Thyemleaf嵌套迭代触发器org.thymeleaf.exceptions.TemplateInputException

Question

我试图遍历一个对象列表，并为每个4对象生成一个div class=“card-deck”，并为每个对象生成一个嵌套的div class=“card”。

这是生成第234行异常的代码

更新：注意：第234行在HTML中提到并且有<！--错误-第234行-->，因为${#numbers.sequence(0,3}处缺少)

    <div class="card-deck" th:each="qr: ${objects}" th:if="${qr.tableid}%4==0"> <!-- Iterate every 4 objects -->

    <!--syntax error missed clossing ) at ${#numbers.sequence(0,3) triggered the exception here -->
    <div class="card" th:each="i : ${#numbers.sequence(0,3)} ">   <!-- Error-Line 234 -->


        <!-- Some More Code -->
        <img th:src="${qr.qrcodestaticpath}" class="card-img-top" alt="...">
        <div class="card-body">
            <h5 class="card-title" align="center" th:text="'Table '+${qr.tableid}"></h5>
            <p class="card-text" align="center" th:text="'Random Generated QR Code'"></p>
            <h6 align="center" th:text=" ${qr.qrcodestring}"></h6>

        </div>
    </div>
  </div>

templateInputException：模板解析过程中发生错误（模板：“类路径资源[templates/qrcodes.html]”-第234行，第10行）

我已经讨论过这些话题了

• 在Thymeleaf中如何处理if-else？
• Thymeleaf循环直到一个数字
• 带有Thymeleaf的嵌套（双）循环
• Thymeleaf-如何按索引循环列表

并浏览了这些文档

Thymeleaf Baeldung中的
• 迭代

并且仍然无法找到一种正确的方法来完成它，而不触发异常

null

int numOfObjects=11;
    for(int i=0 ;i<numOfObjects;i++)
    {
        if(i%4==0)
        {
           System.out.println();
           System.out.print("Deck:");
        }
          System.out.print("Card"+(i+1)+" ");    
     }

产出：

这是我的控制器

@GetMapping("/qrcodes")
      public String greetingForm(Model model) {

        List<QrObject> qr =qrRepo.findAll();
        int numOfobj= qr.size();
        int decks;

        if(numOfobj % 4==0)
            decks = numOfobj / 4 ;
        else
            decks = (numOfobj / 4) +1 ;

        int posa_periseuoun = numOfobj % 4 ;
        model.addAttribute("objects", qr);
        model.addAttribute("decks",decks);
        model.addAttribute("cards",posa_periseuoun);
        model.addAttribute("size", numOfobj);
        return "qrcodes";
      }

Answer 1

这里有一个方法，我认为它代表了你正在努力做的事情。

跳转到最终结果，这将在浏览器中显示以下文本：

Deck: Card1 Card2 Card3 Card4
Deck: Card5 Card6 Card7 Card8
Deck: Card9 Card10 Card11 

更有用的是，HTML如下所示：

<div class="card-deck">
    <span>Deck: </span>
    <span class="card">Card1 </span>
    <span class="card">Card2 </span>
    <span class="card">Card3 </span>
    <span class="card">Card4 </span>
</div>
<div class="card-deck">
    <span>Deck: </span>
    <span class="card">Card5 </span>
    <span class="card">Card6 </span>
    <span class="card">Card7 </span>
    <span class="card">Card8 </span>
</div>
<div class="card-deck">
    <span>Deck: </span>
    <span class="card">Card9 </span>
    <span class="card">Card10 </span>
    <span class="card">Card11 </span>
 </div>

public class Deck {

    private final String deckName;
    private final List<Card> cards = new ArrayList();

    public Deck(String deckName) {
        this.deckName = deckName;
    }

    public List<Card> getCards() {
        return cards;
    }

    public String getDeckName() {
        return deckName;
    }

}

public class Card {

    private final String cardName;

    public Card(String cardName) {
        this.cardName = cardName;
    }

    public String getCardName() {
        return cardName;
    }

}

Map<String, Object> model = new HashMap();

// this is equivalent to your findAll()...
List<Card> allCards = new ArrayList();
for (int i = 1; i<= 11; i++) {
    allCards.add(new Card("Card" + i));
}

int maxCardsPerDeck = 4;        
List<Deck> decks = new ArrayList();

Deck deck;
List<Card> deckCards = new ArrayList();
int cardCount = 0;
for (Card card : allCards) {
    cardCount++;
    deckCards.add(card);
    if (cardCount % maxCardsPerDeck == 0 ||
            cardCount == allCards.size()) {
        deck = new Deck("Deck");
        deck.getCards().addAll(deckCards);
        decks.add(deck);
        deckCards.clear();
    }
}

model.put("decks", decks);

<div class="card-deck"
     th:each="deck: ${decks}">
    <span th:text="${deck.deckName + ': '}">
    </span>
    <span class="card"
          th:each="card: ${deck.cards}"
          th:text="${card.cardName + ' '}">
    </span>
</div>