JAXB: when using XML schema (.xsd) to validate an XML file, if validation fail, can I know which XML tag causing it?

Question

so right now when I validate the XML file using an XML schema, I am only able to know whether it fail or pass, and if I want to know why it fail, I need to look at the error message like

[org.xml.sax.SAXParseException: cvc-complex-type.2.4.a: Invalid content was found starting with element 'City'. One of '{Address1}' is expected.]

In the above example, it fail because I am missing tag Address1. My question is When the validation fail, can I know which tag causing the failure? This is because I need to handle these failure differently for each important missing-tag. Right now my thought is

FileInputStream inputStream = null;
try{
    SchemaFactory sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
    Schema schema = sf.newSchema(new File(config.getXmlSchema()));
    JAXBContext context = JAXBContext.newInstance(PackageLabel.class);
    Unmarshaller unmarshaller = context.createUnmarshaller();
    unmarshaller.setSchema(schema);
    inputStream = new FileInputStream(xmlFile);
    pl = (PackageLabel) unmarshaller.unmarshal(inputStream);
} catch (JAXBException e) {
    if(pl.getAddress1() == null){
         System.out.println("Invalid Mailing Address");
    }
    //EDIT: CANNOT DO THIS, SINCE pl  IS NULL AT THIS POINT
    //Some more logics on how to handle important missing-tags
    ...
}finally{
    if(inputStream != null) inputStream.close();
}  

However, I do not think writing logic inside catch clause is correct. Any advice?

EDIT

I followed Balaise idea, and below is the event I received when the XML missing an Address1

EVENT
SEVERITY:  2
MESSAGE:  cvc-complex-type.2.4.a: Invalid content was found starting with element 'City'. One of '{Address1}' is expected.
LINKED EXCEPTION:  org.xml.sax.SAXParseException: cvc-complex-type.2.4.a: Invalid content was found starting with element 'City'. One of '{Address1}' is expected.
LOCATOR
 LINE NUMBER:  4
 COLUMN NUMBER:  11
 OFFSET:  -1
 OBJECT:  null
 NODE:  null
 URL:  null

However, both NODE and OBJECT are null, I cannot further investigate on what causing the exception unless I parse the exception which is what I asked originally.

Answer 1

You can leverage JAXB's ValidationEventHandler for this. An implementation can then be set on instances of Marshaller and Unmarshaller:

package blog.jaxb.validation;

import javax.xml.bind.ValidationEvent;
import javax.xml.bind.ValidationEventHandler;

public class MyValidationEventHandler implements ValidationEventHandler {

    public boolean handleEvent(ValidationEvent event) {
        System.out.println("\nEVENT");
        System.out.println("SEVERITY:  " + event.getSeverity());
        System.out.println("MESSAGE:  " + event.getMessage());
        System.out.println("LINKED EXCEPTION:  " + event.getLinkedException());
        System.out.println("LOCATOR");
        System.out.println("    LINE NUMBER:  " + event.getLocator().getLineNumber());
        System.out.println("    COLUMN NUMBER:  " + event.getLocator().getColumnNumber());
        System.out.println("    OFFSET:  " + event.getLocator().getOffset());
        System.out.println("    OBJECT:  " + event.getLocator().getObject());
        System.out.println("    NODE:  " + event.getLocator().getNode());
        System.out.println("    URL:  " + event.getLocator().getURL());
        return true;
    }

}

For More Information

• http://blog.bdoughan.com/2010/12/jaxb-and-marshalunmarshal-schema.html
• http://bdoughan.blogspot.com/2010/11/validate-jaxb-object-model-with-xml.html