关于java：Thymeleaf返回一个String数组而不是List <Object>

Thymeleaf returning a String array instead of List<Object>

我正在学习如何使用Spring Boot和Thymeleaf。我有一个问题，我在表单列表中向Thymeleaf页面提供了特定对象的列表。当用户选择值并发布结果时，结果是所选对象的字符串，并且与我要在其中存储值的对象不兼容。

这听起来像是一口嘴，所以下面是代码。

我的问题是：是否有任何方法可以确保Thymeleaf返回对象列表？

输入：一个类将一堆配料传递给表单
此类将"成分"类的"列表"传递给表单(此筛选无关紧要-插入一个列表作为model属性的值，且键为成分的类型)

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@GetMapping
public String showDesignForm(Model model) {
List<Ingredient> ingredients = new ArrayList<>();
ingredientRepo.findAll().forEach(i -> ingredients.add(i));
Type[] types = Ingredient.Type.values();
for (Type type : types) {
model.addAttribute(type.toString().toLowerCase(), filterByType (ingredients, type));
}
model.addAttribute("taco", new Taco());
return"design";
}

Thymeleaf获取该列表并将其显示在复选框中

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<!DOCTYPE html>
<html
xmlns:th="http://www.thymeleaf.org">
<head>
Taco Cloud
<link rel="stylesheet" th:href="@{/styles.css}" />
</head>
<body>
Design your taco!
<img th:src="@{/images/TacoCloud.png}"/>
<form method="POST" th:object="${taco}">

Designate your wrap:

<input name="ingredients" type="checkbox" th:value="${ingredient}" />
<span th:text="${ingredient.name}">INGREDIENT</span><br/>

Pick your protein:

<input name="ingredients" type="checkbox" th:value="${ingredient}" />
<span th:text="${ingredient.name}">INGREDIENT</span><br/>

Choose your cheese:

<input name="ingredients" type="checkbox" th:value="${ingredient}" />
<span th:text="${ingredient.name}">INGREDIENT</span><br/>

Determine your veggies:

<input name="ingredients" type="checkbox" th:value="${ingredient}" />
<span th:text="${ingredient.name}">INGREDIENT</span><br/>

Select your sauce:

<input name="ingredients" type="checkbox" th:value="${ingredient}" />
<span th:text="${ingredient.name}">INGREDIENT</span><br/>

Name your taco creation:
<input type="text" th:field="*{name}"/>
<br/>
<button>Submit your taco</button>

</form>
</body>
</html>

目的地类：期望返回的值是List

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package tacos;

import java.util.Date;
import java.util.List;

import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;

import lombok.Data;

@Data
public class Taco {

private Long id;

private Date createdAt;

@NotNull
@Size(min=5, message="Name must be at least 5 characters long")
private String name;
@Size(min=1, message="You must choose at least 1 ingredient")
private List<Ingredient> ingredients;
}

错误：

Field error in object 'taco' on field 'ingredients': rejected value [Ingredient(id=FLTO, name=Flour Tortilla, type=WRAP),Ingredient(id=CHED, name=Cheddar, type=CHEESE)]; codes [typeMismatch.taco.ingredients,typeMismatch.ingredients,typeMismatch.java.util.List,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [taco.ingredients,ingredients]; arguments []; default message [ingredients]]; default message [Failed to convert property value of type 'java.lang.String[]' to required type 'java.util.List' for property 'ingredients'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.String' to required type 'tacos.Ingredient' for property 'ingredients[0]': no matching editors or conversion strategy found]