/***************************************************************************************************** * $Id: DefaultApplyXSL.java,v 1.4 2000/08/23 14:40:06 dleslie Exp $ * * Copyright (c) 1998-1999 Lotus Corporation, Inc. All Rights Reserved. * This software is provided without a warranty of any kind. * * $State: Exp $ *****************************************************************************************************/ import org.w3c.dom.*; import org.xml.sax.*; import java.io.*; import java.net.*; import java.util.*; import javax.servlet.*; import javax.servlet.http.*; import org.apache.xerces.parsers.DOMParser; // import org.apache.xerces.framework.Catalog; // import com.ibm.xml.internal.XCatalog; import org.apache.xalan.xslt.XSLTInputSource; /***************************************************************************************************** * DefaultApplyXSL extends the ApplyXSL abstract class. It's primary function is to provide a * baseline servlet to let you apply XSL stylesheets to XML data at the server. Why do you * want to apply XSL stylesheets to XML data at the server? Because you can maximize the sharability * of your data without regard to the XML/XSL processing capabilities of your clients. * *

Attempts will be made to create an XML XSLTInputSource DOM from the following sources:

*
    *
  1. A relative URL specified in the HTTP request's path information. This capability is intended * for use by servlet engines that map some or all XML data to be processed at the server.
    2. *
  2. A URL specified in the HTTP request's URL= parameter. This capability * is intended for clients wishing to selectively process XML data at the server. For * security reasons, this URL will be forced to the local IP host.
    3. *
  3. The HTTP request's XML input stream. This capability is intended for use by chained servlets.
    4. *
* *

Attempts will be made to create an XSL XSLTInputSource from the following sources:

*
    *
  1. A URL specified in the HTTP request's xslURL= parameter. This capability * is intended for clients wishing to selectively override the server algorithm for applying XSL * stylesheets. For security reasons, this URL will be forced to the local IP host.
    2. *
  2. XML association. XML XSLTInputSources may contain references to one or more stylesheets using * this W3C proposed recommendation. * If the XML XSLTInputSource does contain such references, a best match will be chosen based on the browser * type making the request and the default association. This capability enables relationships to be * defined between client capabilities and stylesheets capable of acting on these capabilities.
    3. *
  3. A configured default stylesheet URL
    4. *
* *
* *

This servlet requires the following software:

* * *
* *

If you are running WebSphere Application Server v2.03 or later, this servlet is already * installed and default configured. Otherwise, install this servlet by:

*
    *
  1. Ensure that your servlet engine meets the system requirements.
    2. *
  2. Install the xml4j.jar and lotusxsl.jar files in your servlet engine's class path. Unfortunately, * the servlet specification does not yet define a standard way to install servlets. Please refer to * your servlet engine's operational instructions; for IBM WebSphere Application Server, the instructions * are here.
    3. *
  3. Copy the lotusxsl/examples/servlet/media.properties file * to a servlet-accessible location in your directory tree. This file provides configuration * information to this servlet.
    4. *
  4. Copy the lotusxsl/examples/servlet/*.xsl files to a servlet-accessible location in your * directory tree. These files provide default XSL stylesheets to be used when no others are * available. Default.xsl provides a Microsoft IE5-like default display using JavaScript to expand * and contract nodes; default2.xsl provides a similar display without the use of JavaScript.
    5. *
  5. Configure this servlet to your servlet engine. Once again, the servlet specification defines * no standard servlet configuration procedure, so you must consult the operational instructions for * your servlet engine. * * * * * * * * * * * * * * * * * * * * * * * * *
    * Default Apply XSL Servlet Base Configuration
    Parm NameParm ValueRequired?
    Servlet NameDefaultApplyXSLYes
    DescriptionApply XSL to XMLNo
    Servlet Classcom.lotus.xsl.server.DefaultApplyXSLYes
    *
    * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
    * Default Apply XSL Servlet Initialization Properties
    DescriptionParm NameParm ValueRequired?Default Value
    Location of user-Agent/media mapping rules filemediaURLa full URL, or path relative to the System's server.root /servlets directoryNoNone
    XSL stylesheet URLxslURLhttp://localhost/localpath/yourDefault.xslNoNone
    Run in debug mode?debugtrue or falseNofalse
    Generate warning messages from XSL processornoConflictWarningstrue or falseNofalse
    Catalog for public identifierscataloga full URLNonone
    *
    6. *
  6. If you wish to configure your servlet engine to automatically process some or all XML data * at the server, you should follow your servlet engine's operational instructions on how to * route these files to the default apply XSL servlet. Usually, this entails defining a servlet * filter(s) or alias(es).
    7. *
  7. Restart your servlet engine.
    8. *
  8. Access an XML XSLTInputSource using one of the techniques outlined in the * examples
    9. *
* *
* *

