问百里叶的麻烦。请求处理失败。EL1007E:在null上找不到属性或字段'name‘
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Stack Overflow用户

提问于 2021-07-06 15:05:45

回答 1查看 41关注 0票数 0

在html(百里叶)下面的"

路径为[]的上下文中的servlet资源模板的Servlet.service()抛出异常[请求处理失败；嵌套异常是org.thymeleaf.exceptions.TemplateInputException:模板解析过程中发生的错误(模板："class path dispatcherServlet /ad-edit.html“)]

控制器：

 @GetMapping("/ads/{id}/edit")
public String adEdit(@PathVariable(value = "id") int id, Model model) {
    List<Platform> platforms = platformRepository.findAll();
    List<PlatformDTO> platformDTOList = platforms.stream().map(platform ->
            PlatformDTO.toDTO(platform)).collect(Collectors.toList());
    Ad ad = adRepository.findById(id).orElseThrow(() ->
            new ResponseStatusException(HttpStatus.NOT_FOUND,
                    "Ad having id " + id + " not found"));
    AdDTO adDto = new AdDTO(ad);
    model.addAttribute("platforms", platformDTOList);
    model.addAttribute("adDto", adDto);
    return "ad-edit";
}

@PostMapping("/ads/{id}/edit")
public String adUpdate(@PathVariable(value = "id") int id,
                       @ModelAttribute("adDto") AdDTO adDto,
                       Model model) {
    Ad ad = adRepository.findById(id).orElseThrow(() ->
            new ResponseStatusException(HttpStatus.NOT_FOUND,
                    "Ad having id " + id + " not found"));
    ad.setPlatforms((platformRepository.findAllById(adDto.platformsIds)));
    ad.setName(adDto.name);
    ad.setAssetUrl(adDto.assetUrl);
    adRepository.save(ad);
    return "redirect:/ads";
}

实体和DTO：

@Table(name = "ads")
@EqualsAndHashCode(of = {"name"})
public class Ad {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    private String name;
    private Status status;
    private String assetUrl;
    @ManyToOne(optional = false, cascade = CascadeType.ALL)
    @JoinColumn(name = "campaign_id")
    private Campaign campaign;
    @ManyToMany
    @JoinTable(name = "ads_platforms", joinColumns = @JoinColumn(name = "ad_id"),
            inverseJoinColumns = @JoinColumn(name = "platform_id", nullable = true))
    @Column(name = "platform")
    private List<Platform> platforms;

    public AdDTO(Ad ad) {
        this.id = ad.getId();
        this.name = ad.getName();
        this.assetUrl = ad.getAssetUrl();
        this.status = ad.getStatus();
        this.campaign = ad.getCampaign();
        this.platformsIds = adPlatformIds(ad.getPlatforms());
    }
    List<Integer> adPlatformIds(List<Platform> platforms){
        List<Integer> platformIdsList = platforms.stream().map(platform -> platform.getId()).collect(Collectors.toList());
        return platformIdsList;
    }
}

    @Entity
@Table(name = "platforms")
@EqualsAndHashCode(of = {"name"})
@ToString(of = {"name"})
public class Platform {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", nullable = true)
    private Integer id;
    private String name;
    @ManyToMany
    @JoinTable(name = "ads_platforms", joinColumns = @JoinColumn(name = "platform_id", nullable = true),
            inverseJoinColumns = @JoinColumn(name = "ad_id"))
    @Column(name = "ad")
    private List<Ad> ads;

    public class PlatformDTO {
    public PlatformDTO() {
    }
    public Integer id;
    public String name;
    public List<Integer> adsIds;


    public static PlatformDTO toDTO(Platform platform) {
        if (platform == null)
            return null;
        PlatformDTO platformDTO = new PlatformDTO();
        platformDTO.id = platform.getId();
        platformDTO.name = platform.getName();
        platformDTO.adsIds = platformAdsIds(platform.getAds());
        return platformDTO;
    }
   static List<Integer> platformAdsIds(List<Ad> ads){
        List<Integer> adIdsList = ads.stream().map(ad -> ad.getId()).collect(Collectors.toList());
        return adIdsList;
    }

ad-edit.html：

<!DOCTYPE html>
<html>
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.1/dist/css/bootstrap.min.css" rel="stylesheet"
      integrity="sha384-+0n0xVW2eSR5OomGNYDnhzAbDsOXxcvSN1TPprVMTNDbiYZCxYbOOl7+AMvyTG2x" crossorigin="anonymous">
<link rel="stylesheet" href="/css/style.css"/>
<head>
    <meta charset="UTF-8">
    <title>Редактирование обьявления</title>
</head>
<body>
<header>
    <nav class="navbar navbar-light bg-light">
        <form class="container justify-content-start">
            <h3 class="caption">Редактирование обьявления <span th:text="${ad.name}"></span></h3>
            <button class="navbar-toggler" type="button">
                <a href="../home.html" th:href="@{/home}">На главную</a></button>
            <button type="button" class="btn btn-light">
                <a href="../info.html" th:href="@{/info}">Обе SQL Таблицы</a></button>
            <button type="button" class="btn btn-light">
                <a href="../ads.html" th:href="@{/ads}">Обьявления</a></button>
            <button type="button" class="btn btn-light">
                <a class="link" href="../campaigns.html" th:href="@{/campaigns}">Кампании</a></button>
        </form>
    </nav>
</header>
<form th:object="${adDto}" th:action="@{/ads/{id}/edit}" method="post">
    <input type="text" th:value="${adDto.name}" th:field="*{adDto.name}"
           placeholder="Введите название обьявления" class="form-control">
    <input type="text" th:value="${adDto.assetUrl}" th:field="*{adDto.assetUrl}"
           placeholder="Введите ссылку на рекламу" class="form-control">
        <select class="form-control"  th:field="*{adDto.platformsIds}" multiple="multiple" >
            <div><option th:each="platform : ${platforms}"
                    th:value="${*platform.id*}"
                    th:selected="${adDto.platformsIds.contains(*platform.id*)}"
                    th:text="${*platform.name*}">
            </option></div>
        </select>
    </div>
    <button type="submit" class="btn btn-success">Редактировать</button>
</form>
</body>
</html>