JAXB 解组问题

Question

我必须在 Java 对象中解析以下 xml：

<ArrayOfTranslateArrayResponse xmlns="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2" xmlns:i="http://www.w3.org/2001/XMLSchema-instance">
<TranslateArrayResponse>
    <From>it</From>
    <OriginalTextSentenceLengths xmlns:a="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
        <a:int>5</a:int>
    </OriginalTextSentenceLengths>
    <TranslatedText>Mom</TranslatedText>
    <TranslatedTextSentenceLengths xmlns:a="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
        <a:int>3</a:int>
    </TranslatedTextSentenceLengths>
</TranslateArrayResponse>
<TranslateArrayResponse>
    <From>it</From>
    <OriginalTextSentenceLengths xmlns:a="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
        <a:int>4</a:int>
    </OriginalTextSentenceLengths>
    <TranslatedText>Dad</TranslatedText>
    <TranslatedTextSentenceLengths xmlns:a="http://schemas.microsoft.com/2003/10/Serialization/Arrays">
        <a:int>3</a:int>
    </TranslatedTextSentenceLengths>
</TranslateArrayResponse>

这是我实现的两个类：

@XmlRootElement(name="ArrayOfTranslateArrayResponse")
@XmlAccessorType(XmlAccessType.FIELD)
@Getter
@Setter
@ToString
public class TranslateResponse {

    @XmlElement(name="TranslateArrayResponse")
    private LinkedList<TranslatedResponseObject> translations;

}

和

@XmlAccessorType(XmlAccessType.FIELD)
@Getter
@Setter
@ToString
public class TranslatedResponseObject {

    @XmlElement(name="TranslatedText")
    private String translatedText;


}

通过解组提供的 xml 示例，我收到了字段翻译的 null。怎么了？

Answer 1

感谢@klonq 提出的调试问题的建议，我已经找到了解决方案。必须在每个@XmlElement 和@XmlRootElement 上添加命名空间，这样：

@XmlRootElement(name="ArrayOfTranslateArrayResponse", namespace="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2")
@XmlAccessorType(XmlAccessType.FIELD)
@Getter
@Setter
@ToString
public class TranslateResponse {

    @XmlElement(name="TranslateArrayResponse", namespace="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2")
    private LinkedList<TranslatedResponseObject> translations;

}

@XmlAccessorType(XmlAccessType.FIELD)
@Getter
@Setter
@ToString
public class TranslatedResponseObject {

    @XmlElement(name="TranslatedText", namespace="http://schemas.datacontract.org/2004/07/Microsoft.MT.Web.Service.V2")
    private String translatedText;


}

Answer 2

您可以使用 ValidationEventHandler 来调试问题。

public class MyValidationEventHandler implements ValidationEventHandler {

    @Override
    public boolean handleEvent(ValidationEvent event) {

        switch (event.getSeverity()) {

            case ValidationEvent.WARNING: 
            case ValidationEvent.ERROR: 
            case ValidationEvent.FATAL_ERROR: {
                log.error("Validation event : {} in {} line {} col {}",
                          event.getMessage(),
                          event.getLocator().getURL(),
                          event.getLocator().getLineNumber(),
                          event.getLocator().getColumnNumber());
                return false;
            }
            default:
                return true;
        }
    }
}

你可以像下面这样使用它：

final JAXBContext jAXBContext = JAXBContext.newInstance(target);
final Unmarshaller unmarshaller = jAXBContext.createUnmarshaller();

unmarshaller.setEventHandler(new MyValidationEventHandler());

unmarshaller.unmarshal(file);