无法将类型“java.lang.String”的值转换为所需类型“java.time.LocalDate”

Question

为了运行应用程序，我在 war 中使用了 tomcat 8.5.50 包。我使用弹簧 5.2 版本。 在所有操作中我都使用 JpaRepository。我没有在我的代码中使用日期时间转换器 - 也许这是一个错误？ 我想使用 jsp 在我的表中添加一个日期：

<div id="row">
        <%--@elvariable id="mealsCreate" type=""--%>
        <form:form action="${pageContext.request.contextPath}/create"
                   modelAttribute="mealsCreate" method="post">
            <div class="col-md-9">
                <input type="hidden"/>

                <div class="form-group">
                    <div class="col-md-12">
                        <label for="dateTime">DateTime</label>
                        <input id="dateTime" type="date" name="datetime"/>
                    </div>
                </div>

                <div class="form-group">
                    <div class="col-md-12">
                        <label for="description" type="table" class="table">Description</label>
                        <input id="description" type="text" name="description"/>
                    </div>
                </div>

                <div class="form-group">
                    <div class="col-md-12">
                        <label for="calories" type="table" class="table">Calories</label>
                        <input id="calories" type="number" name="calories"/>
                    </div>
                </div>

                <button type="submit" class="btn btn-default" name="saveMeals">Save</button>
                <button type="button" class="btn btn-default" name="cancelMeals" onclick="window.history.back()">Cancel</button>

            </div>
        </form:form>
    </div>

但我得到一个错误：

日志错误：

字段“datetime”上的对象“mealsCreate”中的字段错误：被拒绝 价值[2020-04-29]；代码 [typeMismatch.mealsCreate.datetime,typeMismatch.datetime,typeMismatch.java.time.LocalDate,typeMismatch]; 论据 [org.springframework.context.support.DefaultMessageSourceResolvable： 代码 [mealsCreate.datetime,datetime];论据 [];默认消息 [约会时间]];默认消息[无法转换类型的属性值 'java.lang.String' 到属性所需的类型'java.time.LocalDate' '约会时间';嵌套异常是 java.lang.IllegalStateException： 无法将类型“java.lang.String”的值转换为所需类型 属性“日期时间”的“java.time.LocalDate”：没有匹配的编辑器或 找到转换策略]] 22:16:59.659 [localhost-startStop-2] INFO o.s.o.j.LocalContainerEntityManagerFactoryBean - 关闭 JPA 持久性单元“默认”的 EntityManagerFactory

我的模特：

@Entity
@Table(name="meals")
public class Meal {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "id")
    private int id;

    @Column(name = "date_time")
    private LocalDate datetime;

    @Column(name = "description")
    private String description;

    @Column(name = "calories")
    private int calories;

    public Meal() {
    }

    public Meal(int id) {
        this.id = id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public int getId() {
        return id;
    }

    public LocalDate getDatetime() {
        return datetime;
    }

    public void setDatetime(LocalDate datetime) {
        this.datetime = datetime;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public int getCalories() {
        return calories;
    }

    public void setCalories(int calories) {
        this.calories = calories;
    }
}

也没有将任何内容加载到数据库中。 我的sql查询：

CREATE TABLE meals
(
  id integer NOT NULL,
  date_time date,
  description text NOT NULL,
  calories integer NOT NULL,
  CONSTRAINT meals_pkey PRIMARY KEY (id)
)

控制器：

@Controller
public class Controller {
    @Autowired
    MealService mealService;

    @GetMapping(value = "/list")
    public String getAll(Model model) {
        model.addAttribute("meals", mealService.getAll());

        return "meals";
    }

    @GetMapping(value = "/createForm")
    public String addForm(Model model) {
        Meal meal = new Meal();
        model.addAttribute("mealsCreate", meal);

        return "createmealForm";
    }

    @PostMapping(value = "/create")
    public String save(@ModelAttribute("mealsCreate") Meal meal) {
        mealService.save(meal);
        return "redirect:/list";
    }
}

我的代码有什么问题？

Answer 1

import org.springframework.web.bind.WebDataBinder;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.InitBinder;

import java.beans.PropertyEditorSupport;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;

/**
 * @author yangxin
 * @date 2020/10/27 15:32
 * @since V1.0
 */
@ControllerAdvice
public class ControllerInitBinderHandler {

    @InitBinder
    protected void initBinder(WebDataBinder binder) {
        binder.registerCustomEditor(LocalDate.class, new PropertyEditorSupport() {
            @Override
            public void setAsText(String text) throws IllegalArgumentException {
                setValue(LocalDate.parse(text, DateTimeFormatter.ofPattern("yyyy-MM-dd")));
            }
        });


        binder.registerCustomEditor(LocalDateTime.class, new PropertyEditorSupport() {
            @Override
            public void setAsText(String text) throws IllegalArgumentException {
                setValue(LocalDateTime.parse(text, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
            }
        });


        binder.registerCustomEditor(LocalTime.class, new PropertyEditorSupport() {
            @Override
            public void setAsText(String text) throws IllegalArgumentException {
                setValue(LocalTime.parse(text, DateTimeFormatter.ofPattern("HH:mm:ss")));
            }
        });
    }
}