Příklad B.2. Servlet generující XUL kód

package cz.vse.rainbow.servlets;

// standard and servlet imports
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

// WS imports
import client.iface.*;
import client.iface.struct.*;
import org.idoox.wasp.Context;
import org.idoox.wasp.MessageAttachment;
import org.idoox.webservice.client.WebService;
import org.idoox.webservice.client.WebServiceLookup;
import org.idoox.webservice.client.WebServiceLookupException;

// servlet which returns information about specific URL 
// as XUL document
// URL should be passed by GET method in "url" parameter
public class XULServlet extends HttpServlet
{
  public void doGet(HttpServletRequest request, 
                    HttpServletResponse response)
    throws IOException, ServletException
    {
      // generate begin of XUL page
      response.setContentType(
        "application/vnd.mozilla.xul+xml; charset=utf-8");
      PrintWriter out = response.getWriter();
      out.println("<?xml version='1.0'?>\n" +
        "<?xml-stylesheet href='chrome://global/skin/' 
                          type='text/css'?>\n" +
        "<window xmlns='http://www.mozilla.org/keymaster/
                        gatekeeper/there.is.only.xul'>\n" +
        "<script type='application/x-javascript'>\n" +
        "function openTopWin( url )\n" +
        "{ window._content.location = url; }\n" +
        "</script>\n" +
        "<tree flex='1'>\n" +
        " <treecols>\n" +
        "   <treecol flex='1'/>\n" +
        "   <treecol flex='1'/>\n" +
        " </treecols>\n" +
        " <treechildren flex='1'>\n");

      String googleHost = "http://api.google.com/search/beta2";
      String metadataHost = 
               "http://rainbow.vse.cz:8000/wasp/Metadata/";
      String lingHost = "http://rainbow.vse.cz:7878";

      try
      {
        //init the lookup
        WebServiceLookup lookup = 
          (WebServiceLookup)Context.getInstance
            ("org.idoox.webservice.client.WebServiceLookup");

        // ask Google for related pages
        GoogleSearchPort serviceGoogle = (GoogleSearchPort)lookup.
          lookup("http://api.google.com/GoogleSearch.wsdl",
                 GoogleSearchPort.class,googleHost);
        GoogleSearchResult r = serviceGoogle.doGoogleSearch
          ("...heslo pro přístup ke službě...", 
           "related:" + request.getParameter("url"), 0, 10, 
           false, "", false, "", "", "");
        out.println("<treeitem container='true' open='true'>\n" +
                    "<treerow>\n" +
                    "<treecell class='treecell-indent' 
                               label='Related pages' 
                               style='font-weight: bold'/>\n" +
                    "</treerow>\n" +
                    "<treechildren>\n");
        for (int i=0; i < r.resultElements.length; i++)
        {
          String title = escapeXML(r.resultElements[i].title);
          String url = escapeXML(r.resultElements[i].URL);
          if (title.equals("")) title = url;
          out.println("<treeitem><treerow>\n" +
                      "<treecell class='treecell-indent' 
                                 style='color: blue' " +
                      "label='" + title + "' " +
                      "onclick=\"openTopWin('" + url + "')\"/>\n" +
                      "</treerow></treeitem>\n");
        }
        if (r.resultElements.length == 0)
        {
          out.println("<treeitem><treerow>\n" +
                      "<treecell class='treecell-indent' 
                                 style='color: blue' " +
                      "label='No related pages'/>\n" +
                      "</treerow></treeitem>\n");
        }
        out.println("</treechildren></treeitem>\n");

        // ask Metadata service for metadata
        Metadata serviceMetadata = (Metadata)lookup.
          lookup("http://rainbow.vse.cz:8000/wasp/Metadata/", 
                 Metadata.class,metadataHost);
        Metalist listtags = new Metalist();
        MetalistHolder objmeta = new MetalistHolder();
        objmeta.setValue(listtags);
        serviceMetadata.getTags(request.getParameter("url"), 
                                objmeta);
        listtags = objmeta.getValue();
        out.println("<treeitem container='true' open='true'>\n" +
                    "<treerow>\n" +
                    "<treecell class='treecell-indent' 
                               label='Metadata' 
                               style='font-weight: bold'/>\n" +
                    "</treerow>\n" +
                    "<treechildren>\n");
        for (int i=0; i< listtags.count; i++)
        {
          String metadata = escapeXML(listtags.metatags[i].name + 
                            ": " + listtags.metatags[i].content);
          out.println("<treeitem><treerow>\n" +
                      "<treecell class='treecell-indent' " +
                      "label='" + metadata + "'/>\n" +
                      "</treerow></treeitem>\n");
        }
        if (listtags.count == 0)
        {
          out.println("<treeitem><treerow>\n" +
                      "<treecell class='treecell-indent' " +
                      "label='No metadata found'/>\n" +
                      "</treerow></treeitem>\n");
        }
        out.println("</treechildren></treeitem>\n");

        // ask Ling service for data
        LingService serviceLing = (LingService)lookup.
          lookup("http://rainbow.vse.cz/support/rb-ling.wsdl", 
                 LingService.class,lingHost);
        String sentences[] = serviceLing.extractSentences
          (request.getParameter("url"));
        out.println("<treeitem container='true' open='true'>\n" +
                    "<treerow>\n" +
                    "<treecell class='treecell-indent' 
                               label='Page indicators' 
                               style='font-weight: bold'/>\n" +
                    "</treerow>\n" +
                    "<treechildren>\n");
        for (int i=0; i<sentences.length; i++)
        {
          out.println("<treeitem><treerow>\n" +
                      "<treecell class='treecell-indent' label='" +
                      escapeXML(sentences[i]) + "'/>\n" +
                      "</treerow></treeitem>\n");
        }
        if (sentences.length == 0)
        {
          out.println("<treeitem><treerow>\n" +
                      "<treecell class='treecell-indent' " +
                      "label='No indicators found'/>\n" +
                      "</treerow></treeitem>\n");
        }
        out.println("</treechildren></treeitem>\n");
      }
      catch (WebServiceLookupException e)
      {
        out.println("Unable to call web-service.");
      }

      out.println("</treechildren></tree>\n</window>\n");
    }

    // escapes XML significant characters by entities
    String escapeXML (String in)
    {
      String out = "";
      for (int i=0; i< in.length(); i++)
      {
        if (in.charAt(i) == '<')
          out += "&lt;";
        else if (in.charAt(i) == '&')
          out += "&amp;";
        else if (in.charAt(i) == '\'')
          out += "&apos;";
        else if (in.charAt(i) == '\"')
          out += "&quot;";
        else
          out += in.charAt(i);
      }
      return out;
    }
}