dtdentityresolver.java

java 写的一个新闻发布系统

//
//                                   ____.
//                       __/\ ______|    |__/\.     _______
//            __   .____|    |       \   |    +----+       \
//    _______|  /--|    |    |    -   \  _    |    :    -   \_________
//   \\______: :---|    :    :           |    :    |         \________>
//           |__\---\_____________:______:    :____|____:_____\
//                                      /_____|
//
//                 . . . i n   j a h i a   w e   t r u s t . . .
//
//
//
//  DtdEntityResolver
//
//  NK    08.03.2001
//

package org.jahia.utils.xml;


import java.io.*;
import java.util.*;
import org.w3c.dom.*;


import org.jahia.exceptions.*;
import org.jahia.utils.*;               // JahiaConsole

import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;


import org.jahia.data.constants.JahiaConstants;


/**
 * Substitute external DTD files with local DTD files.
 *
 * @author Khue
 * @version 1.0
 */
public class DtdEntityResolver implements EntityResolver {

	/**
     * Registered DTD, the key is the public id
     */
    private Hashtable m_DTDs = new Hashtable();
   	

   	/**
	 * Replace external dtd with local dtd.
	 * Return an InputSource to a local DTD file or null if not found
	 * in the registered DTD
	 * 
	 */
	public InputSource resolveEntity (String publicID, String systemID) {

		//System.out.println("DtdEntityResolver: " + publicID + " " + systemID);

		if ( publicID == null ){
			return null;
		}
		
		String dtd = null;
				
		if ( m_DTDs.get(publicID) != null ){
			dtd = (String) m_DTDs.get(publicID);
		}
		
		if( dtd != null ) {
			//System.out.println("DtdEntityResolver: found dtd ");
	    	File f = new File( dtd );
	    	if( f.exists() )
			try {
		    	return new InputSource(new FileInputStream(f));
			} catch( FileNotFoundException ex ) {
			}
		}

   		return null;
   	}


    /**
     *
     * @param publicID the key to identify the requested dtd
     * @param dtd the dtd resource file
     */
    public void registerDTD(String publicID, String dtd) {
	
		m_DTDs.put(publicID, dtd);

    }


}