如何配置JAXB / Moxy以在XML中丢失潜在的丢失数据错误 [英] How to configure JAXB / Moxy to throw an error on potential lost data in XML

问题描述

如果提供的数据不能解组到预期的数据类型中，是否可以将JAXB配置为抛出异常？

Is it possible to configure JAXB to throw an exception if the supplied data is not unmarshalable into the expected data type?

我们有一个Integer XmlElement，有时会得到值比如1.1作为输入 - Jaxb / Moxy只是默默地忽略这些值并将它们设置为null。我们通过使用舍入这些值的@XmlJavaTypeAdapter解决了已知情况，但是我们不知道是否有任何其他字段在错误数据上被忽略，并且更喜欢异常以获得清晰的反馈。

We have a Integer XmlElement and sometimes get values like "1.1" as input - Jaxb / Moxy just silently ignores these values and sets them to null. We solved it for the known cases by using a @XmlJavaTypeAdapter that rounds those values, but we won't know if any other fields get silently ignored on wrong data and would prefer a exception for clear feedback.

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class Wrapper
{
    @XmlNullPolicy(emptyNodeRepresentsNull = true, nullRepresentationForXml = XmlMarshalNullRepresentation.EMPTY_NODE)
    private Integer emptyNodeOnNull;

    @XmlElement
    private Integer ignoredOnNull;
}

以下测试应该抛出某种异常..

The following test should throw some kind of exception..

@Test(expected = IllegalArgumentException.class)
public void testUnmarshallWithInvalidValue() throws Exception
{
    JAXBContext context = JAXBContext.newInstance(Wrapper.class);
    StreamSource source = new StreamSource(
            new StringReader(
                    "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?><wrapper><emptyNodeOnNull>1.1</emptyNodeOnNull><ignoredOnNull>2.2</ignoredOnNull></wrapper>"));
    context.createUnmarshaller().unmarshal(source, Wrapper.class);

    fail("Should have thrown some kind of exception due to lost data.");
}

我们现在使用Moxy 2.5.2 for JAXB，因为我们需要@ XmlNullPolicy（emptyNodeRepresentsNull = true，nullRepresentationForXml = XmlMarshalNullRepresentation.EMPTY_NODE）。

We use Moxy 2.5.2 for JAXB right now, as we need the @XmlNullPolicy(emptyNodeRepresentsNull = true, nullRepresentationForXml = XmlMarshalNullRepresentation.EMPTY_NODE).

推荐答案

您可以设置的实例在此类问题上收集失败的 Unmarshaller 上的ValidationEventHandler 。

You can set an instance of ValidationEventHandler on the Unmarshaller to collect of fail on this type of issue.

public class DeserializationEventHandler implements ValidationEventHandler
{
private static final Logger LOG = LoggerFactory.getLogger(DeserializationEventHandler.class);

@Override
public boolean handleEvent(ValidationEvent event)
{
    LOG.warn("Error during XML conversion: {}", event);

    if (event.getLinkedException() instanceof NumberFormatException)
        return false;

    return true;
}

}

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