两个问题。
- 我有用户和注释课程。用户可以有很多笔记。如何通过 Thymeleaf 显示属于用户的每个笔记 id？ th:text="${u.notes.id}" 不起作用
- 我有一个表格（见图），其中每个用户都有布尔 isUserChecked 值的复选框，下面是删除选中用户的按钮。 Thymeleaf 正确显示 isUserChecked 值的状态。当我手动检查复选框时，删除按钮不起作用，但当我在代码中设置 isUserChecked 值时，删除按钮起作用。所以问题出在我的 Thymeleaf 复选框语法中。
截屏：
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>
UPDATE 1
正如 @Metroids 提到的第一个问题可以通过以下方式解决：
<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：
<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List<User> listOUsers。但如何做到这一点呢？
我创建了这样的东西：
@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;
}
}
这是我的该页面的控制器：
@Controller
public class UserController {
@Autowired
UserService userService;
@Autowired
UserWrapper userWrapper;
@RequestMapping("/users")
public String home(Model model){
List<User> listOfUsers = userService.findAll();
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";
}
}
之后我有错误：
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
UPDATE 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：
@Override
public void deleteCheckedUser(UserWrapper userWrapper) {
for(User u : userWrapper.getListOfUsers()){
if(u.isUserChecked() == true){
this.userDAO.delete(u.getId());
}
}
}
Result:
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 部分现在工作得很好，但是当我在控制器中调用 POST 方法时，我的用户 Wrap 列表没有值。我正在尝试复制
List<User> listOfUsers = userService.findAll();
userWrapper.setListOfUsers(listOfUsers);
到 POST 方法，但存在情况：用户名：确定，已检查？：不监听鼠标单击复选框（所有值均为 false）。
