Thymeleaf复选框没有传递值

本文介绍了Thymeleaf复选框没有传递值的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

两个问题。

我有User和Note类。用户可以有很多笔记。如何通过Thymeleaf展示属于用户的每个笔记？ th：text =$ {u.notes.id}不起作用

我有表格（见图片），每个用户的复选框都有布尔值isUserChecked值，下面是按钮删除已检查的用户Thymeleaf正确显示isUserChecked值的状态。当我手动选中复选框时，删除按钮不起作用，但是当我在代码中设置isUserChecked值时，该按钮有效。问题在于我的Thymeleaf语法中的这个复选框。

屏幕截图：

html

<div class="container"> <div class="row"> <div class="col-sm-6"> <table class="table table-hover"> <thead> <tr> <th>Id</th> <th>Username</th> <th>First name</th> <th>Last name</th> <th>Password (Hash)</th> <th>Role</th> <th>Notes</th> <th>Select</th> </tr> </thead> <tbody> <tr th:each="u : ${listOfUsers}"> <td th:text="${u.id}"></td> <td th:text="${u.username}"></td> <td th:text="${u.firstName}"></td> <td th:text="${u.lastName}"></td> <td th:text="${#strings.substring(u.password,0,5) +'...'}"></td> <td th:text="${u.role}"></td> <td th:text="${u.notes}"></td> <td><input type="checkbox" name="mycheckbox" th:value="*{u.isUserChecked()}" th:checked="${u.isUserChecked()}" /></td> </tr> </tbody> </table> <form th:action="@{/users}" method="post"> <button class="buttonLogin" type="submit">Submit</button> </form> </div> </div>

更新1

正如@Metroids提到的第一个问题可以解决：

as @Metroids mentioned first problem can fix by:

< td>< span th：each =note，i： $ {u.notes}th：text =$ {（i.index> 0？'，'：''）+ note.id}/>< / td>

第二个问题。在我的html中使用它：

Second problem. For using this in my html:

<tr th:each="u, i : ${userWrapper}"> <!-- other rows removed for readability --> <td><input type="checkbox" th:field="*{listOfUsers[__${i.index}__].userChecked}" /></td>

我需要带有属性的UserWrapper类列表<使用者> listOUsers 。但是怎么做呢？ 我创建了这样的东西：

i need UserWrapper class with property List<User> listOUsers. But how to do this ? I created something like this:

@Component public class UserWrapper { @Autowired UserService userService; List<User> listOfUsers = userService.findAll(); public List<User> getListOfUsers() { return listOfUsers; } public void setListOfUsers(List<User> listOfUsers) { this.listOfUsers = listOfUsers; } }

以下是此页面的控制器：

Here is my controller for this page:

@Controller public class UserController { @Autowired UserService userService; @Autowired UserWrapper userWrapper; @RequestMapping("/users") public String home(Model model){ List<User> listOfUsers = userService.findAll(); model.addAttribute("listOfUsers", listOfUsers); return "users"; } @RequestMapping(value = "users", method = RequestMethod.POST) public String deleteUser(User user, Model model){ userService.deleteCheckedUser(user); return "redirect:/users"; } }

此后我有错误：

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'userController': Unsatisfied dependency expressed through field 'userWrapper'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userWrapper' defined in file [C:\Users\luk89\Desktop\Java\STS Projects\StickyNotes\target\classes\com\twistezo\models\UserWrapper.class]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.twistezo.models.UserWrapper]: Constructor threw exception; nested exception is java.lang.NullPointerException

更新2

用户控制器：

@Controller public class UserController { @Autowired UserService userService; @Autowired UserWrapper userWrapper; @RequestMapping("/users") public String home(Model model){ List<User> listOfUsers = userService.findAll(); userWrapper.setListOfUsers(listOfUsers); for(User u : userWrapper.getListOfUsers()){ System.out.println("username: " +u.getUsername()+ ", checked?: " +u.isUserChecked()); } model.addAttribute("listOfUsers", listOfUsers); model.addAttribute("userWrapper", userWrapper); return "users"; } @RequestMapping(value = "/users", method = RequestMethod.POST) public String deleteUser(@ModelAttribute UserWrapper userWrapper, Model model){ for(User u : userWrapper.getListOfUsers()){ System.out.println("username: " +u.getUsername()+ ", checked?: " +u.isUserChecked()); } userService.deleteCheckedUser(userWrapper); return "redirect:/users"; } }

