/* SAXAdapter.java NanoXML/SAX
*
* $Revision: 1.4 $
* $Date: 2002/01/04 21:03:28 $
* $Name: RELEASE_2_2_1 $
*
* This file is part of the SAX adapter for 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 net.n3.nanoxml.sax;
import java.io.Reader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.MalformedURLException;
import net.n3.nanoxml.IXMLBuilder;
import net.n3.nanoxml.IXMLReader;
import org.xml.sax.AttributeList;
import org.xml.sax.DocumentHandler;
import org.xml.sax.ErrorHandler;
import org.xml.sax.HandlerBase;
import org.xml.sax.Locator;
import org.xml.sax.helpers.AttributeListImpl;
import org.xml.sax.helpers.LocatorImpl;
/**
* SAXAdapter is the core adapter for using NanoXML/Java with SAX, the "Simple"
* API For XML.
*
* @see net.n3.nanoxml.IXMLBuilder
*
* @author Marc De Scheemaecker
* @version $Name: RELEASE_2_2_1 $, $Revision: 1.4 $
*/
public class SAXAdapter
implements IXMLBuilder
{
/**
* The NanoXML reader.
*/
private IXMLReader nanoxmlReader;
/**
* The SAX document handler.
*/
private DocumentHandler saxDocumentHandler;
/**
* The SAX error handler.
*/
private ErrorHandler saxErrorHandler;
/**
* The SAX locator.
*/
private LocatorImpl saxLocator;
/**
* The SAX attribute list.
*/
private AttributeListImpl saxAttributes;
/**
* Creates the adapter.
*/
public SAXAdapter()
{
this.saxDocumentHandler = new HandlerBase();
this.saxLocator = new LocatorImpl();
this.saxLocator.setColumnNumber(-1);
}
/**
* Cleans up the object when it's destroyed.
*/
protected void finalize()
throws Throwable
{
this.nanoxmlReader = null;
this.saxDocumentHandler = null;
this.saxErrorHandler = null;
this.saxLocator = null;
this.saxAttributes = null;
super.finalize();
}
/**
* Sets the document handler.
*
* @param handler the document handler
*/
public void setDocumentHandler(DocumentHandler handler)
{
this.saxDocumentHandler = handler;
}
/**
* Sets the reader.
*
* @param reader the reader.
*/
public void setReader(IXMLReader reader)
{
this.nanoxmlReader = reader;
}
/**
* This method is called before the parser starts processing its input.
*
* @param systemID the system ID of the data source
* @param lineNr the line on which the parsing starts
*/
public void startBuilding(String systemID,
int lineNr)
throws Exception
{
this.saxLocator.setLineNumber(lineNr);
this.saxLocator.setSystemId(systemID);
this.saxDocumentHandler.setDocumentLocator(this.saxLocator);
this.saxDocumentHandler.startDocument();
}
/**
* This method is called when a processing instruction is encountered.
* PIs with target "xml" are handled by the parser.
*
* @param target the PI target
* @param reader to read the data from the PI
*/
public void newProcessingInstruction(String target,
Reader reader)
throws Exception
{
StringBuffer data = new StringBuffer();
char[] chars = new char[1024];
int charsRead = reader.read(chars);
while (charsRead > 0) {
data.append(chars, 0, charsRead);
charsRead = reader.read(chars);
}
this.saxDocumentHandler.processingInstruction(target, data.toString());
}
/**
* This method is called when a new XML element is encountered.
*
* @see #endElement
*
* @param name the name of the element
* @param nsPrefix the prefix used to identify the namespace
* @param nsSystemId the system ID associated with the namespace
* @param systemID the system ID of the data source
* @param lineNr the line in the source where the element starts
*/
public void startElement(String name,
String nsPrefix,
String nsSystemId,
String systemID,
int lineNr)
throws Exception
{
if (nsPrefix != null) {
name = nsPrefix + ':' + name;
}
this.saxLocator.setLineNumber(lineNr);
this.saxLocator.setSystemId(systemID);
this.saxAttributes = new AttributeListImpl();
}
/**
* This method is called when the attributes of an XML element have been
* processed.
*
* @see #startElement
* @see #addAttribute
*
* @param name the name of the element
* @param nsPrefix the prefix used to identify the namespace
* @param nsSystemId the system ID associated with the namespace
*/
public void elementAttributesProcessed(String name,
String nsPrefix,
String nsSystemId)
throws Exception
{
if (nsPrefix != null) {
name = nsPrefix + ':' + name;
}
this.saxDocumentHandler.startElement(name, this.saxAttributes);
}
/**
* This method is called when the end of an XML elemnt is encountered.
*
* @see #startElement
*
* @param name the name of the element
* @param nsPrefix the prefix used to identify the namespace
* @param nsSystemId the system ID associated with the namespace
*/
public void endElement(String name,
String nsPrefix,
String nsSystemId)
throws Exception
{
if (nsPrefix != null) {
name = nsPrefix + ':' + name;
}
this.saxDocumentHandler.endElement(name);
}
/**
* This method is called when a new attribute of an XML element is
* encountered.
*
* @param key the key (name) of the attribute
* @param nsPrefix the prefix used to identify the namespace
* @param nsSystemId the system ID associated with the namespace
* @param value the value of the attribute
* @param type the type of the attribute ("CDATA" if unknown)
*/
public void addAttribute(String key,
String nsPrefix,
String nsSystemId,
String value,
String type)
throws Exception
{
if (nsPrefix != null) {
key = nsPrefix + ':' + key;
}
this.saxAttributes.addAttribute(key, type, value);
}
/**
* This method is called when a PCDATA element is encountered. A Java
* reader is supplied from which you can read the data. The reader will
* only read the data of the element. You don't need to check for
* boundaries. If you don't read the full element, the rest of the data
* is skipped. You also don't have to care about entities; they are
* resolved by the parser.
*
* @param reader the Java reader from which you can retrieve the data
* @param systemID the system ID of the data source
* @param lineNr the line in the source where the element starts
*
* @throws java.io.IOException
* when the reader throws such exception
*/
public void addPCData(Reader reader,
String systemID,
int lineNr)
throws Exception
{
this.saxLocator.setLineNumber(lineNr);
this.saxLocator.setSystemId(systemID);
char[] chars = new char[2048];
int charsRead = reader.read(chars);
while (charsRead > 0) {
this.saxDocumentHandler.characters(chars, 0, charsRead);
charsRead = reader.read(chars);
}
}
/**
* Returns the result of the building process. This method is called just
* before the parse() method of IXMLParser returns.
*
* @see net.n3.nanoxml.IXMLParser#parse
*
* @return the result of the building process.
*/
public Object getResult()
throws Exception
{
return null;
}
/**
* Indicates that parsing has been completed.
*/
public void endDocument()
throws Exception
{
this.saxDocumentHandler.endDocument();
}
}