defaultvalidationeventhandler.java

java1.6众多例子参考

/*
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package javax.xml.bind.helpers;

import org.w3c.dom.Node;

import javax.xml.bind.ValidationEvent;
import javax.xml.bind.ValidationEventHandler;
import javax.xml.bind.ValidationEventLocator;
import java.net.URL;

/**
 * <p>
 * JAXB 1.0 only default validation event handler. This is the default 
 * handler for all objects created from a JAXBContext that is managing
 * schema-derived code generated by a JAXB 1.0 binding compiler. 
 *
 * <p>
 * This handler causes the unmarshal and validate operations to fail on the first
 * error or fatal error.
 * 
 * <p>
 * This handler is not the default handler for JAXB mapped classes following 
 * JAXB 2.0 or later versions. Default validation event handling has changed 
 * and is specified in  {@link javax.xml.bind.Unmarshaller} and 
 * {@link javax.xml.bind.Marshaller}.
 *
 * @author <ul><li>Ryan Shoemaker, Sun Microsystems, Inc.</li></ul>
 * @version $Revision: 1.4 $
 * @see javax.xml.bind.Unmarshaller
 * @see javax.xml.bind.Validator
 * @see javax.xml.bind.ValidationEventHandler
 * @since JAXB1.0
 */
public class DefaultValidationEventHandler implements ValidationEventHandler {
    
    public boolean handleEvent( ValidationEvent event ) {
        
        if( event == null ) {
            throw new IllegalArgumentException();
        }

        // calculate the severity prefix and return value        
        String severity = null;
        boolean retVal = false;
        switch ( event.getSeverity() ) {
            case ValidationEvent.WARNING:
                severity = Messages.format( Messages.WARNING );
                retVal = true; // continue after warnings
                break;
            case ValidationEvent.ERROR:
                severity = Messages.format( Messages.ERROR );
                retVal = false; // terminate after errors
                break;
            case ValidationEvent.FATAL_ERROR:
                severity = Messages.format( Messages.FATAL_ERROR );
                retVal = false; // terminate after fatal errors
                break;
            default:
                assert false :
                    Messages.format( Messages.UNRECOGNIZED_SEVERITY,
                            event.getSeverity() );
        }
        
        // calculate the location message
        String location = getLocation( event );
        
        System.out.println( 
            Messages.format( Messages.SEVERITY_MESSAGE,
                             severity,
                             event.getMessage(),
                             location ) );
        
        // fail on the first error or fatal error
        return retVal;
    }

    /**
     * Calculate a location message for the event
     * 
     */
    private String getLocation(ValidationEvent event) {
        StringBuffer msg = new StringBuffer();
        
        ValidationEventLocator locator = event.getLocator();
        
        if( locator != null ) {
            
            URL url = locator.getURL();
            Object obj = locator.getObject();
            Node node = locator.getNode();
            int line = locator.getLineNumber();
            
            if( url!=null || line!=-1 ) {
                msg.append( "line " + line );
                if( url!=null )
                    msg.append( " of " + url );
            } else if( obj != null ) {
                msg.append( " obj: " + obj.toString() );
            } else if( node != null ) {
                msg.append( " node: " + node.toString() );
            }
        } else {
            msg.append( Messages.format( Messages.LOCATION_UNAVAILABLE ) );
        } 
        
        return msg.toString();
    }
}