从我的服务类中删除方法：

Delete method from my service class:

@Override public void deleteCheckedUser(UserWrapper userWrapper) { for(User u : userWrapper.getListOfUsers()){ if(u.isUserChecked() == true){ this.userDAO.delete(u.getId()); } } }

结果：

username: user1, checked?: false username: user2, checked?: false username: user3, checked?: false username: user4, checked?: false username: user5, checked?: false username: asd, checked?: false username: qwe, checked?: false username: xcv, checked?: false username: ghj, checked?: false username: dfh, checked?: false username: n, checked?: false username: ed, checked?: false username: null, checked?: true username: null, checked?: false username: null, checked?: false username: null, checked?: false username: null, checked?: false username: null, checked?: false username: null, checked?: false username: null, checked?: false username: null, checked?: false username: null, checked?: false username: null, checked?: false username: null, checked?: true

Thymeleaf部分现在很棒，但是当我在控制器中调用POST方法时，我的userWrap列表没有值。我正在尝试复制

Thymeleaf part wokrs great now, but my list from userWrap doesn't have values when i call POST method in controller. I was trying copy

List< User> listOfUsers = userService.findAll（）; userWrapper.setListOfUsers（listOfUsers）;

到POST方法但是有这样的情况：用户名：好的，检查了吗？：没有' t听鼠标点击复选框（所有值都为false）。

to POST method but there was situation: usernames: OK, checked?: doesn't listen mouse clicking to checkbox (all values are false).

推荐答案

列表中需要添加的每个音符的id另一个循环。例如，代替

For the listing the id of every note you need to add another loop. For example, instead of

<td th:text="${u.notes}"></td>

你需要类似的东西。

<td><span th:each="note, i: ${u.notes}" th:text="${(i.index > 0 ? ', ' : '') + note.id}" /></td>

-

复选框。您需要进行大量更改...

For the checkbox. You have a lot of changes you need to make...

• 所有复选框都必须位于< ; form>< / form> tags。
• 您需要一个具有用户列表作为属性的命令对象...我不认为您可以使用java List作为命令对象。需要将其指定为< form> 标记上的th：对象。
• 实际复选框的html应该看起来如此类似这样的事情：

• All the checkboxes need to be within the <form></form> tags.
• You need a command object that has a list of users as a property... I don't think you can use a java List as the command object. That needs to be specified as the th:object on the <form> tag.
• The html for the actual checkbox should look something like this:

HTML

<form th:action="@{/users}" th:object="${userWrapper}" method="post"> <!-- other html removed for readability --> <tr th:each="u, i : ${listOfUsers}"> <!-- other rows removed for readability --> <td><input type="checkbox" th:field="*{users[__${i.index}__].userChecked}" /></td> </tr> </form>

控制器

@Controller public class UserController { @Autowired UserService userService; @RequestMapping("/users") public String home(Model model){ List<User> listOfUsers = userService.findAll(); UserWrapper userWrapper = new UserWrapper(); userWrapper.setListOfUsers(listOfUsers); model.addAttribute("listOfUsers", listOfUsers); model.addAttribute("userWrapper", userWrapper); return "users"; } @RequestMapping(value = "users", method = RequestMethod.POST) public String deleteUser(@ModelAttribute UserWrapper userWrapper, Model model){ userService.deleteCheckedUser(userWrapper.getListOfUsers()); return "redirect:/users"; } }

Java

public class UserWrapper { List<User> listOfUsers = new ArrayList<>(); public List<User> getListOfUsers() { return listOfUsers; } public void setListOfUsers(List<User> listOfUsers) { this.listOfUsers = listOfUsers; } }