java - 无法使用 Jackson XML 直接在根元素内反序列化列表

Question

我无法反序列化作为根元素子目录的列表，我尝试了各种方法。

我的代码:

private static class Cards {
    @JacksonXmlElementWrapper(localName = "Cards")
    private List<Card> cards;

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

private static class Card {
    @JsonProperty("Name")
    private String name;

    @JsonProperty("Image")
    private String image;

    @JsonProperty("CardType")
    private String cardType;

    private final Map<String, Integer> resources = new HashMap<>();

    private boolean duplicateResources = false;
    private final List<String> duplicateResourceNames = new ArrayList<>();

    @JsonAnySetter
    private void addResource(final String name, final Object value) {
        if (resources.containsKey(name)) {
            duplicateResources = true;
            duplicateResourceNames.add(name);
        }
        resources.put(name, Integer.parseInt(value.toString()));
    }

    public String getName() {
        return name;
    }

    public String getImage() {
        return image;
    }

    public String getCardType() {
        return cardType;
    }

    @JsonAnyGetter
    public Map<String, Integer> getResources() {
        if (duplicateResources) {
            throw new UncheckedCardLoadingException("Resources " + duplicateResourceNames + " have duplicate entries");
        }
        return new HashMap<>(resources);
    }
}

和:

ObjectMapper xmlMapper = new XmlMapper();
Cards cards = xmlMapper.readValue(path.toFile(), Cards.class);

尝试反序列化以下 XML 时:

<Cards>
    <Card>
        <Name>test</Name>
        <Image></Image>
        <CardType>test</CardType>
    </Card>
</Cards>

它给出错误:

com.cardshifter.core.cardloader.CardLoadingException: com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "Card" (class com.cardshifter.core.cardloader.XmlCardLoader$Cards), not marked as ignorable (one known property: "Cards"]) at [Source: C:\Users\Frank\Dropbox\NetbeansProjects\Cardshifter\cardshifter-core\target\test-classes\com\cardshifter\core\cardloader\single-card.xml; line: 3, column: 9] (through reference chain: com.cardshifter.core.cardloader.Cards["Card"])

Answer 1

首先，看看这些:

@JacksonXmlElementWrapper(localName = "Cards")
private List<Card> cards;

然后看报错:

com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "Card" (class com.cardshifter.core.cardloader.XmlCardLoader$Cards)

在你的类里面没有任何地方说“卡片”。

其次，在解决这个问题之后，我是这样解决你的整个加载问题的:

private static class Cards {
    @JacksonXmlElementWrapper(localName = "Card")
    @JsonProperty("Card")
    private List<Card> card = new ArrayList<>();

    @JsonSetter
    public void setCard(Card card) {
        this.card.add(card);
    }
}

setCard 方法简单地告诉 Jackson，如果遇到这种情况，它应该将其解释为 Card，然后您提供将其添加到数组的方法。