Jackson XMLWrapper 未能将此 xml 反序列化为 pojo？

Question

考虑下面给定的xml：

<?xml version="1.0"?>
<Records>
    <Record>
        <Prop name="commerce">sku1</Prop>
        <Prop name="commerce">sku2</Prop>
        <Prop name="commerce">sku3</Prop>
        <Prop name="commerce">sku4</Prop>
    </Record>
    <Record>
        <Prop name="commerce">sku10</Prop>
        <Prop name="commerce">sku20</Prop>
        <Prop name="commerce">sku30</Prop>
        <Prop name="commerce">sku40</Prop>
    </Record>
</Records>

现在考虑一下我创建的这些 Pojos（为简洁起见，删除了 getter 和 setter）。

public class Records {
    private List<Record> records;
}

public class Record {
    private List<Prop> props;
}

public class Prop {
    // I want to capture name attribute
    private String name;
    // But I also want to capture what comes inside Prop element as well. This would then have values like sku1, sku2 etc
    private String text;
}

现在我有了像这样使用 XMLWrapper 的代码。

File file = ResourceUtils.getFile("classpath:sample.xml"); // the above XML is sample.xml
XmlMapper xmlMapper = XmlMapper.builder().build();
Records records = xmlMapper.readValue(file, Records.class); // this line is failing

但是我遇到了这样的错误

Caused by: com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "Record" (class com.example.demo.model.xml.Records), not marked as ignorable (one known property: "records"])

Answer 1

即使没有 XML 注释（大部分情况下），这个解决方案似乎也适合我。为后代张贴。

第 1 步：禁用换行。

File file = ResourceUtils.getFile("classpath:sample.xml"); 
XmlMapper xmlMapper = XmlMapper.builder().defaultUseWrapper(false).build();
Records records = xmlMapper.readValue(file, Records.class);

第 2 步：使用 JsonProperty 注释更新 pojos（唯一的例外是使用 @JacksonXmlText 获取内部值。为简洁起见，请注意删除 setter 和 getter。

public class Records {
    @JsonProperty("Record")
    private List<Record> records;
}

public class Record {
    @JsonProperty("Prop")
    private List<Prop> props;
}

public class Prop {
    @JsonProperty("name")
    private String name;

    @JacksonXmlText
    private String text;
}

以上对我有用。

Answer 2

您必须将@JacksonXmlProperty 注释与指示包装器元素的@JacksonXmlElementWrapper 注释结合使用Collection：在这种情况下，可选属性useWrapping 设置为false 明确禁用包装：

public class Records {
    @JacksonXmlProperty(localName = "Record")
    @JacksonXmlElementWrapper(useWrapping = false)
    private List<Record> records;
}

public class Record {
    @JacksonXmlProperty(localName = "Prop")
    @JacksonXmlElementWrapper(useWrapping = false)
    private List<Prop> props;
}

public class Prop {
    //<Prop name="commerce">sku1</Prop> name is an attribute with value commerce
    @JacksonXmlProperty(localName= "name", isAttribute = true)
    private String name;
    
    //<Prop name="commerce">sku1</Prop> sku1 is the text inside the Prop tags
    @JacksonXmlText
    private String text;
}