我正在开发一个 Spring Boot 应用程序。我有以下 Thymeleaf 块：
    <Produkt th:if="${visibility}" th:each="user: ${userList.myList}">
        <Name th:text="${user.name}"/>
    </Produkt>
我有以下 Java 代码：
    @Test
    public void myTest() {
        Context context = new Context();
        Map<String, List<Map<String, String>>> userValuesList = new HashMap<>();
        boolean visibility = getVisibility();
        if (visibility) {
            List<Map<String, String>> vv = new ArrayList<>();
            Map<String, String> map = new HashMap<>();
            map.put("name", "filip");
            vv.add(map);
            Map<String, String> map2 = new HashMap<>();
            map2.put("name", "test");
            vv.add(map2);
            userValuesList.put("myList", vv);
        }
        context.setVariable("visibility", visibility);
        context.setVariable("userList", userValuesList);
        springTemplateEngine.process("test.xml", context);
    }
因为我只在 visibility 为 true 时添加这个 myList，我得到了以下错误：
**在评估 SpringEL 表达式时出现异常："userList.myList"**
我的问题是，是否可能仅在 visibility 为 true 时由 springTemplateEngine 处理这个 userList.myList？
我想要实现的最终结果是：
    <Produkt>
        <Name>filip</Name>
    </Produkt>
    <Produkt>
        <Name>test</Name>
    </Produkt>
如果 visibility 为 false，在这种情况下，整个 Produkt 标签都会消失。

Thymeleaf的`th:each`属性的优先级高于`th:if`属性。所有Thymeleaf属性都定义了一个数值优先级，该优先级确定了它们在标签中执行的顺序。要实现您的要求，只需在其自己的标签中使用`th:if`属性，该标签将作为包含`th:each`属性的标记的容器...
    <div th:if="${visibility}">
        <Produkt th:each="user: ${userList.myList}">
            <Name th:text="${user.name}"/>
        </Produkt>
    </div>

<details>
<summary>英文:</summary>
Thymeleaf `th:each` attribute has higher [precedence][1] than `th:if` attribute. All Thymeleaf attributes define a numeric precedence, which establishes the order in which they are executed in the tag. To achieve your requirements just use `th:if` attribute in it&#39;s own tag which will be a container to the tag with `th:each` attribute ...
    &lt;div th:if=&quot;${visibility}&quot;&gt;
        &lt;Produkt th:each=&quot;user: ${userList.myList}&quot;&gt;
            &lt;Name th:text=&quot;${user.name}&quot;/&gt;
        &lt;/Produkt&gt;
    &lt;/div&gt;
  [1]: https://www.thymeleaf.org/doc/tutorials/3.0/usingthymeleaf.html#attribute-precedence
</details>