DOMInit.java :  » J2EE » Pustefix » de » schlund » pfixcore » beans » metadata » Java Open Source

/*
 * This file is part of PFIXCORE.
 *
 * PFIXCORE is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * PFIXCORE 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 PFIXCORE; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

package de.schlund.pfixcore.beans.metadata;

import java.io.FileNotFoundException;
import java.net.URL;
import java.util.Iterator;

import javax.xml.XMLConstants;
import javax.xml.namespace.NamespaceContext;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.apache.log4j.Logger;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;

/**
 * @author mleidig@schlund.de
 */
public class DOMInit {
    
    protected final static Logger LOG=Logger.getLogger(DOMInit.class);
    
    public final static String XMLNS_BEANMETADATA="http://pustefix.sourceforge.net/beanmetadata";
    
    private Beans beans;
    
    public DOMInit() {
        beans=new Beans();
    }
    
    public DOMInit(Beans beans) {
        this.beans=beans;
    }
    
    public Beans getBeans() {
        return beans;
    }
    
    public void update(Document doc) throws DOMInitException {   
        NodeList beanNodeList=doc.getElementsByTagName("bean");
        for(int i=0;i<beanNodeList.getLength();i++) {
            Element beanElem=(Element)beanNodeList.item(i);
            String val=getAttribute("class",beanElem);
            if(val==null) throw new DOMInitException("Missing attribute: /bean-metadata/bean["+i+"]/@class");
            Bean bean=new Bean(val);
            if(beans.getBean(val)!=null) LOG.warn("Override metadata for bean '"+val+"'.");
            beans.setBean(bean);
            val=getAttribute("exclude-by-default",beanElem);
            if(val!=null && Boolean.parseBoolean(val)) bean.excludeByDefault();
            NodeList propNodeList=beanElem.getElementsByTagName("property");
            for(int j=0;j<propNodeList.getLength();j++) {
                Element propElem=(Element)propNodeList.item(j);
                val=getAttribute("name",propElem);
                if(val==null) throw new DOMInitException("Missing attribute: /bean-metadata/bean["+i+"]/property["+j+"]/@name");
                Property prop=new Property(val);
                bean.setProperty(prop);
                val=getAttribute("alias",propElem);
                if(val!=null) prop.setAlias(val);
                val=getAttribute("exclude",propElem);
                if(val!=null && Boolean.parseBoolean(val)) prop.exclude();
                val=getAttribute("include",propElem);
                if(val!=null && Boolean.parseBoolean(val)) prop.include();
            }
        }
    }
    
    private String getAttribute(String name,Element element) {
        String val=element.getAttribute(name);
        if(val!=null) {
            val=val.trim();
            if(val.equals("")) val=null;
        }
        return val;
    }
    
    public void update(URL metadataUrl) throws DOMInitException {
        if(LOG.isDebugEnabled()) LOG.debug("Update metadata from "+metadataUrl);
        DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();
        dbf.setValidating(false);
        dbf.setNamespaceAware(true);
        try {
            DocumentBuilder db=dbf.newDocumentBuilder();
            db.setErrorHandler(new MyErrorHandler());
            Document doc=db.parse(metadataUrl.openStream());
            update(doc);
        } catch(FileNotFoundException x) {
            if(LOG.isDebugEnabled()) LOG.debug("No metadata file found: "+metadataUrl.toString());
        } catch(Exception x) {
            throw new DOMInitException("Can't read metadata from '"+metadataUrl+"'.",x);
        }
    }
    
    
    class MyNamespaceContext implements NamespaceContext {
    
        public Iterator<String> getPrefixes(String namespaceURI) {
            return null;
        }
        
        public String getNamespaceURI(String prefix) {
            if(prefix.equals("bmd")) return XMLNS_BEANMETADATA;
            return XMLConstants.NULL_NS_URI;
        }
        
        public String getPrefix(String namespace) {
            if(namespace.equals(XMLNS_BEANMETADATA)) return "bmd";
            return null;
        }
       
    }  


    static class MyErrorHandler implements ErrorHandler {
     
        public void error(SAXParseException exception) throws SAXException {
            LOG.error(exception.getMessage());
            throw exception;
        }
        
        public void fatalError(SAXParseException exception) throws SAXException {
            LOG.error(exception.getMessage());
            throw exception;
        }
        
        public void warning(SAXParseException exception) throws SAXException {
            LOG.warn(exception.getMessage());
        }
        
    }
    
}