The following examples serve to illustrate the use of this servlet:

*
*
http://localhost/servlet/DefaultApplyXSL?URL=/data.xml&xslURL=/style.xsl
*
...will apply the style.xsl stylesheet to the data.xml data. Both files will be * served from the Web server's HTTP XSLTInputSource root.
*
http://localhost/servlet/DefaultApplyXSL?URL=/data.xml&xslURL=/style.xsl&debug=true
*
...will ensure that XML and XSL processor messages will be returned in the event of problems * applying style.xsl to data.xml
*
http://localhost/servlet/DefaultApplyXSL/data.xml?xslURL=/style.xsl
*
...will apply the style.xsl stylesheet to the data.xml data, just like the first example. * This is an alternative way of specifying the XML XSLTInputSource by utilizing the HTTP request's path * information. *
http://localhost/servlet/DefaultApplyXSL/data.xml
*
...will examine data.xml for an associated * XSL stylesheet. If multiple XSLs are associated with the data, the stylesheet whose media * attribute maps to your browser type will be chosen. If no mapping is * successful, the primary associated stylesheet will be used. *
http://localhost/servlet/data.xml
*
...will provide the exact same function as the previous example, but this example assumes * that /servlet/data.xml has been mapped to be executed by this servlet. The servlet engine may be configured * to map all or some *.xml files to this servlet through the use of servlet aliases or filters. *
http://localhost/servlet/data.xml?catalog=http://www.xml.org/dtds/oag.xml
*
...will supplement any servlet-configured XCatalog * with a catalog of supply chain DTDs residing at the XML.ORG DTD repository. *
* *
* *

The following usage notes may prove...well...useful:

* * * @author Spencer Shepard (sshepard@us.ibm.com) * @author R. Adam King (rak@us.ibm.com) * @author Tom Rowe (trowe@us.ibm.com) * *****************************************************************************************************/ import org.apache.xalan.xslt.XSLTProcessor; public class DefaultApplyXSL extends ApplyXSL { /** * Mapping of HTTP request's user-Agent values to stylesheet media= values. *

This mapping is defined by a file pointed to by the operational parameter "mediaURL" which can * either contain a full URL or a path relative to the System's server.root /servlets directory.

* @see #setMediaProps * @see #getMedia * @serial */ protected OrderedProps ourMediaProps = null; /** * Initialize operational parameters from the configuration. * @param config Configuration * @exception ServletException Never thrown */ public void init(ServletConfig config) throws ServletException { super.init(config); setMediaProps(config.getInitParameter("mediaURL")); } /** * Overrides method in ApplyXSL in order to use DefaultApply Properties. * @param config Configuration */ protected void setDefaultParameters(ServletConfig config) { ourDefaultParameters = new DefaultApplyXSLProperties(config); } /** * Returns a connection which respects the Accept-Language header of the HTTP request. This * is useful when XSL files are internationalized for use with Web servers which respect this * header. *

For example, Apache 1.3.6 may be configured for multiviews. Under this configuration, * requests for http://myhost/index.html would return http://myhost/index.html.fr to French browsers * and http://myhost/index.html.en to English browsers.

