org.batoo.jpa.parser.impl.orm.OrmContentHandler.java Source code

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Here is the source code for org.batoo.jpa.parser.impl.orm.OrmContentHandler.java

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/*
 * Copyright (c) 2012-2013, Batu Alp Ceylan
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.batoo.jpa.parser.impl.orm;

import java.util.Map;
import java.util.Stack;

import org.apache.commons.lang.StringUtils;
import org.batoo.common.log.BLogger;
import org.batoo.common.log.BLoggerFactory;
import org.batoo.jpa.parser.MappingException;
import org.batoo.jpa.parser.metadata.Metadata;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;

import com.google.common.collect.Maps;

/**
 * The content handler for ORM XML Files.
 * 
 * @author hceylan
 * @since 2.0.0
 */
public class OrmContentHandler implements ContentHandler {

    private static final BLogger LOG = BLoggerFactory.getLogger(OrmContentHandler.class);

    private final String fileName;
    private Locator locator;
    private final Stack<Element> elementStack = new Stack<Element>();
    private EntityMappings entityMappings;

    /**
     * @param fileName
     *            the name of the ORM XML file
     * 
     * @since 2.0.0
     */
    public OrmContentHandler(String fileName) {
        super();

        this.fileName = fileName;
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        String cdata = new String(ch, start, length);
        if (cdata.startsWith("![CDATA[")) {
            cdata = cdata.substring(8, cdata.length() - 2);
        }

        if (StringUtils.isNotBlank(cdata)) {
            OrmContentHandler.LOG.trace("Element body {0}", cdata);

            this.elementStack.peek().cdata(cdata);
        }
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void endDocument() throws SAXException {
        OrmContentHandler.LOG.debug("ORM Parsing is over for {0}", this.fileName);
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void endElement(String uri, String localName, String qName) throws SAXException {
        OrmContentHandler.LOG.trace("End of element url: {0}, localName: {1}, qName: {2}", uri, localName, qName);

        final Element element = this.elementStack.pop();

        element.end();
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void endPrefixMapping(String prefix) throws SAXException {
        OrmContentHandler.LOG.trace("End of prefix mapping {0}", prefix);
    }

    /**
     * Returns the metadata.
     * 
     * @return the metadata
     * 
     * @since 2.0.0
     */
    public Metadata getMetadata() {
        return this.entityMappings;
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {
        OrmContentHandler.LOG.trace("Ignorable whitespace {0}", new String(ch, start, length));
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void processingInstruction(String target, String data) throws SAXException {
        OrmContentHandler.LOG.trace("Processing instructions {0}, {1}", target, data);
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void setDocumentLocator(Locator locator) {
        this.locator = locator;
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void skippedEntity(String name) throws SAXException {
        OrmContentHandler.LOG.warn("Skipped entity {0}", name);
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void startDocument() throws SAXException {
        OrmContentHandler.LOG.debug("ORM Parsing started for {0}", this.fileName);
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
        final Map<String, String> attributes = Maps.newHashMap();

        for (int i = 0; i < atts.getLength(); i++) {
            final String name = atts.getLocalName(i);
            final String value = atts.getValue(i);

            attributes.put(name, value);
        }

        OrmContentHandler.LOG.trace("Start of element url: {0}, localName: {1}, qName: {2}, attributes: {3}", uri,
                localName, qName, attributes);

        // if stack is empty we are at the root of the document
        if (this.elementStack.size() == 0) {
            if (!ElementConstants.ELEMENT_ENTITY_MAPPINGS.equals(localName)) {
                throw new MappingException(
                        "Unexpected element '" + ElementConstants.ELEMENT_ENTITY_MAPPINGS + "' encountered.",
                        new XmlLocator(this.fileName, localName, this.locator));
            }

            this.entityMappings = new EntityMappings(attributes);
            this.elementStack.push(this.entityMappings);
        }
        // check if the element is expected
        else {
            this.elementStack.peek().expected(localName, this.locator);

            // push the new Element to the stack
            final XmlLocator xmlLocator = new XmlLocator(this.fileName, localName, this.locator);
            this.elementStack.push(Element.forElement(this.elementStack.peek(), attributes, xmlLocator));
        }
    }

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    public void startPrefixMapping(String prefix, String uri) throws SAXException {
        OrmContentHandler.LOG.trace("Start of prefix mapping url: {0}, prefix: {1}", uri, prefix);
    }
}