/**
* The contents of this file are subject to the license and copyright
* detailed in the LICENSE and NOTICE files at the root of the source
* tree and available online at
*
* http://www.dspace.org/license/
*/
package org.dspace.app.sfx;
import java.io.File;
import java.io.IOException;
import java.net.URLEncoder;
import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
import org.w3c.dom.Document;
import org.dspace.content.DCPersonName;
import org.dspace.content.Metadatum;
import org.dspace.content.Item;
import org.dspace.core.Constants;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
/**
* XML configuration file reader for DSpace metadata fields (DC) mapping
* to OpenURL parameters.
* <p>
* This class reads the [dspace]/config/sfx.xml configuration file, which
* contains pairs of DSpace item metadata values and OpenURL parameter names.
* Then it takes an item and constructs an OpenURL for it with values of
* parameters filled in from the paired metadata fields.
* </p>
*
* @author Stuart Lewis
* @author Graham Triggs
* @version $Revision$
*/
public class SFXFileReader {
/** The SFX configuration file */
private static Document doc;
/** log4j logger */
private static final Logger log = Logger.getLogger(SFXFileReader.class);
/**
* Loads the SFX configuration file
*
* @param fileName The name of the SFX configuration file
* @param item The item to process, from which metadata values will be taken
*
* @return the SFX string
* @throws IOException
*/
public static String loadSFXFile(String fileName, Item item) throws IOException
{
// Parse XML file -> XML document will be built
if (doc == null)
{
doc = parseFile(fileName);
}
// Return final sfx Query String
return doNodes(doc, item);
}
/** Parses XML file and returns XML document.
* @param fileName XML file to parse
* @return XML document or <B>null</B> if error occured. The error is caught and logged.
*/
public static Document parseFile(String fileName) {
log.info("Parsing XML file... " + fileName);
DocumentBuilder docBuilder;
Document doc = null;
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
docBuilderFactory.setIgnoringElementContentWhitespace(true);
try {
docBuilder = docBuilderFactory.newDocumentBuilder();
}
catch (ParserConfigurationException e) {
log.error("Wrong parser configuration: " + e.getMessage());
return null;
}
File sourceFile = new File(fileName);
try {
doc = docBuilder.parse(sourceFile);
}
catch (SAXException e) {
log.error("Wrong XML file structure: " + e.getMessage());
return null;
}
catch (IOException e) {
log.error("Could not read source file: " + e.getMessage());
}
log.info("XML file parsed");
return doc;
}
/**
* Process the item, mapping each of its metadata fields defined in the
* configuration file to an OpenURL parameter
*
* @param node DOM node of the mapping pair in the XML file (field element)
* @param item The item to process, from which metadata values will be taken
* @return processed fields.
* @throws IOException
*/
public static String doNodes(Node node, Item item) throws IOException
{
if (node == null)
{
log.error (" Empty Node ");
return null;
}
Node e = getElement(node);
NodeList nl = e.getChildNodes();
int len = nl.getLength();
String sfxfield = "";
int i = 0;
while ((i < len) && StringUtils.isEmpty(sfxfield))
{
Node nd = nl.item(i);
if ((nd == null) || isEmptyTextNode(nd))
{
i++;
continue;
}
String tagName = nd.getNodeName();
if (tagName.equals("query-pairs"))
{
sfxfield = processFields(nd, item);
}
i++;
}
log.info("Process fields : " + sfxfield);
return sfxfield;
}
/**
* Process the field nodes, mapping each metadata field defined in the
* configuration file to an OpenURL parameter
*
* @param e DOM node of the mapping pair in the XML file (field element)
* @param item The item to process, from which metadata values will be taken
* @return assembled OpenURL query.
* @throws IOException
*/
private static String processFields(Node e, Item item) throws IOException
{
NodeList cl = e.getChildNodes();
int lench = cl.getLength();
String myquery = "";
for (int j = 0; j < lench; j++)
{
Node nch = cl.item(j);
String querystring = "";
String schema = "";
String qualifier = "";
String element = "";
if (nch.getNodeName().equals("field"))
{
NodeList pl = nch.getChildNodes();
int plen = pl.getLength();
int finish = 0;
for (int k = 0; k < plen; k++)
{
Node vn= pl.item(k);
String vName = vn.getNodeName();
if (vName.equals("querystring"))
{
querystring = getValue(vn);
finish ++;
}
else if (vName.equals("dc-schema"))
{
schema = getValue(vn);
finish ++;
}
else if (vName.equals("dc-element"))
{
element = getValue(vn);
finish ++;
}
else if (vName.equals("dc-qualifier"))
{
qualifier = getValue(vn);
finish ++;
if (StringUtils.isEmpty(qualifier))
{
qualifier = null;
}
}
if (finish == 4)
{
Metadatum[] dcvalue = item.getMetadata(schema, element, qualifier, Item.ANY);
if (dcvalue.length > 0)
{
// Issued Date
if (element.equals("date") && qualifier.equals("issued"))
{
String fullDate = dcvalue[0].value;
// Remove the time if there is one - day is greatest granularity for SFX
if (fullDate.length() > 10)
{
fullDate = fullDate.substring(0, 10);
}
if (myquery.equals(""))
{ myquery = querystring + URLEncoder.encode(fullDate, Constants.DEFAULT_ENCODING); }
else
{ myquery = myquery + "&" + querystring + URLEncoder.encode(fullDate, Constants.DEFAULT_ENCODING); }
}
else
{
// Contributor Author
if (element.equals("contributor") && qualifier.equals("author"))
{
DCPersonName dpn = new DCPersonName(dcvalue[0].value);
String dpnName = dcvalue[0].value;
if (querystring.endsWith("aulast=")) { dpnName = dpn.getLastName(); }
else { if (querystring.endsWith("aufirst=")) { dpnName = dpn.getFirstNames(); }}
if (myquery.equals(""))
{ myquery = querystring + URLEncoder.encode(dpnName, Constants.DEFAULT_ENCODING); }
else
{ myquery = myquery + "&" + querystring + URLEncoder.encode(dpnName, Constants.DEFAULT_ENCODING); }
}
else
{
if (myquery.equals(""))
{ myquery = querystring + URLEncoder.encode(dcvalue[0].value, Constants.DEFAULT_ENCODING);}
else
{ myquery = myquery + "&" + querystring + URLEncoder.encode(dcvalue[0].value, Constants.DEFAULT_ENCODING);}
}
}
} // if dc.length > 0
finish = 0;
querystring = "";
schema = "";
element = "";
qualifier = "";
} // if finish == 4
} //for k
} // if field
} // for j
return myquery;
}
/** Returns element node
* @param node element (it is XML tag)
* @return Element node otherwise null
*/
public static Node getElement(Node node)
{
NodeList child = node.getChildNodes();
int length = child.getLength();
for (int i = 0; i < length; i++)
{
Node kid = child.item(i);
if (kid.getNodeType() == Node.ELEMENT_NODE)
{
return kid;
}
}
return null;
}
/** Is Empty text Node **/
public static boolean isEmptyTextNode(Node nd)
{
boolean isEmpty = false;
if (nd.getNodeType() == Node.TEXT_NODE)
{
String text = nd.getNodeValue().trim();
if (text.length() == 0)
{
isEmpty = true;
}
}
return isEmpty;
}
/**
* Returns the value of the node's attribute named <name>
**/
public static String getAttribute(Node e, String name)
{
NamedNodeMap attrs = e.getAttributes();
int len = attrs.getLength();
if (len > 0)
{
for (int i = 0; i < len; i++)
{
Node attr = attrs.item(i);
if (name.equals(attr.getNodeName()))
{
return attr.getNodeValue().trim();
}
}
}
//no such attribute
return null;
}
/**
* Returns the value found in the Text node (if any) in the
* node list that's passed in.
*/
public static String getValue(Node node)
{
NodeList child = node.getChildNodes();
for (int i = 0; i < child.getLength(); i++)
{
Node kid = child.item(i);
short type = kid.getNodeType();
if (type == Node.TEXT_NODE)
{
return kid.getNodeValue().trim();
}
}
// Didn't find a text node
return null;
}
}