* @param url Location to connect to * @param request Could contain an Accept-Language header * @return An Accept-Language-enabled URL connection * @see #getStylesheet */ protected URLConnection toAcceptLanguageConnection(URL url, HttpServletRequest request) throws Exception { URLConnection tempConnection = url.openConnection(); tempConnection.setRequestProperty("Accept-Language", request.getHeader("Accept-Language")); return tempConnection; } /** * Loads the media properties file specified by the given string. * @param mediaURLstring Location of the media properties file. Can be either a full URL or a path relative * to the System's server.root /servlets directory. If this parameter is null, * server.root/servlets/media.properties will be used. * @see ApplyXSL#CURRENTDIR */ protected void setMediaProps(String mediaURLstring) { if (mediaURLstring != null) { URL url = null; try { url = new URL(mediaURLstring); } catch (MalformedURLException mue1) { try { url = new URL("file", "", CURRENTDIR + mediaURLstring); } catch (MalformedURLException mue2) { writeLog("Unable to find the media properties file based on parameter 'mediaURL' = " + mediaURLstring, HttpServletResponse.SC_ACCEPTED, mue2); url = null; } } if (url != null) { try { ourMediaProps = new OrderedProps(url.openStream()); } catch (IOException ioe1) { writeLog("Exception occurred while opening media properties file: " + mediaURLstring + ". Media table may be invalid.", HttpServletResponse.SC_ACCEPTED, ioe1); } } } else { String defaultProp = CURRENTDIR + "media.properties"; try { ourMediaProps = new OrderedProps(new FileInputStream(defaultProp)); } catch (IOException ioe2) { writeLog("Default media properties file " + defaultProp + " not found.", HttpServletResponse.SC_ACCEPTED, ioe2); } } } /** * Returns a DOM from the specified input stream. * @param request Could contain the URL(s) for catalog(s) * @param ins Input stream to parse * @param listener To record detailed parsing messages for a possible return to requestor * @return The DOM * @exception IOException Thrown when input stream cannot be opened for parsing * @exception SAXException Thrown by parser if stream not XSLTInputSource compliant * @exception com.lotus.xsl.XSLProcessorException Thrown when stream cannot be parsed * @exception Exception Only the above Exceptions should be thrown */ public XSLTInputSource makeDocument(XSLTProcessor processor, HttpServletRequest request, InputStream ins, ErrorHandler listener) throws Exception { /* DOMParser parser = new DOMParser(); //parser.setNodeExpansion(NonValidatingDOMParser.DEFERRED); parser.setNodeExpansion(NonValidatingDOMParser.FULL); parser.setExpandEntityReferences(true); parser.setErrorHandler(listener); String catalogURL[] = ((DefaultApplyXSLProperties) ourDefaultParameters).getCatalog(request); if (catalogURL != null) { XCatalog catalog = new XCatalog(parser.getParserState()); parser.getEntityHandler().setEntityResolver(catalog); int i, len = catalogURL.length; for (i = 0; i < len; i++) { parser.loadCatalog(new InputSource(catalogURL[i])); } } parser.parse(new InputSource(ins)); return new XSLTInputSource(parser.getDocument()); */ XSLTInputSource source = new XSLTInputSource(ins); // Not sure what to do about the catalog business here. If this is needed, // we should have the liaison do it, if possible. return source; } /** * Returns a media name mapped from the specified request's user-Agent header. * This mapping enables relationships to be defined between client capabilities and stylesheets * capable of acting on these capabilities. *

Refer to the media.properties file for details.

