Java tutorial
package com.revorg.goat; /* * Copyright (c) Grover C. Fields, http://www.groverfields.com/, 2005-2009. * All rights reserved. Software written by Grover C. Fields and others. * $Id: LICENSE,v 1.0 2008/12/01 05:00:00 Grover Exp $ * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * Java, the Duke mascot, and all variants of Sun's Java "steaming coffee * cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's, * pioneering role in inventing and promulgating (and standardizing) the Java * language and environment is gratefully acknowledged. * * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for * inventing predecessor languages C and C++ is also gratefully acknowledged. */ import java.io.IOException; import org.apache.lucene.analysis.standard.StandardAnalyzer; import org.apache.lucene.document.Document; import org.apache.lucene.index.IndexReader; import org.apache.lucene.index.IndexWriter; import org.apache.lucene.queryParser.MultiFieldQueryParser; import org.apache.lucene.queryParser.QueryParser; import org.apache.lucene.search.IndexSearcher; import org.apache.lucene.search.Query; import org.apache.lucene.search.ScoreDoc; import org.apache.lucene.search.Searcher; import org.apache.lucene.search.Sort; import org.apache.lucene.search.SortField; import org.apache.lucene.search.TopFieldDocs; import java.util.HashMap; import java.util.Map; /** * This class searches the Lucene Database Collections * * @version 1.0 * @author Grover C. Fields (grover_fields@yahoo.com) * @author http://www.groverfields.com */ public class SearchDatabase implements java.io.Serializable { private static String ActionResult; private static String ActionResultError; private static IndexReader reader; private static IndexWriter writer; private static IndexSearcher searcher; public SearchDatabase() { } /** * Searches the Lucene index based on file system documents. * * @param indexPath Directory that contains the Lucene Collection * @param hitsPerPage Number of hits per page * @param pageNum The page number to search * @param searchString The search string for searching * @param searchType The type of results to return * @param sortField The field to sort on if needed * @param sortDirection The direction to sort by * @throws Exception * @return ActionResult */ public static String doSingleSearch(String indexPath, int hitsPerPage, int pageNum, String searchString, String searchType, String sortField, String sortDirection) { try { if (searchString != null) searchString.trim().toLowerCase(); //Lower Case Search IndexReader reader = IndexReader.open(indexPath); IndexSearcher searcher = new IndexSearcher(indexPath); if (searcher == null) { throw new Exception("Unable to open index"); } QueryParser parser = new QueryParser("contents", new StandardAnalyzer()); Query query = parser.parse(searchString); if (query == null) { throw new Exception("Unable to build Query"); } String returnText = ""; returnText = doPagingSearch(indexPath, searcher, query, hitsPerPage, pageNum, searchType, sortField, sortDirection); //System.out.println(returnText); reader.close(); //Paging Results return returnText; } catch (Exception e) { ActionResultError = " caught a " + e.getClass() + " with message: " + e.getMessage(); //System.out.println("Failure of DbSchema File: " + xmlFile); } ActionResult = "Failure"; return ActionResult + ActionResultError; } /** * Searches the Lucene index based on database documents. * * @param indexPath Directory that contains the Lucene Collection * @param hitsPerPage Number of hits per page * @param pageNum The page number to search * @param searchString The search string for searching * @param searchType The type of results to return * @param sortField The field to sort on if needed * @param sortDirection The direction to sort by * @throws Exception * @return ActionResult */ public static String doMultiSearch(String indexPath, int hitsPerPage, int pageNum, String searchFieldsArray[], String searchString, String searchType, String sortField, String sortDirection) { try { if (searchString != null) searchString.trim().toLowerCase(); //Lower Case Search IndexReader reader = IndexReader.open(indexPath); IndexSearcher searcher = new IndexSearcher(indexPath); if (searcher == null) { throw new Exception("Unable to open index"); } QueryParser parser = new MultiFieldQueryParser(searchFieldsArray, new StandardAnalyzer()); Query query = parser.parse(searchString); if (query == null) { throw new Exception("Unable to build Query"); } String returnText = ""; returnText = doPagingSearch(indexPath, searcher, query, hitsPerPage, pageNum, searchType, sortField, sortDirection); //System.out.println(returnText); reader.close(); //Paging Results return returnText; } catch (Exception e) { ActionResultError = " caught a " + e.getClass() + " with message: " + e.getMessage(); //System.out.println("Failure of DbSchema File: " + xmlFile); } ActionResult = "Failure"; return ActionResult + ActionResultError; } /** * This demonstrates a typical paging search scenario, where the search engine presents * pages of size n to the user. The user can then go to the next page if interested in * the next hits. * * When the query is executed for the first time, then only enough results are collected * to fill 5 result pages. If the user wants to page beyond this limit, then the query * is executed another time and all hits are collected. * * @param indexPath Directory that contains the Lucene Collection * @param searcher The searcher used by Lucene * @param hitsPerPage Number of hits per page * @param pageNum The page number to search * @param searchType