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 * accompanied this code).

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package com.sun.tools.internal.xjc.reader.xmlschema.parser;

import com.sun.tools.internal.xjc.reader.Const;

import com.sun.xml.internal.bind.v2.WellKnownNamespace;

import org.xml.sax.Attributes;

import org.xml.sax.ErrorHandler;

import org.xml.sax.Locator;

import org.xml.sax.SAXException;

import org.xml.sax.SAXParseException;

import org.xml.sax.helpers.XMLFilterImpl;

/**

 * This filter detects the use of incorrect JAXB namespace URI.

 *

 * When the binding compiler looks at a schema file, it always look

 * for the namespace URI of the elements (which is correct, BTW.)

 *

 * <p>

 * However, one unfortunate downside of this philosophically correct

 * behavior is that there is no provision or safety check when an user

 * misspelled JAXB binding customization namespace.

 *

 * <p>

 * This checker inspects the input document and look for the use of the

 * prefix "jaxb". If the document doesn't associate any prefix to the

 * JAXB customization URI and if it does associate the jaxb prefix,

 * this checker will issue a warning.

 *

 * <p>

 * This warning can happen to completely correct schema (because

 * nothing prevents you from using the prefix "jaxb" for other purpose

 * while using a JAXB compiler on the same schema) but in practice

 * this would be quite unlikely.

 *

 * <p>

 * This justifies the use of this filter.

 *

 * @author

 *     Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)

 */

public class IncorrectNamespaceURIChecker extends XMLFilterImpl {

    public IncorrectNamespaceURIChecker( ErrorHandler handler ) {

        this.errorHandler = handler;

    }

    private ErrorHandler errorHandler;

    private Locator locator = null;

    /** Sets to true once we see the jaxb prefix in use. */

    private boolean isJAXBPrefixUsed = false;

    /** Sets to true once we see the JAXB customization namespace URI. */

    private boolean isCustomizationUsed = false;

    @Override

    public void endDocument() throws SAXException {

        if( isJAXBPrefixUsed && !isCustomizationUsed ) {

            SAXParseException e = new SAXParseException(

                Messages.format(Messages.WARN_INCORRECT_URI, Const.JAXB_NSURI),

                locator );

            errorHandler.warning(e);

        }

        super.endDocument();

    }

    @Override

    public void startPrefixMapping(String prefix, String uri) throws SAXException {

        if (WellKnownNamespace.XML_NAMESPACE_URI.equals(uri)) return; //xml prefix shall not be declared based on jdk api javadoc

        if( prefix.equals("jaxb") )

            isJAXBPrefixUsed = true;

        if( uri.equals(Const.JAXB_NSURI) )

            isCustomizationUsed = true;

        super.startPrefixMapping(prefix, uri);

    }

    @Override

    public void endPrefixMapping(String prefix) throws SAXException {

        if ("xml".equals(prefix)) return; //xml prefix shall not be declared based on jdk api javadoc

        super.endPrefixMapping(prefix);

    }

    @Override

    public void startElement(String namespaceURI, String localName, String qName, Attributes atts)

        throws SAXException {

        super.startElement(namespaceURI, localName, qName, atts);

        // I'm not sure if this is necessary (SAX might report the change of the default prefix

        // through the startPrefixMapping method, and I think it does indeed.)

        //

        // but better safe than sorry.

        if( namespaceURI.equals(Const.JAXB_NSURI) )

            isCustomizationUsed = true;

    }

    @Override

    public void setDocumentLocator( Locator locator ) {

        super.setDocumentLocator( locator );

        this.locator = locator;

    }

}