* @param request Contains the user-Agent header * @return The media name that corresponds to the user-Agent, or "unknown" * @see #getStylesheet * @see #HEADER_NAME */ public String getMedia(HttpServletRequest request) { return ourMediaProps.getValue(request.getHeader(HEADER_NAME)); } /** * Returns the XSL stylesheet URL associated with the specified XML document. If multiple XSL * stylesheets are associated with the XML document, preference will be given to the stylesheet * which contains an attribute name/value pair that corresponds to the specified attributeName * and attributeValue. * @param xmlSource XML XSLTInputSource to be searched for associated XSL stylesheets * @param attributeName Attribute name to provide preferential matching * @param attributeValue Attribute value to provide preferential matching * @return The preferred XSL stylesheet URL, or null if no XSL stylesheet association is found * @see #getStylesheet */ public static String getXSLURLfromDoc(XSLTInputSource xmlSource, String attributeName, String attributeValue, XSLTProcessor processor) { String tempURL = null, returnURL = null; try { Node sourceTree = processor.getSourceTreeFromInput(xmlSource); //replaced xmlSource.getNode() for(Node child=sourceTree.getFirstChild(); null != child; child=child.getNextSibling()) { if(Node.PROCESSING_INSTRUCTION_NODE == child.getNodeType()) { ProcessingInstruction pi = (ProcessingInstruction)child; if(pi.getNodeName().equals("xml-stylesheet")) { PIA pia = new PIA(pi); if("text/xsl".equals(pia.getAttribute("type"))) { tempURL = pia.getAttribute("href"); String attribute = pia.getAttribute(attributeName); if ((attribute != null) && (attribute.indexOf(attributeValue) > -1)) return tempURL; if (!"yes".equals(pia.getAttribute("alternate"))) returnURL = tempURL; } } } } } catch(Exception saxExc) { } return returnURL; } /** * Returns an XSL XSLTInputSource. Attempts will be make to create the Stylesheet from the following * sources: *
    *
  1. A URL specified in the HTTP request's xslURL= parameter. This capability * is intended for clients wishing to selectively override the server algorithm for applying XSL * stylesheets. For security reasons, this URL will be forced to the local IP host.
    2. *
  2. XML association. XML documents may contain references to one or more stylesheets using * this W3C proposed recommendation. * If the XML document does contain such references, a best match will be chosen based on the browser * type making the request and the default association. This capability enables relationships to be * defined between client capabilities and stylesheets capable of acting on these capabilities.
    3. *
  3. A configured default stylesheet URL
    4. *
* @param request May contain or point to the XSL XSLTInputSource * @param xmlSource May point to the XSL XSLTInputSource * @param listener To record detailed parsing messages for possible return to requestor * @return XSL XSLTInputSource, or null if the request could not be parsed * @see #makeDocument * @see #getMedia * @see #STYLESHEET_ATTRIBUTE * @see #getXSLURLfromDoc * @see #toAcceptLanguageConnection * @exception ApplyXSLException Thrown if exception occurs while handling request */ protected XSLTInputSource getStylesheet(HttpServletRequest request, XSLTInputSource xmlSource, ApplyXSLListener listener, XSLTProcessor processor) throws ApplyXSLException { try { //stylesheet URL from request String xslURL = ((DefaultApplyXSLProperties) ourDefaultParameters).getXSLRequestURL(request); if (xslURL != null) listener.out.println("Parsing XSL Stylesheet Document from request parameter: " + xslURL); else { // find stylesheet from XML Document, Media tag preference if (xmlSource != null){ listener.out.println("calling getXSLURLfromDoc and getMedia " + getMedia(request) ); xslURL = getXSLURLfromDoc(xmlSource, STYLESHEET_ATTRIBUTE, getMedia(request), processor); } if (xslURL != null) listener.out.println("Parsing XSL Stylesheet Document from XML Document tag: " + xslURL); else // Configuration Default if ((xslURL = ourDefaultParameters.getXSLurl(null)) != null) listener.out.println("Parsing XSL Stylesheet Document from configuration: " + xslURL); } return new XSLTInputSource(xslURL); // replacement for following statement 05-19-00 // return new XSLTInputSource(toAcceptLanguageConnection(new URL(xslURL), // request).getURL().toString()); } catch (IOException ioe) { throw new ApplyXSLException(ioe, HttpServletResponse.SC_NOT_FOUND); } catch (Exception e) { throw new ApplyXSLException(e, HttpServletResponse.SC_INTERNAL_SERVER_ERROR); } } /** * Returns an XML XSLTInputSource DOM. Attempts will be make to create the DOM from the following * sources: *
    *
