Spring Thyme Leaf 检查全局错误导致 NPE [英] Spring Thyme Leaf checking for global errors results in NPE

问题描述

为了显示使用 Thyme Leaf 的 Spring MVC 创建的全局错误，我尝试了 http://www.thymeleaf.org/doc/tutorials/2.1/thymeleafspring.html#global-errors:

也就是说:

和

和

当我将它们添加到我的 HTML 时，页面甚至不会呈现，更不用说提交表单了.所有示例都导致:

org.springframework.web.util.NestedServletException:请求处理失败；嵌套异常是 org.thymeleaf.exceptions.TemplateProcessingException:评估 SpringEL 表达式的异常:#fields.hasErrors('global')"

我用 v2.1.4 和 v.2.1.3 试过这个，得到了同样的错误.错误还是我做错了什么?

是的，所有标签都已关闭且格式正确.是的，此代码在表单中.是的，表单的所有其他方面都可以在没有全局错误检查的情况下工作.

以下是损坏的 HTML 的简短版本:

<p th:if="${#fields.hasErrors('global')}" th:errors="*{global}">日期不正确</p><input type="text" th:field="${command.stockNumber}"/><select th:field="*{command.startYear}"><option value="" th:each="year : ${modelYears}" th:value="${year}"th:text="${year}"></option></选择></表单>

还有控制器..

@RequestMapping(value = "/auto/search", method = RequestMethod.POST)公共字符串搜索(@Validated@ModelAttribute("命令")自动搜索命令 autoSearchCommandBindingResult 结果，模型模型) {返回搜索"；}

解决方案

已解决:

在全局错误检查之前的标记中需要

th:object.不幸的是，Spring Thyme Leaf 教程<中没有提到这一点/a>.据推测，我在控制器中覆盖了某个默认表单名称.

在这个工作 html 结果中添加标签:

<div th:object="${command}" th:remove="tag"><p th:if="${#fields.hasErrors('global')}" th:errors="*{global}">日期不正确</p>

<input type="text" th:field="${command.stockNumber}"/><select th:field="*{command.startYear}"><option value="" th:each="year : ${modelYears}" th:value="${year}"th:text="${year}"></option></选择></表单>

.. 其中command"是控制器中表单 bean 的名称.

这个帖子帮我弄明白了.

To display global errors created with Spring MVC with Thyme Leaf, I tried the example given at http://www.thymeleaf.org/doc/tutorials/2.1/thymeleafspring.html#global-errors:

That, is:

<div th:if="${#fields.hasGlobalErrors()}">

and

<ul th:if="${#fields.hasErrors('global')}">

and

<div th:if="${#fields.hasGlobalErrors()}">

When I add them to my HTML, the page won't even render, nevermind about submitting the form. All the examples result in:

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.thymeleaf.exceptions.TemplateProcessingException: Exception evaluating SpringEL expression: "#fields.hasErrors('global')"

I tried this with v2.1.4 and v.2.1.3 and got the same error. Bug or am I doing something wrong?

Yes, the tags are all closed and properly formed. Yes, this code was within a form. Yes, all the other aspects of the form work without the global error check.

Here is a short version of broken HTML:

<form action="search.html" th:action="@{/auto/search}">
<p th:if="${#fields.hasErrors('global')}" th:errors="*{global}">
    Incorrect date
</p>
<input type="text" th:field="${command.stockNumber}" />
<select th:field="*{command.startYear}">
    <option value="" th:each="year : ${modelYears}" th:value="${year}"
            th:text="${year}"></option>
</select>
</form>

And the controller..

@RequestMapping(value = "/auto/search", method = RequestMethod.POST)
public String search(@Validated
                     @ModelAttribute("command")
                     AutoSearchCommand autoSearchCommand
                     BindingResult result, Model model) {
    return "search";
}

解决方案

Solved:

th:object is needed in a tag preceding to the global error check. Unfortunately, this isn't mentioned in the Spring Thyme Leaf tutorial. Presumably, there's a default form name somewhere which I've overridden in my controller.

Adding the tag in results in this working html:

<form action="search.html" th:action="@{/auto/search}">
<div th:object="${command}" th:remove="tag">
    <p th:if="${#fields.hasErrors('global')}" th:errors="*{global}">
        Incorrect date
    </p>
</div>
<input type="text" th:field="${command.stockNumber}" />
<select th:field="*{command.startYear}">
    <option value="" th:each="year : ${modelYears}" th:value="${year}"
            th:text="${year}"></option>
</select>
</form>

.. Where "command" is the name of the form bean in the controller.

This thread helped me figure it out.

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