<%@ page import = "  javax.servlet.*, javax.servlet.http.*, java.io.*, org.apache.lucene.analysis.*, org.apache.lucene.analysis.standard.StandardAnalyzer, org.apache.lucene.document.*, org.apache.lucene.index.*, org.apache.lucene.search.*, org.apache.lucene.queryParser.*, org.apache.lucene.demo.*, org.apache.lucene.demo. html.Entities, java.net.URLEncoder" %>
002 
003 <%
004 /*
005         Author: Andrew C. Oliver, SuperLink Software, Inc. (acoliver2@users.     sourceforge.net)
006 
007         This jsp page is deliberatly written in the horrible java directly     embedded
008         in the page style for an easy and concise demonstration of Lucene.
009         Due note...if you write pages that look like this...sooner or later
010         you'll have a maintenance nightmare.  If you use jsps...use taglibs
011         and beans!  That being said, this should be acceptable for a small
012         page demonstrating how one uses Lucene in a web app.
013 
014         This is also deliberately overcommented. ;-)
015 
016 */
017 %>
018 <%!
019 public String escapeHTML(String s) {
020   s = s.replaceAll("&", "&amp;");
021   s = s.replaceAll("<", "&lt;");
022   s = s.replaceAll(">", "&gt;");
023   s = s.replaceAll("\"", "&quot;");
024   s = s.replaceAll("'", "&apos;");
025   return s;
026 }
027 %>
028 <%@includefile="header.jsp"%>
029 <%
030    boolean error = false;          //used to control flow for error messages
031    String indexName = indexLocation; //local copy of the configuration variable
032    IndexSearcher searcher = null;      //the searcher used to open/search the index
033    Query query = null;          //the Query created by the QueryParser
034    Hits hits = null;               //the search results
035    int startindex = 0;            //the first index displayed on this page
036    int maxpage    = 50;           //the maximum items displayed on this page
037    String queryString = null;     //the query entered in the previous page
038    String startVal    = null;      //string version of startindex
039    String maxresults  = null;     //string version of maxpage
040    int thispage = 0;          //used for the for/next either maxpage or
041                                     //hits.length() - startindex - whichever is
042                                    //less
043 
044         try {
045     searcher = new IndexSearcher(indexName);//create an indexSearcher for our page
046                                  //NOTE: this operation is slow for large
047                                   //indices (much slower than the search itself)
048                                     //so you might want to keep an IndexSearcher
049                                    //open
050                                                        
051         } catch (Exception e) {  //any error that happens is probably due
052                                    //to a permission problem or non-existant
053                                  //or otherwise corrupt index
054 %>
055                 <p>ERROR opening the Index - contact sysadmin!</p>
056                 <p>Error message: <%=escapeHTML(e.getMessage())%></p>  
057 <%                error = true;       //don't do anything up to the footer
058         }
059 %>
060 <%
061        if (error == false) {        //did we open the index?
062            queryString = request.getParameter("query");   //get the search criteria
063            startVal = request.getParameter("startat");   //get the start index
064            maxresults = request.getParameter("maxresults");  //get max results per page
065            try {
066                maxpage = Integer.parseInt(maxresults);//parse the max results first
067                startindex = Integer.parseInt(startVal);   //then the start index 
068                 } catch (Exception e) { } //we don't care if something happens we'll
069                                         //just start at 0or end at 50
070 
071                
072 
073            if (queryString == null)
074                  throw new ServletException("no query "+   //if you don't have a query then
075                                 "specified");    //you probably played on the
076                                                   //query string so you get the
077                                                      //treatment
078 
079                 Analyzer analyzer = new StandardAnalyzer();  //construct our usual
080                 try {                                             //analyzer

081                         QueryParser qp = new QueryParser("contents", analyzer);
082                         query = qp.parse(queryString);  //parse the query and
083                 } catch (ParseException e) {      //construct the Query
084                                               //object
085                                               //if it's just "operator error"
086                                              //send them a nice error HTML
087                                                                      
088 %>
089        <p>Error while parsing query: <%=escapeHTML(e.get Message())%></p>
090 <%
091                         error = true;        //don't bother with the rest of
092                                                //the page
093                 }
094         }
095 %>
096 <%
097         if (error == false && searcher != null) {   // if we've had no errors
098                                               // searcher != null was to handle
099                                               // a weird compilation bug
100                 thispage = maxpage;     // default last element to maxpage
101                 hits = searcher.search(query);     // run the query
102                 if (hits.length() == 0) {    // if we got no results tell the user
103 %>
104                 <p> I'm sorry I couldn't find what you were looking for. </p>
105 <%
106                 error = true;              // don't bother with the rest of the
107                                                // page
108                 }
109         }
110 
111         if (error == false && searcher != null) {                  
112 %>
113                 <table>
114                 <tr>
115                         <td>Document</td>
116                         <td>Summary</td>
117                 </tr>
118 <%
119                 if ((startindex + maxpage) > hits.length()) {
120                     thispage = hits.length() - startindex;   // set the max index
121                 }          //to maxpage or last actual search result whichever is less
122                            // for each element
123                 for (int i = startindex; i < (thispage + startindex); i++) { 
124 %>
125                 <tr>
126 <%
127                         Document doc = hits.doc(i);      //get the next document
128                         String doctitle = doc.get("title");   //get its title
129                         String url = doc.get("path");    //get its path field
130                         if (url != null && url.startsWith("../webapps/")) { // strip
131                           url = url.substring(10); //off ../webapps prefix if present
132                         }
133                         if ((doctitle == null) || doctitle.equals("")) //use the path
134                                 doctitle = url;  // if it has no title
135                                                               //then output!
136 %>
137                         <td><a href="<%=url%>"><%=doctitle%></a></td>
138                         <td><%=doc.get("summary")%></td>
139                 </tr>
140 <%
141                 }
142 %>
143 <%                if ( (startindex + maxpage) < hits.length()) {   //if there are
144                                                  // more results...display the more link
145 
146                         String moreurl="results.jsp?query=" +
147                           URLEncoder.encode(queryString) + //construct the "more" link
148                               "&amp;maxresults=" + maxpage +
149                               "&amp;startat=" + (startindex + maxpage);
150 %>
151                 <tr>
152                         <td></td><td><a href="<%=moreurl%>">More Results>> </a></td>
153                 </tr>
154 <%
155                 }
156 %>
</table>

158 
159 <%       }                                            //then include our footer.
160          if (searcher != null)
161                 searcher.close();
162 %>
163 <%@includefile="footer.jsp"%>