  1. A relative URL specified in the HTTP request's path information. This capability is intended * for use by servlet engines that map some or all XML data to be processed at the server.
    2. *
  2. A URL specified in the HTTP request's URL= parameter. This capability * is intended for clients wishing to selectively process XML data at the server. For * security reasons, this URL will be forced to the local IP host.
    3. *
  3. The HTTP request's XML input stream. This capability is intended for use by chained servlets.
    4. *
* @param request May contain or point to the XML XSLTInputSource * @param listener To record detailed parsing messages for possible return to requestor * @return XML XSLTInputSource DOM, or null if the XSLTInputSource could not be parsed * @exception ApplyXSLException Thrown if exception occurs while handling request */ protected XSLTInputSource getDocument(XSLTProcessor processor, HttpServletRequest request, ApplyXSLListener listener) throws ApplyXSLException { try { String xmlURL = null; // document from PathInfo if ((xmlURL = request.getPathInfo()) != null) { listener.out.println("Parsing XML Document from PathInfo: " + xmlURL); return makeDocument(processor, request, new URL("http", ((DefaultApplyXSLProperties) ourDefaultParameters).getLocalHost(), xmlURL.replace('\\', '/')).openStream(), listener); } // document from Request parameter if ((xmlURL = ourDefaultParameters.getXMLurl(request)) != null) { listener.out.println("Parsing XML Document from request parameter: " + xmlURL); return makeDocument(processor, request, new URL(xmlURL).openStream(), listener); } // document from chain String contentType = request.getContentType(); if ((contentType != null) && contentType.startsWith("text/xml")) { listener.out.println("Parsing XML Document from request chain"); return makeDocument(processor, request, request.getInputStream(), listener); } } catch (IOException ioe) { throw new ApplyXSLException(ioe, HttpServletResponse.SC_NOT_FOUND); } catch (Exception e) { throw new ApplyXSLException(e, HttpServletResponse.SC_INTERNAL_SERVER_ERROR); } return null; } /** * The attribute name in the tag used in stylesheet selection. */ protected static final String STYLESHEET_ATTRIBUTE = "media"; /** * The HTTP Header used for matching the Stylesheet attribute via the * media properties file selected. */ protected static final String HEADER_NAME = "user-Agent"; } /** * Stores the keys and values from a file (similar to a properties file) and * can return the first value which has a key contained in its string. * File can have comment lines starting with '#" and for each line the entries are * separated by tabs and '=' char. */ class OrderedProps { /** * Stores the Key and Values as an array of Strings */ private Vector attVec = new Vector(15); /** * Constructor. * @param inputStream Stream containing the properties file. * @exception IOException Thrown if unable to read from stream */ OrderedProps(InputStream inputStream) throws IOException { BufferedReader input = new BufferedReader(new InputStreamReader(inputStream)); String currentLine, Key = null; StringTokenizer currentTokens; while ((currentLine = input.readLine()) != null) { currentTokens = new StringTokenizer(currentLine, "=\t\r\n"); if (currentTokens.hasMoreTokens()) Key = currentTokens.nextToken().trim(); if ((Key != null) && !Key.startsWith("#") && currentTokens.hasMoreTokens()) { String temp[] = new String[2]; temp[0] = Key; temp[1] = currentTokens.nextToken().trim(); attVec.addElement(temp); } } } /** * Iterates through the Key list and returns the first value for whose * key the given string contains. Returns "unknown" if no key is contained * in the string. * @param s String being searched for a key. * @return Value for key found in string, otherwise "unknown" */ String getValue(String s) { int i, j = attVec.size(); for (i = 0; i < j; i++) { String temp[] = (String[]) attVec.elementAt(i); if (s.indexOf(temp[0]) > -1) return temp[1]; } return "unknown"; } } /** * Parses a processing instruction's (PI) attributes for easy retrieval. */ class PIA { private Hashtable piAttributes = null; /** * Constructor. * @param pi The processing instruction whose attributes are to be parsed */ PIA(ProcessingInstruction pi) { piAttributes = new Hashtable(); StringTokenizer tokenizer = new StringTokenizer(pi.getNodeValue(), "=\""); while(tokenizer.hasMoreTokens()) { piAttributes.put(tokenizer.nextToken().trim(), tokenizer.nextToken().trim()); } } /** * Returns value of specified attribute. * @param name Attribute name * @return Attribute value, or null if the attribute name does not exist */ String getAttribute(String name) { return (String) piAttributes.get(name); } }