foreach 生成的 Spring Controller + Thymeleaf 表单（无法访问变量）

Question

在 thymeleaf 中，我生成带有报价的“订单簿”。 它是用另一个 controller 生成的，但我工作正常。 所有数据都被正确打印。 问题是当我想下订单时。 在@Controller 中，我无法从表单中看到变量。 这是 thymeleaf 的一部分代码

<tr th:each="cruise : ${cruises}">
    <form method="post" th:action="@{/makeOrder}" th:object="${cruise}" name="formOrder" modelAttribute="cruise">
        <td><span th:text="${cruise.nameOfCruise}" th:field="${cruise.nameOfCruise}"> nameOfCruise </span></td>
        <td><span th:text="${cruise.id}" th:field="${cruise.id}"> id </span></td>
        <td><span th:text="${cruise.date}"> date </span></td>
        <td><span th:text="${cruise.cost}"> cost </span></td>
        <td><span th:text="${cruise.route.startPlace}"> start </span></td>
        <td><span th:text="${cruise.route.finishPlace}"> finish </span></td>
        <td style="text-align: center;">
            <span> Interested? </span>
                <input type="submit" value="order">
        </td>
    </form>
</tr>

我尝试 PostMapping 方法

@PostMapping(value = "/makeOrder")
public String order(@ModelAttribute Cruise cruise, Model model){
        logger.info(cruise.getNameOfCruise); //NULL
        if(cruise == null) //NOT NULL. It doesn't execute
            logger.info("Cruise is null); 
        ...
}

我试过这种方式，但没有其他效果

public String order(@ModelAttribute("cruise") Cruise cruise, Model model) 

实体 class

package com.zak.cruise.entity;

import lombok.Getter;
import lombok.Setter;

import javax.persistence.*;
import java.sql.Time;
import java.time.LocalDate;

@Entity
@Table(name = "cruise")
@Getter
@Setter
public class Cruise {
    @Id
    @Column(name = "idcruise")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column(name = "name_of_cruise")
    private String nameOfCruise;

    @Column(name = "date")
    private LocalDate date;

    @Column(name = "time")
    private Time time;

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

    @Column(name = "number_of_seats")
    private int numberOfSeats;

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

    @ManyToOne
    @JoinColumn(name = "route_id_route")
    private Route route;

    @ManyToOne
    @JoinColumn(name = "ship_id_ship")
    private Ship ship;

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

    public Cruise() {
    }

    public Cruise(String nameOfCruise, LocalDate date, Time time, int cost, int numberOfSeats, int duration, Route route, Ship ship, String description) {
        this.nameOfCruise = nameOfCruise;
        this.date = date;
        this.time = time;
        this.cost = cost;
        this.numberOfSeats = numberOfSeats;
        this.duration = duration;
        this.route = route;
        this.ship = ship;
        this.description = description;
    }
}

重要的巡航不是 NULL，而是实体 class。 我想知道的一切是如何从表单中提取变量以使用它们。 我指望你的帮助，提前谢谢你

Answer 1

Thymeleaf 仅进行渲染，它不会神奇地添加更多数据以形成基本 html 的帖子。 因此，不发布跨度元素，仅将输入元素发布到 controller。

因此，您要么必须将所有跨度元素更改为输入，要么可以添加带有 id 值的隐藏输入，并从 controller 的数据库中获取相应的 Cruise object