axiom/modules/axiom-api/src/main/java/org/apache/axiom/om/impl/builder/SAXOMBuilder.java

/*
 * Copyright 2004,2005 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.axiom.om.impl.builder;

import org.apache.axiom.om.OMAbstractFactory;
import org.apache.axiom.om.OMContainer;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMException;
import org.apache.axiom.om.OMFactory;
import org.apache.axiom.om.OMNode;
import org.apache.axiom.om.impl.OMNodeEx;
import org.xml.sax.Attributes;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import java.util.ArrayList;
import java.util.List;

public class SAXOMBuilder extends DefaultHandler {
    OMElement root = null;

    OMNode lastNode = null;

    OMElement nextElem = null;

    OMFactory factory = OMAbstractFactory.getOMFactory();

    List prefixMappings = new ArrayList();

    public void setDocumentLocator(Locator arg0) {
    }

    public void startDocument() throws SAXException {

    }

    public void endDocument() throws SAXException {
    }

    protected OMElement createNextElement(String localName) throws OMException {
        OMElement e;
        if (lastNode == null) {
            root = e = factory.createOMElement(localName, null, null, null);
        } else if (lastNode.isComplete()) {
            e = factory.createOMElement(localName, null, lastNode.getParent(),
                    null);
            ((OMNodeEx)lastNode).setNextOMSibling(e);
            ((OMNodeEx)e).setPreviousOMSibling(lastNode);
        } else {
            OMElement parent = (OMElement) lastNode;
            e = factory.createOMElement(localName, null, (OMElement) lastNode,
                    null);
            parent.setFirstChild(e);
        }
        return e;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.xml.sax.ContentHandler#startPrefixMapping(java.lang.String,
     *      java.lang.String)
     */
    public void startPrefixMapping(String prefix, String uri)
            throws SAXException {
        if (nextElem == null)
            nextElem = createNextElement(null);
        nextElem.declareNamespace(uri, prefix);
    }

    public void endPrefixMapping(String arg0) throws SAXException {
    }

    /*
     * (non-Javadoc)
     *
     * @see org.xml.sax.ContentHandler#startElement(java.lang.String,
     *      java.lang.String, java.lang.String, org.xml.sax.Attributes)
     */
    public void startElement(String namespaceURI, String localName,
                             String qName, Attributes atts) throws SAXException {
        if (localName == null || localName.trim().equals(""))
            localName = qName.substring(qName.indexOf(':') + 1);
        if (nextElem == null)
            nextElem = createNextElement(localName);
        else
            nextElem.setLocalName(localName);
        nextElem
                .setNamespace(nextElem.findNamespace(namespaceURI, null));
        int j = atts.getLength();
        for (int i = 0; i < j; i++)
            nextElem.addAttribute(atts.getLocalName(i), atts.getValue(i),
                    nextElem.findNamespace(atts.getURI(i), null));
        lastNode = nextElem;
        nextElem = null;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.xml.sax.ContentHandler#endElement(java.lang.String,
     *      java.lang.String, java.lang.String)
     */
    public void endElement(String arg0, String arg1, String arg2)
            throws SAXException {
        if (lastNode.isComplete()) {
            OMContainer parent = lastNode.getParent();
            ((OMNodeEx)parent).setComplete(true);
            lastNode = (OMNode) parent;
        } else {
            OMElement e = (OMElement) lastNode;
            ((OMNodeEx)e).setComplete(true);
        }
    }

    /*
     * (non-Javadoc)
     *
     * @see org.xml.sax.ContentHandler#characters(char[], int, int)
     */
    public void characters(char[] ch, int start, int length)
            throws SAXException {
        if (lastNode == null) {
            throw new SAXException("");
        }
        OMNode node;
        if (lastNode.isComplete()) {
            node =
                    factory.createOMText(lastNode.getParent(),
                            new String(ch,
                                    start, length));
            ((OMNodeEx)lastNode).setNextOMSibling(node);
            ((OMNodeEx)node).setPreviousOMSibling(lastNode);
        } else {
            OMElement e = (OMElement) lastNode;
            node = factory.createOMText(e, new String(ch, start, length));
            e.setFirstChild(node);
        }
        lastNode = node;
    }

    public void ignorableWhitespace(char[] arg0, int arg1, int arg2)
            throws SAXException {
    }

    public void processingInstruction(String arg0, String arg1)
            throws SAXException {
    }

    public void skippedEntity(String arg0) throws SAXException {
    }

    /**
     * @return Returns the root.
     */
    public OMElement getRootElement() {
        return root;
    }
}