Question

我在一个简单的 Spring Boot 应用程序中遇到错误。

我的错误： Bean属性'menu'无法读取或getter方法无效：getter的返回类型是否与setter的参数类型匹配？

当我点击 Thymeleaf 视图中的“添加菜单”按钮时，会出现问题。我在网上搜索了可能的解决方案，即使它看起来像是一个直接的bug，我也不知道如何管理它。

我多次更改并检查了Menu类，但我没有发现问题。

该应用程序用于创建带有奶酪的自定义菜单。

MenuController：

package com.ghiurutan.springdemo.controllers;

import com.ghiurutan.springdemo.data.CheeseDAO;
import com.ghiurutan.springdemo.data.MenuDAO;
import com.ghiurutan.springdemo.models.Cheese;
import com.ghiurutan.springdemo.models.Menu;
import com.ghiurutan.springdemo.models.forms.AddMenuItemForm;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.Errors;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.validation.Valid;

@Controller
@RequestMapping("menu")
public class MenuController {

    @Autowired
    private MenuDAO menuDAO;

    @Autowired
    private CheeseDAO cheeseDAO;

    @RequestMapping(value = "")
    public String index(Model model) {
        model.addAttribute("title", "Menus");
        model.addAttribute("menus", menuDAO.findAll());
        return "menu/index";
    }

    @RequestMapping(value = "add", method = RequestMethod.GET)
    public String add(Model model) {
        model.addAttribute("title", "Add Menu");
        model.addAttribute(new Menu());
        return "menu/add";
    }

    @RequestMapping(value = "add", method = RequestMethod.POST)
    public String add(Model model, @ModelAttribute @Valid Menu menu, Errors errors) {
        if (errors.hasErrors()) {
            model.addAttribute("title", "Add Menu");
            model.addAttribute(new Menu());
            return "menu/add";
        }

        menuDAO.save(menu);
        return "redirect:view/" + menu.getId();
    }

    @RequestMapping(value = "view/{menuId}", method = RequestMethod.GET)
    public String viewMenu(Model model, @PathVariable int menuId) {
        Menu menu = menuDAO.findOne(menuId);
        model.addAttribute("title", menu.getName());
        model.addAttribute("cheeses", menu.getCheeses());
        model.addAttribute("menuId", menu.getId());

        return "menu/view";
    }

    @RequestMapping(value = "add-item/{menuId}", method = RequestMethod.GET)
    public String addItem(Model model, @PathVariable int menuId) {
        Menu menu = menuDAO.findOne(menuId);

        AddMenuItemForm form = new AddMenuItemForm(cheeseDAO.findAll(), menu);

        model.addAttribute("title", "Add item to menu: " + menu.getName());
        model.addAttribute("form", form);
        return "menu/add-item";
    }

    @RequestMapping(value = "add-item", method = RequestMethod.POST)
    public String addItem(Model model, @ModelAttribute @Valid AddMenuItemForm form, Errors errors) {
        if (errors.hasErrors()) {
            model.addAttribute("form", form);
            model.addAttribute("title", "Add item to menu: " + form.getMenu().getName());
            return "menu/add-item";
        }
        Cheese cheese = cheeseDAO.findOne(form.getCheeseId());
        Menu menu = menuDAO.findOne(form.getMenuId());
        menu.addItem(cheese);
        menuDAO.save(menu);

        return "redirect:/menu/view/" + menu.getId();
    }

}

菜单模型类：

package com.ghiurutan.springdemo.models;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;
import java.util.List;

@Entity
public class Menu {

    @Id
    @GeneratedValue
    private int id;

    @NotNull
    @Size(min = 3, max = 15)
    private String name;

    @ManyToMany
    private List<Cheese> cheeses;

    public Menu() {
    }

    public int getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void addItem(Cheese item) {
        cheeses.add(item);
    }

    public List<Cheese> getCheeses() {
        return cheeses;
    }
}

我按下添加菜单按钮的百里叶视图：

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org/">
<head th:replace="fragments :: head"></head>
<body class="container">

<h1 th:text="${title}">Default title</h1>

<nav th:replace="fragments :: navigation"></nav>

<ul>
    <li th:each="menu : ${menus}">
        <a th:href="'/menu/view/' + ${menu.id}" th:text="${menu.name}"></a>
    </li>
</ul>

<p>
    <a href="/menu/add">Add Menu</a>
</p>

</body>
</html>

在尝试渲染时崩溃的百万美元视图模板：

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org/">
<head th:replace="fragments :: head"></head>
<body class="container">
<h1 th:text="${title}">Default Title</h1>

<nav th:replace="fragments :: navigation"></nav>

<form method="post" style="max-width: 600px" th:object="${menu}">
    <div class="form-group">
        <label th:for="name">Name</label>
        <input class="form-control" th:field="*{menu}"/>
        <span th:errors="*{name}" class="error"></span>
    </div>
    <input type="submit" value="Create Menu"/>
</form>

</body>
</html>

在网页中出现：执行处理器'org.thymeleaf.spring4.processor.attr.SpringInputGeneralFieldAttrProcessor'时出错（菜单/添加：12）

第12行是：<input class="form-control" th:field="*{menu}"/>

非常感谢！

Spring引用Bean属性不可读

0 个答案: