--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/common/src/main/java/digilib/meta/XMLMetaLoader.java	Tue Apr 26 20:24:31 2011 +0200
@@ -0,0 +1,287 @@
+/* XMLMetaLoader -- Load an XML format metadata into a Hashtable
+
+  Digital Image Library servlet components
+
+  Copyright (C) 2003 Robert Casties (robcast@mail.berlios.de)
+
+  This program is free software; you can redistribute  it and/or modify it
+  under  the terms of  the GNU General  Public License as published by the
+  Free Software Foundation;  either version 2 of the  License, or (at your
+  option) any later version.
+   
+  Please read license.txt for the full details. A copy of the GPL
+  may be found at http://www.gnu.org/copyleft/lgpl.html
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+*/
+
+package digilib.meta;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.LinkedList;
+import java.util.Map;
+
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.parsers.SAXParser;
+import javax.xml.parsers.SAXParserFactory;
+
+import org.apache.log4j.Logger;
+import org.xml.sax.Attributes;
+import org.xml.sax.SAXException;
+import org.xml.sax.helpers.DefaultHandler;
+
+public class XMLMetaLoader {
+
+	private Logger logger = Logger.getLogger(this.getClass());
+	private String metaTag = "meta";
+	private String fileTag = "file";
+	private String fileNameTag = "name";
+	private String filePathTag = "path";
+	private String imgTag = "img";
+	private String collectTag = "context";
+
+	public XMLMetaLoader() {
+	}
+
+	/**
+	 *  inner class XMLMetaParser to be called by the parser
+	 */
+	private class XMLMetaParser extends DefaultHandler {
+
+		private LinkedList<String> tags;
+		private Map<String, MetadataMap> files;
+		private MetadataMap meta;
+		private StringBuffer content;
+		private boolean collecting;
+		private StringBuffer collectedContent;
+		private String fileName;
+		private String filePath;
+
+		/**
+		 * extracts the elements name from either localName ln or qName qn.
+		 * 
+		 * @param ln localName
+		 * @param qn qName
+		 * @return element name
+		 */
+		private String getName(String ln, String qn) {
+			if (ln != null) {
+				if (ln.length() > 0) {
+					return ln;
+				}
+			}
+			// else it's qName (or nothing)
+			return qn;
+		}
+
+		/**
+		 * returns all attributes as a String
+		 * 
+		 * @param attrs
+		 * @return 
+		 */
+		private String getAttrString(Attributes attrs) {
+			StringBuffer s = new StringBuffer();
+			for (int i = 0; i < attrs.getLength(); i++) {
+				String key = getName(attrs.getLocalName(i), attrs.getQName(i));
+				s.append(" "+key+"=\""+attrs.getValue(i)+"\"");
+			}
+			return s.toString();
+		}
+
+			
+		// Parser calls this once at the beginning of a document
+		public void startDocument() throws SAXException {
+			tags = new LinkedList<String>();
+			files = new HashMap<String, MetadataMap>();
+			collecting = false;
+			collectedContent = null;
+		}
+
+		// Parser calls this for each element in a document
+		public void startElement(
+			String namespaceURI,
+			String localName,
+			String qName,
+			Attributes atts)
+			throws SAXException {
+
+			String name = getName(localName, qName);
+			// open a new tag
+			tags.addLast(name);
+			// start new content (no nesting of tags and content)
+			content = new StringBuffer();
+
+			if (name.equals(metaTag)) {
+				// new meta tag
+				meta = new MetadataMap();
+				collectedContent = new StringBuffer();
+			} else if (name.equals(fileTag)) {
+				// new file tag
+				fileName = null;
+				filePath = null;
+				meta = new MetadataMap();
+				collectedContent = new StringBuffer();
+			} else if (name.equals(collectTag)) {
+				// start collecting
+				collecting = true;
+				if (collectedContent == null) {
+					collectedContent = new StringBuffer();
+				}
+			}
+			
+			// record mode
+			if (collecting) {
+				collectedContent.append("<"+name);
+				collectedContent.append(getAttrString(atts));
+				collectedContent.append(">");
+			}
+		}
+
+		// parser calls this for all tag content (possibly more than once)
+		public void characters(char[] ch, int start, int length)
+			throws SAXException {
+			// append data to current string buffer
+			if (content == null) {
+				content = new StringBuffer();
+			}
+			content.append(ch, start, length);
+		}
+
+		// parser calls this at the end of each element
+		public void endElement(
+			String namespaceURI,
+			String localName,
+			String qName)
+			throws SAXException {
+
+			String name = getName(localName, qName);
+			// exit the tag
+			tags.removeLast();
+			String lastTag = (tags.isEmpty()) ? "" : tags.getLast();
+
+			// was it a file/name tag?
+			if (name.equals(fileNameTag) && lastTag.equals(fileTag)) {
+				// save name as filename
+				if ((content != null) && (content.length() > 0)) {
+					fileName = content.toString().trim();
+				}
+				content = null;
+				return;
+			}
+
+			// was it a file/path tag?
+			if (name.equals(filePathTag) && lastTag.equals(fileTag)) {
+				// save path as filepath 
+				if ((content != null) && (content.length() > 0)) {
+					filePath = content.toString().trim();
+				}
+				content = null;
+				return;
+			}
+
+			// was it a file tag?
+			if (name.equals(fileTag)) {
+				// is there meta to save?
+				if ((meta != null) && (meta.size() > 0)) {
+					// file name is (optional file/path) / file/name
+					String fn = null;
+
+					if (fileName != null) {
+						if (filePath != null) {
+							fn = filePath + "/" + fileName;
+						} else {
+							fn = fileName;
+						}
+					} else {
+						// no file name, no file
+						content = null;
+						return;
+					}
+					// save meta in file list 
+					files.put(fn, meta);
+				}
+				content = null;
+				return;
+			}
+
+			// was it a meta tag outside a file tag?
+			if (name.equals(metaTag) && !tags.contains(fileTag)) {
+				// save meta as dir meta
+				if ((meta != null) && (meta.size() > 0)) {
+					files.put("", meta);
+				}
+				content = null;
+				return;
+			}
+
+			// is this inside an digilib info (=img) tag?
+			if (lastTag.equals(imgTag)) {
+				// then add whatever this is
+				if ((content != null) && (content.length() > 0)) {
+					meta.put(name, content.toString().trim());
+				}
+				content = null;
+				return;
+			}
+
+			// is this the end of collectTag?
+			if (name.equals(collectTag)) {
+				collecting = false;
+				collectedContent.append("</"+collectTag+">\n");
+				// store collected stuff
+				meta.put(collectTag, collectedContent.toString());
+				//logger.debug("collected: '"+collectedContent+"'");
+				content = null;
+				return;
+			}
+
+			// write collected content
+			if (collecting) {
+				String s = "";
+				if ((content != null) && (content.length() > 0)) {
+					s = content.toString().trim();
+				}
+				//logger.debug("collect:"+name+" = "+s);
+				collectedContent.append(s);
+				collectedContent.append("</"+name+">\n");
+				content = null;
+				return;
+			}
+		}
+
+	}
+
+	/**
+	 *  load and parse a file (as URL)
+	 *    returns HashMap with list data
+	 */
+	public Map<String, MetadataMap> loadURL(String path) throws SAXException, IOException {
+		logger.debug("loading meta: "+path);
+		// Create a JAXP SAXParserFactory and configure it
+		SAXParserFactory spf = SAXParserFactory.newInstance();
+		spf.setNamespaceAware(true);
+
+		SAXParser parser = null;
+		try {
+			// Create a JAXP SAXParser
+			parser = spf.newSAXParser();
+
+		} catch (ParserConfigurationException e) {
+			throw new SAXException(e);
+		}
+
+		// create a list parser (keeps the data!)
+		XMLMetaParser listParser = new XMLMetaParser();
+
+		// Tell the SAXParser to parse the XML document
+		parser.parse(path, listParser);
+
+		return listParser.files;
+	}
+
+}