The type of results to return * @param sortField The field to sort on if needed * @param sortDirection The direction to sort by * @throws Exception * @return ActionResult */ private static String doPagingSearch(String indexPath, Searcher searcher, Query query, int hitsPerPage, int pageNum, String searchType, String sortField, String sortDirection) throws Exception { try { XMLReader readerXML = new XMLReader(); //XML Reader Class String configFile = ConfigFiles.getSchemaFile(indexPath); String[] indexTypeArray = new String[Integer.parseInt(readerXML.getTotalNodes(configFile))]; String[] columnNamesArray = new String[Integer.parseInt(readerXML.getTotalNodes(configFile))]; int totalNodes = columnNamesArray.length; String textResultSet = ""; String nodeName = ""; //Sort .:. Index Type must be PrimaryKey,Keyword,Date Sort sortby = new Sort(); if (sortField != null) sortField.trim().toLowerCase(); //Change Field TO LowerCase //Get Column Names for (int i = 0; i < totalNodes; i++) { columnNamesArray[i] = readerXML.getNodeValueByFile(configFile, i, "columnname"); indexTypeArray[i] = readerXML.getNodeValueByFile(configFile, i, "indextype"); /* Make Sure Field Can Be Seached */ if (columnNamesArray[i].equalsIgnoreCase(sortField) && (indexTypeArray[i].equalsIgnoreCase("PrimaryKey") || indexTypeArray[i].equalsIgnoreCase("Keyword") || indexTypeArray[i].equalsIgnoreCase("Date"))) { //Sort Ascending if (sortDirection != null && sortDirection.equalsIgnoreCase("desc")) { System.out.println("desc"); sortby = new Sort(sortField, true); } else if (sortDirection != null && sortDirection.equalsIgnoreCase("asc")) { System.out.println("asc"); sortby = new Sort(sortField, false); } } } if (hitsPerPage == 0) hitsPerPage = 1; int recordSet = (pageNum * hitsPerPage) + 100; //VERSION 1 OF SIMPLE RESULT SET // Collect enough docs to show 5 pages //TopDocCollector collector = new TopDocCollector((pageNum * hitsPerPage)+100); //searcher.search(query, collector); //ScoreDoc[] hits = collector.topDocs().scoreDocs; //int numTotalHits = collector.getTotalHits(); TopFieldDocs resultDocs = searcher.search(query, null, recordSet, sortby); ScoreDoc[] hits = resultDocs.scoreDocs; int numTotalHits = resultDocs.totalHits; //Start int start = (pageNum - 1); if (start < 0) start = 0; if (pageNum > 1) { start = (pageNum * hitsPerPage) - hitsPerPage; } int end = (pageNum * hitsPerPage); if (searchType.equalsIgnoreCase("xml") && numTotalHits == 0) { textResultSet = "<?xml version=\"1.0\" encoding=\"utf-8\"?>" + System.getProperty("line.separator"); textResultSet = textResultSet + "<goaterror>\n" + " <error type=\"noresults\" code=\"1.1\">\n" + " <title>Dang. We didn't find anything for you there.</title>\n" + " <text>\n" + " <p> We couldn't find any result for <strong>" + query + "</strong>.</p>\n" + " </text>\n" + " </error>\n" + "</goaterror>"; return textResultSet; } if (searchType.equalsIgnoreCase("xml") && numTotalHits > 0) { textResultSet = "<?xml version=\"1.0\" encoding=\"utf-8\"?>" + System.getProperty("line.separator"); textResultSet = textResultSet + "<resultset>" + System.getProperty("line.separator"); textResultSet = textResultSet + "<searchterm><![CDATA[" + query + "]]></searchterm>" + System.getProperty("line.separator"); textResultSet = textResultSet + "<start>" + (start + 1) + "</start>" + System.getProperty("line.separator"); textResultSet = textResultSet + "<end>" + end + "</end>" + System.getProperty("line.separator"); textResultSet = textResultSet + "<totalresults>" + numTotalHits + "</totalresults>" + System.getProperty("line.separator"); textResultSet = textResultSet + "<totalpages>" + (numTotalHits / hitsPerPage) + "</totalpages>" + System.getProperty("line.separator"); textResultSet = textResultSet + "<rows>"; } /* * V1 IMPLEMENTATION ALSO if (end > hits.length) { collector = new TopDocCollector(numTotalHits); searcher.search(query, collector); hits = collector.topDocs().scoreDocs; } */ end = Math.min(hits.length, start + hitsPerPage); for (int i = start; i < end; i++) { //Document doc = searcher.doc(hits[i].doc); int docId = hits[i].doc; Document d = searcher.doc(docId); for (int x = 0; x < totalNodes; x++) { nodeName = columnNamesArray[x]; //XML if (searchType.equalsIgnoreCase("xml")) { //System.out.println("i " + i + " x " + x + " Node: " + nodeName); if (x == 0) { textResultSet = textResultSet + System.getProperty("line.separator") + "<row number=\"" + (i + 1) + "\"" + " score=\"" + hits[i].score + "\">"; } textResultSet = textResultSet + "<" + nodeName + "><![CDATA[" + d.get(nodeName) + "]]></" + nodeName + ">"; if (x == totalNodes - 1) { textResultSet = textResultSet + "</row>"; } } else if (searchType.equalsIgnoreCase("primary") && indexTypeArray[x].equalsIgnoreCase("PrimaryKey") == true) { if (textResultSet.length() > 0) textResultSet = textResultSet + ","; textResultSet = textResultSet + d.get(nodeName); } } } //Close if (searchType.equalsIgnoreCase("xml") && numTotalHits > 0 && textResultSet.length() > 0) { textResultSet = textResultSet + "</rows></resultset>" + System.getProperty("line.separator"); } else if (searchType.equalsIgnoreCase("primary") && numTotalHits > 0 && textResultSet.length() > 0) { textResultSet = (numTotalHits) + "|" + (numTotalHits / hitsPerPage) + "|" + textResultSet + System.getProperty("line.separator"); } else { return null; } return textResultSet; } catch (Exception e) { ActionResultError = " caught a " + e.getClass() + " with message: " + e.getMessage(); //System.out.println("Failure of DbSchema File: " + xmlFile); } ActionResult = "Failure"; return ActionResult + ActionResultError; } }