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package com.sun.tools.internal.xjc.reader.internalizer;

import java.io.IOException;

import com.sun.xml.internal.xsom.parser.XMLParser;

import org.w3c.dom.Document;
import org.xml.sax.ContentHandler;
import org.xml.sax.EntityResolver;
import org.xml.sax.ErrorHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;


XMLParser implementation that parses XML from a DOM forest instead of parsing it from its original location. 
Author:

    Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)/**
 * {@link XMLParser} implementation that
 * parses XML from a DOM forest instead of parsing it from
 * its original location.
 *
 * @author
 *     Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
 */
class DOMForestParser implements XMLParser {

    
DOM forest to be "parsed". /** DOM forest to be "parsed". */
    private final DOMForest forest;

    
Scanner object will do the actual SAX events generation. /** Scanner object will do the actual SAX events generation. */
    private final DOMForestScanner scanner;

    private final XMLParser fallbackParser;

    
Params:
fallbackParser – 
     This parser will be used when DOMForestParser needs to parse
     documents that are not in the forest./**
     * @param fallbackParser
     *      This parser will be used when DOMForestParser needs to parse
     *      documents that are not in the forest.
     */
    DOMForestParser( DOMForest forest, XMLParser fallbackParser ) {
        this.forest = forest;
        this.scanner = new DOMForestScanner(forest);
        this.fallbackParser = fallbackParser;
    }

    public void parse(
        InputSource source,
        ContentHandler contentHandler,
        ErrorHandler errorHandler,
        EntityResolver entityResolver )
        throws SAXException, IOException {

        String systemId = source.getSystemId();
        Document dom = forest.get(systemId);

        if(dom==null) {
            // if no DOM tree is built for it,
            // let the fall back parser parse the original document.
            //
            // for example, XSOM parses datatypes.xsd (XML Schema part 2)
            // but this will never be built into the forest.
            fallbackParser.parse( source, contentHandler, errorHandler, entityResolver );
            return;
        }

        scanner.scan( dom, contentHandler );
    }
}