2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
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14 * See the License for the specific language governing permissions and
15 * limitations under the License.
18 package org.apache.lucene.xmlparser.webdemo;
20 import java.io.BufferedReader;
21 import java.io.IOException;
22 import java.io.InputStream;
23 import java.io.InputStreamReader;
24 import java.util.Enumeration;
25 import java.util.Properties;
26 import java.util.StringTokenizer;
28 import javax.servlet.RequestDispatcher;
29 import javax.servlet.ServletConfig;
30 import javax.servlet.ServletException;
31 import javax.servlet.http.HttpServlet;
32 import javax.servlet.http.HttpServletRequest;
33 import javax.servlet.http.HttpServletResponse;
35 import org.apache.lucene.analysis.Analyzer;
36 import org.apache.lucene.analysis.standard.StandardAnalyzer;
37 import org.apache.lucene.document.Document;
38 import org.apache.lucene.document.Field;
39 import org.apache.lucene.index.CorruptIndexException;
40 import org.apache.lucene.index.IndexWriter;
41 import org.apache.lucene.search.IndexSearcher;
42 import org.apache.lucene.search.Query;
43 import org.apache.lucene.search.ScoreDoc;
44 import org.apache.lucene.search.TopDocs;
45 import org.apache.lucene.store.RAMDirectory;
46 import org.apache.lucene.xmlparser.CorePlusExtensionsParser;
47 import org.apache.lucene.xmlparser.QueryTemplateManager;
49 public class FormBasedXmlQueryDemo extends HttpServlet {
51 private QueryTemplateManager queryTemplateManager;
52 private CorePlusExtensionsParser xmlParser;
53 private IndexSearcher searcher;
54 private Analyzer analyzer=new StandardAnalyzer(org.apache.lucene.util.Version.LUCENE_CURRENT);
57 public void init(ServletConfig config) throws ServletException {
62 //load servlet configuration settings
63 String xslFile=config.getInitParameter("xslFile");
64 String defaultStandardQueryParserField = config.getInitParameter("defaultStandardQueryParserField");
67 //Load and cache choice of XSL query template using QueryTemplateManager
68 queryTemplateManager=new QueryTemplateManager(
69 getServletContext().getResourceAsStream("/WEB-INF/"+xslFile));
71 //initialize an XML Query Parser for use by all threads
72 xmlParser=new CorePlusExtensionsParser(defaultStandardQueryParserField,analyzer);
73 } catch (Exception e) {
74 throw new ServletException("Error loading query template",e);
79 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
80 //Take all completed form fields and add to a Properties object
81 Properties completedFormFields=new Properties();
82 Enumeration pNames = request.getParameterNames();
83 while(pNames.hasMoreElements()){
84 String propName=(String) pNames.nextElement();
85 String value=request.getParameter(propName);
86 if((value!=null)&&(value.trim().length()>0)){
87 completedFormFields.setProperty(propName, value);
93 //Create an XML query by populating template with given user criteria
94 org.w3c.dom.Document xmlQuery=queryTemplateManager.getQueryAsDOM(completedFormFields);
96 //Parse the XML to produce a Lucene query
97 Query query=xmlParser.getQuery(xmlQuery.getDocumentElement());
100 TopDocs topDocs = searcher.search(query,10);
102 //and package the results and forward to JSP
104 ScoreDoc[] sd = topDocs.scoreDocs;
105 Document[] results=new Document[sd.length];
106 for (int i = 0; i < results.length; i++) {
107 results[i]=searcher.doc(sd[i].doc);
108 request.setAttribute("results", results);
111 RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/index.jsp");
112 dispatcher.forward(request,response);
115 throw new ServletException("Error processing query",e);
119 private void openExampleIndex() throws CorruptIndexException, IOException {
121 //Create a RAM-based index from our test data file
122 RAMDirectory rd=new RAMDirectory();
123 IndexWriter writer=new IndexWriter (rd,analyzer,IndexWriter.MaxFieldLength.LIMITED);
124 InputStream dataIn=getServletContext().getResourceAsStream("/WEB-INF/data.tsv");
125 BufferedReader br = new BufferedReader(new InputStreamReader(dataIn));
126 String line = br.readLine();
132 //parse row and create a document
133 StringTokenizer st=new StringTokenizer(line,"\t");
134 Document doc=new Document();
135 doc.add(new Field("location",st.nextToken(),Field.Store.YES,
136 Field.Index.ANALYZED_NO_NORMS));
137 doc.add(new Field("salary",st.nextToken(),Field.Store.YES,
138 Field.Index.ANALYZED_NO_NORMS));
139 doc.add(new Field("type",st.nextToken(),Field.Store.YES,
140 Field.Index.ANALYZED_NO_NORMS));
141 doc.add(new Field("description",st.nextToken(),Field.Store.YES,
142 Field.Index.ANALYZED));
143 writer.addDocument(doc);
150 searcher=new IndexSearcher(rd, true);