将 HTML 输入日期映射到 Java 对象的 LocalDate

Question

我有一个输入字段（类型：'date'）- 谁可以使用 Thymeleaf 将它映射到我的对象中的 'LocalDate' 字段？

对象

public class Project {

    @Id
    private int id;

    private LocalDate startDate;

    private LocalDate endDate;
}

HTML 输入

  <form action="#"
      th:action="@{|/admin/projects/add/save|}"
      th:object="${newProjects}"
      method="POST"
      class="form-horizontal">
        
    <input type="date" class="form-control" id="startDate"
                       placeholder="Project start"
                       th:field="*{startDate}"/>

    <input type="date" class="form-control" id="endDate"
                       placeholder="Project start"
                       th:field="*{endDate}"/>
                       
</form>

如何将输入字段正确映射到 LocalDate startDate 或 endDate？

控制器

//GetMapping for Projects is also there, but I didn't paste it to keep clarity

@PostMapping("/add/save")
public String saveProject(@Valid @ModelAttribute("project") Project project,
                          BindingResult bindingResult,
                          Model model,
                          RedirectAttributes redirectAttributes) {

// bindingResult has error, because Thymeleaf can't map from the input-field to startDate

  if (!bindingResult.hasErrors()) {
      project.save(project);
      return "redirect:/admin/projects/list";
  } else {
      return "admin/projects/add";
  }
}

异常

Failed to convert property value of type 'java.lang.String' to required type 'java.time.LocalDate' for property 'startDate'; nested exception is org.springframework.core.convert.ConversionFailedException: Failed to convert from type [java.lang.String] to type [@javax.persistence.Column java.time.LocalDate] for value '2017-09-08'; nested exception is java.lang.IllegalArgumentException: Parse attempt failed for value [2017-09-08]

Answer 1

您只能绑定可以用简单类型定义的模型对象。当对象从客户端序列化到服务器时，它不知道复杂类型（like java.time.LocalDate），除非它们是用简单类型表示的。对于您的 scnerio，最好的方法是将客户端 HTML 与服务器端 java 对象日期映射为字符串。然后，您可以在服务器端控制器 class 或任何 java 服务 class.

中将字符串对象转换为 java.time.LocalDate

Answer 2

您有几个选择：

1 - 尝试：

@DateTimeFormat(pattern = "yyyy-MM-dd")
private LocalDate startDate;

@DateTimeFormat(pattern = "yyyy-MM-dd")
private LocalDate endDate;

2 - Use Thymeleaf Extras

Answer 3

向 LocalDate 变量添加 @DateTimeFormat(pattern = "yyyy-MM-dd") 注释解决了问题。

将 HTML 输入日期映射到 Java 对象的 LocalDate

Map HTML input date to LocalDate of Java Object

java

thymeleaf

spring-boot

localdate