lucene全文检索的简单使用-----（版本4.3） 摘自api

1. 创建索引

001    package org.apache.lucene.demo;
002    
003    /*
004     * Licensed to the Apache Software Foundation (ASF) under one or more
005     * contributor license agreements.  See the NOTICE file distributed with
006     * this work for additional information regarding copyright ownership.
007     * The ASF licenses this file to You under the Apache License, Version 2.0
008     * (the "License"); you may not use this file except in compliance with
009     * the License.  You may obtain a copy of the License at
010     *
011     *     http://www.apache.org/licenses/LICENSE-2.0
012     *
013     * Unless required by applicable law or agreed to in writing, software
014     * distributed under the License is distributed on an "AS IS" BASIS,
015     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016     * See the License for the specific language governing permissions and
017     * limitations under the License.
018     */
019    
020    import org.apache.lucene.analysis.Analyzer;
021    import org.apache.lucene.analysis.standard.StandardAnalyzer;
022    import org.apache.lucene.document.Document;
023    import org.apache.lucene.document.Field;
024    import org.apache.lucene.document.LongField;
025    import org.apache.lucene.document.StringField;
026    import org.apache.lucene.document.TextField;
027    import org.apache.lucene.index.IndexWriter;
028    import org.apache.lucene.index.IndexWriterConfig.OpenMode;
029    import org.apache.lucene.index.IndexWriterConfig;
030    import org.apache.lucene.index.Term;
031    import org.apache.lucene.store.Directory;
032    import org.apache.lucene.store.FSDirectory;
033    import org.apache.lucene.util.Version;
034    
035    import java.io.BufferedReader;
036    import java.io.File;
037    import java.io.FileInputStream;
038    import java.io.FileNotFoundException;
039    import java.io.IOException;
040    import java.io.InputStreamReader;
041    import java.util.Date;
042    
043    /** Index all text files under a directory.
044     * <p>
045     * This is a command-line application demonstrating simple Lucene indexing.
046     * Run it with no command-line arguments for usage information.
047     */
048    public class IndexFiles {
049      
050      private IndexFiles() {}
051    
052      /** Index all text files under a directory. */
053      public static void main(String[] args) {
054        String usage = "java org.apache.lucene.demo.IndexFiles"
055                     + " [-index INDEX_PATH] [-docs DOCS_PATH] [-update]\n\n"
056                     + "This indexes the documents in DOCS_PATH, creating a Lucene index"
057                     + "in INDEX_PATH that can be searched with SearchFiles";
058        String indexPath = "index";
059        String docsPath = null;
060        boolean create = true;
061        for(int i=0;i<args.length;i++) {
062          if ("-index".equals(args[i])) {
063            indexPath = args[i+1];
064            i++;
065          } else if ("-docs".equals(args[i])) {
066            docsPath = args[i+1];
067            i++;
068          } else if ("-update".equals(args[i])) {
069            create = false;
070          }
071        }
072    
073        if (docsPath == null) {
074          System.err.println("Usage: " + usage);
075          System.exit(1);
076        }
077    
078        final File docDir = new File(docsPath);
079        if (!docDir.exists() || !docDir.canRead()) {
080          System.out.println("Document directory '" +docDir.getAbsolutePath()+ "' does not exist or is not readable, please check the path");
081          System.exit(1);
082        }
083        
084        Date start = new Date();
085        try {
086          System.out.println("Indexing to directory '" + indexPath + "'...");
087    
088          Directory dir = FSDirectory.open(new File(indexPath));
089          Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_40);
090          IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_40, analyzer);
091    
092          if (create) {
093            // Create a new index in the directory, removing any
094            // previously indexed documents:
095            iwc.setOpenMode(OpenMode.CREATE);
096          } else {
097            // Add new documents to an existing index:
098            iwc.setOpenMode(OpenMode.CREATE_OR_APPEND);
099          }
100    
101          // Optional: for better indexing performance, if you
102          // are indexing many documents, increase the RAM
103          // buffer.  But if you do this, increase the max heap
104          // size to the JVM (eg add -Xmx512m or -Xmx1g):
105          //
106          // iwc.setRAMBufferSizeMB(256.0);
107    
108          IndexWriter writer = new IndexWriter(dir, iwc);
109          indexDocs(writer, docDir);
110    
111          // NOTE: if you want to maximize search performance,
112          // you can optionally call forceMerge here.  This can be
113          // a terribly costly operation, so generally it's only
114          // worth it when your index is relatively static (ie
115          // you're done adding documents to it):
116          //
117          // writer.forceMerge(1);
118    
119          writer.close();
120    
121          Date end = new Date();
122          System.out.println(end.getTime() - start.getTime() + " total milliseconds");
123    
124        } catch (IOException e) {
125          System.out.println(" caught a " + e.getClass() +
126           "\n with message: " + e.getMessage());
127        }
128      }
129    
130      /**
131       * Indexes the given file using the given writer, or if a directory is given,
132       * recurses over files and directories found under the given directory.
133       * 
134       * NOTE: This method indexes one document per input file.  This is slow.  For good
135       * throughput, put multiple documents into your input file(s).  An example of this is
136       * in the benchmark module, which can create "line doc" files, one document per line,
137       * using the
138       * <a href="../../../../../contrib-benchmark/org/apache/lucene/benchmark/byTask/tasks/WriteLineDocTask.html"
139       * >WriteLineDocTask</a>.
140       *  
141       * @param writer Writer to the index where the given file/dir info will be stored
142       * @param file The file to index, or the directory to recurse into to find files to index
143       * @throws IOException If there is a low-level I/O error
144       */
145      static void indexDocs(IndexWriter writer, File file)
146        throws IOException {
147        // do not try to index files that cannot be read
148        if (file.canRead()) {
149          if (file.isDirectory()) {
150            String[] files = file.list();
151            // an IO error could occur
152            if (files != null) {
153              for (int i = 0; i < files.length; i++) {
154                indexDocs(writer, new File(file, files[i]));
155              }
156            }
157          } else {
158    
159            FileInputStream fis;
160            try {
161              fis = new FileInputStream(file);
162            } catch (FileNotFoundException fnfe) {
163              // at least on windows, some temporary files raise this exception with an "access denied" message
164              // checking if the file can be read doesn't help
165              return;
166            }
167    
168            try {
169    
170              // make a new, empty document
171              Document doc = new Document();
172    
173              // Add the path of the file as a field named "path".  Use a
174              // field that is indexed (i.e. searchable), but don't tokenize 
175              // the field into separate words and don't index term frequency
176              // or positional information:
177              Field pathField = new StringField("path", file.getPath(), Field.Store.YES);
178              doc.add(pathField);
179    
180              // Add the last modified date of the file a field named "modified".
181              // Use a LongField that is indexed (i.e. efficiently filterable with
182              // NumericRangeFilter).  This indexes to milli-second resolution, which
183              // is often too fine.  You could instead create a number based on
184              // year/month/day/hour/minutes/seconds, down the resolution you require.
185              // For example the long value 2011021714 would mean
186              // February 17, 2011, 2-3 PM.
187              doc.add(new LongField("modified", file.lastModified(), Field.Store.NO));
188    
189              // Add the contents of the file to a field named "contents".  Specify a Reader,
190              // so that the text of the file is tokenized and indexed, but not stored.
191              // Note that FileReader expects the file to be in UTF-8 encoding.
192              // If that's not the case searching for special characters will fail.
193              doc.add(new TextField("contents", new BufferedReader(new InputStreamReader(fis, "UTF-8"))));
194    
195              if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {
196                // New index, so we just add the document (no old document can be there):
197                System.out.println("adding " + file);
198                writer.addDocument(doc);
199              } else {
200                // Existing index (an old copy of this document may have been indexed) so 
201                // we use updateDocument instead to replace the old one matching the exact 
202                // path, if present:
203                System.out.println("updating " + file);
204                writer.updateDocument(new Term("path", file.getPath()), doc);
205              }
206              
207            } finally {
208              fis.close();
209            }
210          }
211        }
212      }
213    }

