/*
* StdXMLBuilder.java NanoXML/Java $Revision: 1.3 $ $Date: 2002/01/04 21:03:28 $
* $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.IOException;
import java.io.Reader;
import java.util.Stack;
/**
* StdXMLBuilder is a concrete implementation of IXMLBuilder which creates a
* tree of IXMLElement from an XML data source.
*
* @see org.freeplane.n3.nanoxml.XMLElement
* @author Marc De Scheemaecker
* @version $Name: RELEASE_2_2_1 $, $Revision: 1.3 $
*/
class StdXMLBuilder implements IXMLBuilder {
/**
* Prototype element for creating the tree.
*/
private XMLElement prototype;
/**
* The root element of the parsed XML tree.
*/
private XMLElement root;
/**
* This stack contains the current element and its parents.
*/
private Stack<XMLElement> stack;
/**
* Creates the builder.
*/
public StdXMLBuilder() {
this(new XMLElement());
}
/**
* Creates the builder.
*
* @param prototype
* the prototype to use when building the tree.
*/
public StdXMLBuilder(final XMLElement prototype) {
stack = null;
root = null;
this.prototype = prototype;
}
/**
* 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. If no namespace has
* been specified, this parameter is null.
* @param nsURI
* the URI associated with the namespace. If no namespace has
* been specified, or no URI is associated with nsPrefix, this
* parameter is null.
* @param value
* the value of the attribute.
* @param type
* the type of the attribute. If no type is known, "CDATA" is
* returned.
* @throws java.lang.Exception
* If an exception occurred while processing the event.
*/
public void addAttribute(final String key, final String nsPrefix, final String nsURI, final String value,
final String type) throws Exception {
String fullName = key;
if (nsPrefix != null) {
fullName = nsPrefix + ':' + key;
}
final XMLElement top = (XMLElement) stack.peek();
if (top.hasAttribute(fullName)) {
throw new XMLParseException(top.getSystemID(), top.getLineNr(), "Duplicate attribute: " + key);
}
if (nsPrefix != null) {
top.setAttribute(fullName, nsURI, value);
}
else {
top.setAttribute(fullName, 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 XML data source.
* @param lineNr
* the line in the source where the element starts.
*/
public void addPCData(final Reader reader, final String systemID, final int lineNr) {
int bufSize = 2048;
int sizeRead = 0;
final StringBuilder str = new StringBuilder(bufSize);
final char[] buf = new char[bufSize];
for (;;) {
if (sizeRead >= bufSize) {
bufSize *= 2;
str.ensureCapacity(bufSize);
}
int size;
try {
size = reader.read(buf);
}
catch (final IOException e) {
break;
}
if (size < 0) {
break;
}
str.append(buf, 0, size);
sizeRead += size;
}
final XMLElement elt = prototype.createElement(null, systemID, lineNr);
elt.setContent(str.toString());
if (!stack.empty()) {
final XMLElement top = (XMLElement) stack.peek();
top.addChild(elt);
}
}
/**
* 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. If no namespace has
* been specified, this parameter is null.
* @param nsURI
* the URI associated with the namespace. If no namespace has
* been specified, or no URI is associated with nsPrefix, this
* parameter is null.
*/
public void elementAttributesProcessed(final String name, final String nsPrefix, final String nsURI) {
}
/**
* 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. If no namespace has
* been specified, this parameter is null.
* @param nsURI
* the URI associated with the namespace. If no namespace has
* been specified, or no URI is associated with nsPrefix, this
* parameter is null.
*/
public void endElement(final String name, final String nsPrefix, final String nsURI) {
final XMLElement elt = (XMLElement) stack.pop();
if (elt.getChildrenCount() == 1) {
final XMLElement child = elt.getChildAtIndex(0);
if (child.getName() == null) {
elt.setContent(child.getContent());
elt.removeChildAtIndex(0);
}
}
}
/**
* Cleans up the object when it's destroyed.
*/
@Override
protected void finalize() throws Throwable {
prototype = null;
root = null;
stack.clear();
stack = null;
super.finalize();
}
/**
* Returns the result of the building process. This method is called just
* before the <I>parse</I> method of IXMLParser returns.
*
* @see org.freeplane.n3.nanoxml.IXMLParser#parse
* @return the result of the building process.
*/
public Object getResult() {
return root;
}
/**
* 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(final String target, final Reader reader) {
}
/**
* This method is called before the parser starts processing its input.
*
* @param systemID
* the system ID of the XML data source.
* @param lineNr
* the line on which the parsing starts.
*/
public void startBuilding(final String systemID, final int lineNr) {
stack = new Stack<XMLElement>();
root = null;
}
/**
* 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. If no namespace has
* been specified, this parameter is null.
* @param nsURI
* the URI associated with the namespace. If no namespace has
* been specified, or no URI is associated with nsPrefix, this
* parameter is null.
* @param systemID
* the system ID of the XML data source.
* @param lineNr
* the line in the source where the element starts.
*/
public void startElement(final String name, final String nsPrefix, final String nsURI, final String systemID,
final int lineNr) {
String fullName = name;
if (nsPrefix != null) {
fullName = nsPrefix + ':' + name;
}
final XMLElement elt = new XMLElement(fullName, nsURI, systemID, lineNr);
if (stack.empty()) {
root = elt;
}
else {
final XMLElement top = (XMLElement) stack.peek();
top.addChild(elt);
}
stack.push(elt);
}
}