急！不知道问题出在哪里

Question

我想实现点击相应图片进入一个详情页然后显示相关信息，但是控制台输出了这个错误

前端页面图片也加载不出来了(下面是图1)

详情页的图片也是(下面是图2)

前端的详情页代码是这样的，在homepage里我用temnplate模板输出图1，原本是能显示封面图的。然后点击相应的图片执行Controller跳转页面并把对象传给前端。

<script type="text/html" id="tpl">
            <a href="/illustration/{{illustrationId}}">
                <div class="illustration">
                    <figure class="figure">
                        <img src="{{cover}}" class="figure-img img-fluid rounded" alt="...">
                    </figure>

                    <figcaption class="figure-caption">
                        作者：{{author}}
                        <p class="card-text"><small class="text-muted">上传时间：{{createTime}}</small></p>
                        <span class="heart-icon" style="position: absolute; bottom: 0px; right: 20px;">
                                <i class="bi-heart-fill" style="font-size: 15px; color: #F06292"></i>
                                <span style="font-size: 15px;">{{evaluationQuantity}}</span>
                            </span>
                    </figcaption>
                </div>
            </a>
        </script>

这是跳转的详情页，在这里用el表达式输出内容

<div class="card" style="position: relative;">
              <div class="card-body">
                <h5 class="card-title">${illustration.illustrationName}</h5>
                <p class="card-text">作者：${illustration.author}</p>
                <p class="card-text"><small class="text-muted">上传时间：${illustration.createTime?string('yyyy-MM-dd-HH-mm-ss')}</small></p>
              </div>
              <span class="heart-icon" style="position: absolute; top: 20px; right: 20px;">
                  <i class="bi-heart-fill" style="font-size: 25px; color: #F06292"></i>
                  <span style="font-size: 25px;">${illustration.evaluationQuantity}</span>
              </span>
              <img src="${illustration.cover}" class="card-img-bottom" alt="...">
            </div>

相关的实体类对应数据库表

这是实体类

package org.person.qingtuku.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import com.fasterxml.jackson.annotation.JsonFormat;
import org.springframework.format.annotation.DateTimeFormat;

import java.util.Date;

@TableName("illustration")
public class Illustration {
    @TableId(type = IdType.AUTO)
    @TableField("illustration_id")
    private Long illustrationId;

    @TableField("illustration_name")
    private String illustrationName;

    @TableField("author")
    private String author;

    @TableField("cover")
    private String cover;

    @TableField("evaluation_quantity")
    private Integer evaluationQuantity;

    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss",timezone = "GMT+8")
    @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    @TableField("create_time")
    private Date createTime;

    @TableField("description")
    private String description;

    public String getDescription() {
        return description;
    }

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

    public Long getIllustrationId() {
        return illustrationId;
    }

    public void setIllustrationId(Long illustrationId) {
        this.illustrationId = illustrationId;
    }

    public String getIllustrationName() {
        return illustrationName;
    }

    public void setIllustrationName(String illustrationName) {
        this.illustrationName = illustrationName;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public String getCover() {
        return cover;
    }

    public void setCover(String cover) {
        this.cover = cover;
    }

    public Integer getEvaluationQuantity() {
        return evaluationQuantity;
    }

    public void setEvaluationQuantity(Integer evaluationQuantity) {
        this.evaluationQuantity = evaluationQuantity;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }
}

这是Controller

@GetMapping("/illustration/{id}")
    public ModelAndView showIllustration(@PathVariable("id") Long id) {
        Illustration illustration = illustrationService.selectIllustration(id);
        List<Evaluation> evaluationList = evaluationService.selectByIllustrationId(id);
        ModelAndView mav = new ModelAndView("/illustration");
        mav.addObject("illustration", illustration);
        mav.addObject("evaluationList", evaluationList);
        return mav;
    }

下面是用到的两个service

@Override
    @Transactional(propagation = Propagation.NOT_SUPPORTED,readOnly = true)
    public Illustration selectIllustration(Long illustrationId) {
        Illustration illustration = illustrationMapper.selectById(illustrationId);
        return illustration;
    }

@Override
    public List<Evaluation> selectByIllustrationId(Long illustrationId) {
        Illustration illustration = illustrationMapper.selectById(illustrationId);
        QueryWrapper<Evaluation> queryWrapper = new QueryWrapper<Evaluation>();
        queryWrapper.eq("illustration_id", illustrationId);
        queryWrapper.orderByDesc("create_time");
        List<Evaluation> evaluationList = evaluationMapper.selectList(queryWrapper);
        for (Evaluation eva : evaluationList) {
            User user = userMapper.selectById(eva.getUserId());
            eva.setUser(user);
            eva.setIllustration(illustration);
        }
        return evaluationList;
    }

不知道问题出在哪里

Answer 1

错误提示空。illustration这个对象可能是null
Controller接口方法中，debug跟一下这个对象值。