Question

我有2个实体User和Article

用户

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

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

    @OneToMany(mappedBy = "userId")
    private List<Article> articles;

第

@Entity
@Table(name = "article")
public class Article {
    @Id
    @GeneratedValue
    private Integer articleId;

    private String name;

    @ManyToOne
    @JoinColumn(name = "user_id")
    private User userId;

我可以注册一个用户然后转到他的页面，然后从那里转到一个页面，其中有一个提交文章的表单。

<form:form method="POST" modelAttribute="article"
        action="${pageContext.request.contextPath}/addArticle">
        <table>
            <tbody>
                <tr>
                    <td>Title:</td>
                    <td><form:input path="name"></form:input></td>
                </tr>
                <tr>
                    <td>Author id:</td>
                    <td><form:input path="userId"></form:input></td> 
                </tr>
<%--                <form:input type="text" path="userId" disabled="true"/> --%>
<%--                    <form:input type="hidden" path="id" id="id"/> --%>
                <tr>
                    <td><input value="Add" type="submit"></td>
                    <td></td>
                </tr>
            </tbody>
        </table>
    </form:form>

问题是，我不知道如何将文章与该用户相关联。现在我的ArticleController看起来像这样

ArticleController

@Controller
public class ArticleController {

    @Autowired
    private ArticleService articleService;

    @Autowired
    private UserService userService;

    @RequestMapping(value = "/addArticle/{id}", method = RequestMethod.GET)
    public String addArticle(@PathVariable Integer id, Model model){
        User user = userService.getUserById(id);
        Article article = new Article();
        model.addAttribute("user", user);
        model.addAttribute("article", article);
        return "addArticle";
    }

    @RequestMapping(value = "/addArticle", method = RequestMethod.POST)
    public ModelAndView addArticle(@ModelAttribute Article article) {

        ModelAndView mav = new ModelAndView();
        articleService.addArticle(article);
        mav.setViewName("redirect:/success");
        return mav;
    }
}

我该怎么做呢

<form:input path="userId" disabled="true"></form:input>

会保存用户ID的值吗？我是否需要传递一个id或者它必须是一个用户对象？

这个方法有什么变化？

public ModelAndView addArticle

我正在使用mysql和spring数据jpa

Answer 1

我会删除path="userId"，因为您只输入了ID并且没有传递实际对象并将其替换为名称

<form:input name="userId"></form:input>

然后，您可以将HttpServletRequest request作为附加参数添加到addArticle类

 public ModelAndView addArticle(HttpServletRequest request, @ModelAttribute Article article) {

这应该允许您从表单访问用户ID并检索用户

User user = userService.getUserById(id);

然后你必须设置用户

Article article = new Article();
article.setUser(user)

多对一。如何将一个对象与另一个对象关联起来？

1 个答案: