/*
* XMLEntityResolver.java NanoXML/Java $Revision: 1.4 $ $Date: 2002/01/04
* 21:03:29 $ $Name: RELEASE_2_2_1 $ This file is part of NanoXML 2 for Java.
* Copyright (C) 2000-2002 Marc De Scheemaecker, All Rights Reserved. This
* software is provided 'as-is', without any express or implied warranty. In no
* event will the authors be held liable for any damages arising from the use of
* this software. Permission is granted to anyone to use this software for any
* purpose, including commercial applications, and to alter it and redistribute
* it freely, subject to the following restrictions: 1. The origin of this
* software must not be misrepresented; you must not claim that you wrote the
* original software. If you use this software in a product, an acknowledgment
* in the product documentation would be appreciated but is not required. 2.
* Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software. 3. This notice may not be
* removed or altered from any source distribution.
*/
package org.freeplane.n3.nanoxml;
import java.io.Reader;
import java.io.StringReader;
import java.util.Hashtable;
/**
* An XMLEntityResolver resolves entities.
*
* @author Marc De Scheemaecker
* @version $Name: RELEASE_2_2_1 $, $Revision: 1.4 $
*/
class XMLEntityResolver implements IXMLEntityResolver {
/**
* The entities.
*/
private Hashtable<String, Object> entities;
/**
* Initializes the resolver.
*/
public XMLEntityResolver() {
entities = new Hashtable<String, Object>();
entities.put("amp", "&");
entities.put("quot", """);
entities.put("apos", "'");
entities.put("lt", "<");
entities.put("gt", ">");
}
/**
* Adds an external entity.
*
* @param name
* the name of the entity.
* @param publicID
* the public ID of the entity, which may be null.
* @param systemID
* the system ID of the entity.
*/
public void addExternalEntity(final String name, final String publicID, final String systemID) {
if (!entities.containsKey(name)) {
entities.put(name, new String[] { publicID, systemID });
}
}
/**
* Adds an internal entity.
*
* @param name
* the name of the entity.
* @param value
* the value of the entity.
*/
public void addInternalEntity(final String name, final String value) {
if (!entities.containsKey(name)) {
entities.put(name, value);
}
}
/**
* Cleans up the object when it's destroyed.
*/
@Override
protected void finalize() throws Throwable {
entities.clear();
entities = null;
super.finalize();
}
/**
* Returns a Java reader containing the value of an entity.
*
* @param xmlReader
* the current XML reader
* @param name
* the name of the entity.
* @return the reader, or null if the entity could not be resolved.
*/
public Reader getEntity(final IXMLReader xmlReader, final String name) throws XMLParseException {
final Object obj = entities.get(name);
if (obj == null) {
return null;
}
else if (obj instanceof java.lang.String) {
return new StringReader((String) obj);
}
else {
final String[] id = (String[]) obj;
return this.openExternalEntity(xmlReader, id[0], id[1]);
}
}
/**
* Returns true if an entity is external.
*
* @param name
* the name of the entity.
*/
public boolean isExternalEntity(final String name) {
final Object obj = entities.get(name);
return !(obj instanceof java.lang.String);
}
/**
* Opens an external entity.
*
* @param xmlReader
* the current XML reader
* @param publicID
* the public ID, which may be null
* @param systemID
* the system ID
* @return the reader, or null if the reader could not be created/opened
*/
protected Reader openExternalEntity(final IXMLReader xmlReader, final String publicID, final String systemID)
throws XMLParseException {
final String parentSystemID = xmlReader.getSystemID();
try {
return xmlReader.openStream(publicID, systemID);
}
catch (final Exception e) {
throw new XMLParseException(parentSystemID, xmlReader.getLineNr(), "Could not open external entity "
+ "at system ID: " + systemID);
}
}
}