JAXB反序列化时Timestamp类型XmlAdapter失效问题排查

尝试将给定XML反序列化为Java对象时，所有字段均正常赋值，仅timeStamp字段例外。已编写自定义XmlAdapter用于解析Timestamp，但调试时从未进入该适配器，字段始终无法被赋值。

示例XML #

<RootElement>
    <Id>4</Id>
    <Number>628</Number>
    <rId>110080110</rId>
    <OrderNmbr>1234</OrderNmbr>
    <Responses>
        <Response>
            <Date>2016-10-21T12:56:19.549+05:30</Date>
            <Premium>1232131</Premium>
            <Income>1231232</Income>
            <E1>251345</E1>
            <E2>7645233</E2>
            <Tags>
                <Tag>
                    <timeStamp xsi:type="java:java.lang.String" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">1970-01-10 02:07:36.453</timeStamp>
                    <Cd>3425235</Cd>
                    <Cd1>1</Cd1>
                    <ValText>1</ValText>
                    <TokenId>1234</TokenId>
                </Tag>
                <Tag>
                    <timeStamp xsi:type="java:java.lang.String" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">1970-01-10 02:07:36.453</timeStamp>
                    <Cd>3425236</Cd>
                    <Cd1>2</Cd1>
                    <ValText>2</ValText>
                    <TokenId>1235</TokenId>
                </Tag>
            </Tags>
        </Response>
    </Responses>
</RootElement>

项目中的Java类 #

ExampleClass #

@XmlRootElement(name = "RootElement")
public class ExampleClass {

    @XmlElement(name = "Id")
    protected String pId;
    @XmlElement(name = "Number")
    protected Integer cNumber;
    protected Integer rId;
    protected String orderNmbr;
    @XmlElementWrapper(name = "responses")
    @XmlElement(name = "Response")
    protected List<Response> responses;
    
    // Getters and setters
    
    public class Response {

        protected Date date;                    
        protected BigDecimal premium;       
        protected BigDecimal income;            
        protected BigDecimal e1;                    
        protected BigDecimal e2;                    
        protected List<Tag> tags;
        
        // Getters and setters
        
        public class Tag {

            @XmlElement(name = "timeStamp", namespace = "http://www.w3.org/2001/XMLSchema-instance", type =  String.class)
            @XmlJavaTypeAdapter(CustomTimeStampAdapter.class)
            protected Timestamp timeStamp;
            protected Integer cd;
            protected Integer cd1;
            protected String valText;
            protected String tokenId;
            
            // Getters and setters
        }
    }
}

自定义XmlAdapter #

public class CustomTimeStampAdapter extends XmlAdapter<String, Timestamp> {

    /**
     * Convert a value type to a bound type.
     *
     * @param timeStamp The value to be converted. Can be null.
     * @throws Exception if there's an error during the conversion. The caller is responsible for
     *                   reporting the error to the user through {@link ValidationEventHandler}.
     */
    @Override
    public Timestamp unmarshal(String timeStamp) throws Exception {
        if (StringUtils.isBlank(timeStamp)) {
            return null;
        }
        return Timestamp.valueOf(timeStamp.trim());
    }

    /**
     * Convert a bound type to a value type.
     *
     * @param timeStamp The value to be converted. Can be null.
     * @throws Exception if there's an error during the conversion. The caller is responsible for
     *                   reporting the error to the user through {@link ValidationEventHandler}.
     */
    @Override
    public String marshal(Timestamp timeStamp) throws Exception {
        return timeStamp.toString();
    }
}

JAXB配置Bean #

@Bean(name = "jaxb2Marshaller")
public Jaxb2Marshaller getJaxb2Marshaller() {
    Jaxb2Marshaller jaxb2Marshaller = new Jaxb2Marshaller();
    jaxb2Marshaller.setClassesToBeBound(
            //all the classes the context needs to know about
       ExampleClass.class, Response.class, Tag.class);

    return jaxb2Marshaller;
}

排查更新 #

测试发现，移除timeStamp节点中的xsi:type="java:java.lang.String" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"属性后，调试器能正常进入CustomTimeStampAdapter，字符串可成功转换为Timestamp类型。确认问题与命名空间相关，正在进一步排查。

内容的提问来源于stack exchange，提问作者Lucky