th：字段未从th：value中抓取数据

Question

好的，所以，基本上我必须使用这个值的输入，以便将它发送到表单post以删除我想要的行...

<input type="text" th:field="*{id}" value="${customer.id}" />

但是会发生什么呢？嗯..属性th:field=“*{id}”未完成其工作，如下所示：

你可以看到的第3个是提交按钮，因为你可以看到它正确地抓取值，但不管我做什么，每次我尝试删除一些东西，它都不行，而且不是，这不是逻辑，因为在一些哑输入上硬编码了html上的id，它起作用了。

以下是html代码：

<form th:action="@{/DeleteCustomer}"
                                th:object="${customersdelete}" method="post">
                                <span th:value="${customer.id}"></span>

                                <span th:field="*{id}" value="${customer.id}"></span>

                                <input type="text" 
                                th:field="*{id}" value="${customer.id}" />

<!--                                <input type="text" th:value="${customer.id}" th:field="*{id}" /> -->

                                <input
                                    type="submit" name="btnInsert" class="btn btn-primary"
                                    value="Delete" th:value="${customer.id}" />
                            </form>

控制器

@PostMapping("/DeleteCustomer")
    public ModelAndView DeletDis(@ModelAttribute("customersdelete") Customers Customers) {
        ModelAndView mav = new ModelAndView();

        System.err.println("ID =" + Customers.getId());
        customersService.removeCustomer(Customers.getId());
        customersService.listAllCustomers();
        mav.setViewName("redirect:/" + MAIN_VIEW);
        return mav;

    }

错误：

ID =0
Hibernate: select customers0_.id as id1_0_0_, customers0_.address as address2_0_0_, customers0_.course as course3_0_0_, customers0_.firstname as firstnam4_0_0_, customers0_.lastname as lastname5_0_0_ from customers customers0_ where customers0_.id=?
2018-02-13 11:17:25.924  INFO 10812 --- [nio-8080-exec-9] c.p.s.component.RequestTimeInterceptor   : --REQUEST URL:'http://localhost:8080/DeleteCustomer'-- TOTAL TIME: '8'ms
2018-02-13 11:17:25.927 ERROR 10812 --- [nio-8080-exec-9] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.dao.EmptyResultDataAccessException: No class com.project.springinventory.entity.Customers entity with id 0 exists!] with root cause

org.springframework.dao.EmptyResultDataAccessException: No class com.project.springinventory.entity.Customers entity with id 0 exists!

                            <input type="text" 
                                th:field="*{id}" value="${customer.id}" />



                            <input type="text" 
                                th:field="*{id}" th:value="${customer.id}" />

                    <input type="hidden" 
                                th:field="*{id}" th:value="${customer.id}" />

检查了对象，检查了一切。我不知道该怎么办。

我看到的是，如果我删除th:field=“*{id}”，id将加载到输入中，但不会发送到post中，尝试创建另一个具有不同名称的对象，以避免数据冲突或其他东西，但仍然相同。

    <tr th:each="customer:${customers}">
                        <th><span th:value="${customer.id}"></span></th>
                        <th><span th:text="${customer.id}"></span></th>
                        <th><span th:text="${customer.firstname}"></span></th>
                        <th><span th:text="${customer.lastname}"></span></th>
                        <th><span th:text="${customer.course}"></span></th>
                        <th><span th:text="${customer.address}"></span></th>
                        <th>
                            <form th:action="@{/showCustomer}" th:object="${customers}"
                                method="post">
                                <button class="btn btn-warning">
                                    <span class="glyphicon glyphicon-pencil" aria-hidden="true">Show</span>
                                </button>
                            </form>
                            <form th:action="@{/UpdateCustomer}" th:object="${customers}"
                                method="post">
                                <button class="btn btn-warning">
                                    <span class="glyphicon glyphicon-pencil" aria-hidden="true">Edit</span>
                                </button>
                            </form>

                            <form th:action="@{/DeleteCustomer}"
                                th:object="${customersdelete}" method="post">
                                <span th:value="${customer.id}"></span>

                                <span th:field="*{id}" value="${customer.id}"></span>

                                <input type="text" 
                                th:field="*{id}" value="${customer.id}" />

<!--                                <input type="text" th:value="${customer.id}" th:field="*{id}" /> -->

                                <input
                                    type="submit" name="btnInsert" class="btn btn-primary"
                                    value="Delete" th:value="${customer.id}" />
                            </form>

Answer 1

th：field设置输入标记的名称、值和id。（覆盖手动设置的某些值。）

由于您的th:object被定义为${customersdelete}，所以表达式*{id}表示${customersdelete.id}--这与您尝试使用th:value=“${customer.id}”时的情况不同。表达式th:value=“${customer.id}”被完全忽略。

您应该在窗体之前设置控制器中customersdelete的id，并且不要使用th:value=“${customer.id}”。