Java 如何使用 Spring 和 Thymeleaf 在下拉列表中显示所有可能的枚举值？
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How to display all possible enum values in a dropdown list using Spring and Thymeleaf?
提问by stevecross
I have a domain object that has an enum property and I want to display a dropdown list with all possible enum values in the form for this object. Imagine the following object:
我有一个具有 enum 属性的域对象，我想在该对象的表单中显示一个包含所有可能枚举值的下拉列表。想象以下对象：
public class Ticket {
private Long id;
private String title;
private State state;
// Getters & setters
public static enum State {
OPEN, IN_WORK, FINISHED
}
}
In my controller I have a method that renders a form for this object:
在我的控制器中，我有一个方法可以为这个对象呈现一个表单：
@RequestMapping("/tickets/new")
public String showNewTicketForm(@ModelAttribute Ticket ticket) {
return "tickets/new";
}
The template looks like this:
模板如下所示：
<form th:action="@{/tickets}" method="post" th:object="${ticket}">
<input type="text" th:field="*{title}" />
<select></select>
</form>
Later it should be transformed to something like this:
后来它应该变成这样：
<form action="/tickets" method="post">
<input type="text" name="title" />
<select name="state">
<option>OPEN</option>
<option>IN_WORK</option>
<option>FINISHED</option>
</select>
</form>
How can I create the select tag? The selected value should also be mapped to the ticket automatically so that I can do something like this in the controller:
如何创建选择标签？选定的值也应该自动映射到票证，以便我可以在控制器中执行以下操作：
@RequestMapping(value = "/tickets", method = RequestMethod.POST)
public String createTicket(@Valid Ticket ticket) {
service.createTicket(ticket);
return "redirect:/tickets";
}
采纳答案by jchampemont
You could do:
你可以这样做：
<select>
<option th:each="state : ${T(com.mypackage.Ticket.State).values()}"
th:value="${state}"
th:text="${state}">
</option>
</select>
回答by fkurth
In addition, if you want to separate the enum ordinal name from the string displayed in the GUI, add additional properties, for example a displayName:
此外，如果要将枚举序号名称与 GUI 中显示的字符串分开，请添加其他属性，例如displayName：
public static enum State {
OPEN("open"),
IN_WORK("in work"),
FINISHED("finished");
private final String displayName;
State(String displayName) {
this.displayName = displayName;
}
public String getDisplayName() {
return displayName;
}
}
And in the html file:
在 html 文件中：
<select>
<option th:each="state : ${T(com.mypackage.Ticket.State).values()}" th:value="${state}" th:text="${state.displayName}"></option>
</select>
This will present the displayNameto the user and allows you to silently change this strings later without refactoring the code. You may add more properties like th:titlethis way.
这将向用户显示displayName并允许您稍后静默更改此字符串而无需重构代码。您可以通过这种方式添加更多属性，例如th:title。
回答by Diego Santa Cruz Mendezú
this worked for me:
这对我有用：
Java:
爪哇：
public enum RoleEnum {
SUPER_ADMIN("SUPER_ADMIN"),
RESTAURANTE_ADMIN("RESTAURANTE_ADMIN");
private final String roleCode;
private RoleEnum(String roleCode) {
this.roleCode = roleCode;
}
}
Thymeleaf:
百里香：
<select class="form-control" id="val-skill" name="role_id">
<option th:each="role : ${T(com.users.enumeration.RoleEnum).values()}" th:value="${role}" th:text="${role}"></option>
</select>
