jaxb - how to know when eventhandler is called (during validation) - jaxb

Question

I am parsing XML with JAXB and have created an event handler that will display errors if there were issues on validation.
The event handler is called and prints out errors; How do I throw an exception if the event handler is called (after printout?)
In the code, I have no idea when the event handler is called, it is simply called on a validation error; I need the ability to move a file to a /dir/ after the event handler returns.
My event handler looks like this:
import base.helper.HelperBase;
import org.springframework.stereotype.Component;
import javax.xml.bind.ValidationEvent;
import javax.xml.bind.ValidationEventHandler;
import java.util.logging.Level;
/**
*
*/
#Component
public class MyValidationEventHandler extends HelperBase implements ValidationEventHandler {
public boolean handleEvent(ValidationEvent event) {
logger.log(Level.INFO, "\n---");
System.out.println("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());
new Exception("fail");
return true;
}
}
When processing, my code looks like this:
private void processXmlFile(String file) throws Exception {
// todo: test for file existence, get size, print stats
try {
logger.log(Level.INFO, "Processing: " + file);
SchemaFactory sf = null;
Schema schema = null;
JAXBContext jctx = JAXBContext.newInstance("mypackage.jaxb");
Unmarshaller unmarshaller = jctx.createUnmarshaller();
if (validate) {
sf = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
schema = sf.newSchema(new File(xsd));
unmarshaller.setSchema(schema);
eventHandler.setLogger(logger);
unmarshaller.setEventHandler(eventHandler);
}
JAXBElement<MyType> mytype = unmarshaller.unmarshal(new StreamSource(new File(file)), MyType.class);
MyType ct = mytype.getValue();
} catch (Exception e) { // if find a problem file, just move it out of the way and keep processing
// if the event handler is called, I want to throw an exception and do something here.
// move file to failed
fileUtils.moveFile(config.getErrorDir(), file);
// on an unmarshall failure, this exception is not thrown/caught because the event handler handles things and returns true
}
}

Answer 1

Please read How to Throw Exceptions.
In your event handler you need to throw() an Exception perhaps with something like:
throw new ValidationException(); // throw exeption
Instead of:
new Exception("fail"); // create exception but do nothing with it?
And you would define your ValidationException as:
public class ValidationException extends RuntimeException {
public ValidationException(final String s) {
super(s);
}
Change:
public boolean handleEvent(ValidationEvent event) {
To:
public boolean handleEvent(ValidationEvent event) throws ValidationException {
In processXmlFile() we now need something like:
catch (ValidationException e) {
// catch more specific exception first
fileUtils.moveFile(config.getErrorDir(), file);
catch (Exception e) {
// deal with any other exceptions ...
}