JAXB does not call setter when unmarshalling objects

Question

I am using JAXB 2.0 JDK 6 in order to unmarshall an XML instance into POJOs.

In order to add some custom validation I have inserted a validation call into the setter of a property, yet despite it being private, it seems that the unmarshaller does not call the setter but directly modifies the private field.

It is crucial to me that the custom validation occurs for this specific field every unmarshall call.

What should I do?

Code:

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "LegalParams", propOrder = {
    "value"
})
public class LegalParams {

    private static final Logger LOG = Logger.getLogger(LegalParams.class);

    @XmlTransient
    private LegalParamsValidator legalParamValidator;

    public LegalParams() {

        try {
            WebApplicationContext webApplicationContext = ContextLoader.getCurrentWebApplicationContext();
            LegalParamsFactory legalParamsFactory = (LegalParamsFactory) webApplicationContext.getBean("legalParamsFactory");
            HttpSession httpSession = SessionHolder.getInstance().get();
            legalParamValidator = legalParamsFactory.newLegalParamsValidator(httpSession);
        }
        catch (LegalParamsException lpe) {
            LOG.warn("Validator related error occurred while attempting to construct a new instance of LegalParams");
            throw new IllegalStateException("LegalParams creation failure", lpe);
        }
        catch (Exception e) {
            LOG.warn("Spring related error occurred while attempting to construct a new instance of LegalParams");
            throw new IllegalStateException("LegalParams creation failure", e);
        }
    }

    @XmlValue
    private String value;

    /**
     * Gets the value of the value property.
     *
     * @return
     *     possible object is
     *     {@link String }
     *
     */
    public String getValue() {
        return value;
    }

    /**
     * Sets the value of the value property.
     *
     * @param value
     *     allowed object is
     *     {@link String }
     * @throws TestCaseValidationException
     *
     */
    public void setValue(String value) throws TestCaseValidationException {
        legalParamValidator.assertValid(value);
        this.value = value;
    }
}

Answer 1

JAXB uses field access because you configured it to use field access by annotating a field with @XmlValue and by declaring @XmlAccessorType(XmlAccessType.FIELD).

To use property access, you can move @XmlValue to either getter or setter (@XmlAccessorType is not needed at all).