在 jsp 中不起作用。它向我显示文本“Hello ${model.email}”？

Answer 1

这里可能会出现一些问题，通常的怀疑是 web.xml 中定义的容器合规性，旧的 JSP 1.2 必须有该指令，并且您必须将其设置为

<%@ page isELIgnored="false" %>

如果您使用的是默认启用 EL 的较新 JSP 版本，则应确保您的部署描述符 (web.xml) 至少兼容 2.4 版本

<web-app id="WebApp_ID" version="2.4" 
    xmlns="http://java.sun.com/xml/ns/j2ee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
//...
</web-app>

您可以找到更多详情here和 here