2.通过索引查询指定的字段

001    package org.apache.lucene.demo;
002    
003    /*
004     * Licensed to the Apache Software Foundation (ASF) under one or more
005     * contributor license agreements.  See the NOTICE file distributed with
006     * this work for additional information regarding copyright ownership.
007     * The ASF licenses this file to You under the Apache License, Version 2.0
008     * (the "License"); you may not use this file except in compliance with
009     * the License.  You may obtain a copy of the License at
010     *
011     *     http://www.apache.org/licenses/LICENSE-2.0
012     *
013     * Unless required by applicable law or agreed to in writing, software
014     * distributed under the License is distributed on an "AS IS" BASIS,
015     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016     * See the License for the specific language governing permissions and
017     * limitations under the License.
018     */
019    
020    import java.io.BufferedReader;
021    import java.io.File;
022    import java.io.FileInputStream;
023    import java.io.IOException;
024    import java.io.InputStreamReader;
025    import java.util.Date;
026    
027    import org.apache.lucene.analysis.Analyzer;
028    import org.apache.lucene.analysis.standard.StandardAnalyzer;
029    import org.apache.lucene.document.Document;
030    import org.apache.lucene.index.DirectoryReader;
031    import org.apache.lucene.index.IndexReader;
032    import org.apache.lucene.queryparser.classic.QueryParser;
033    import org.apache.lucene.search.IndexSearcher;
034    import org.apache.lucene.search.Query;
035    import org.apache.lucene.search.ScoreDoc;
036    import org.apache.lucene.search.TopDocs;
037    import org.apache.lucene.store.FSDirectory;
038    import org.apache.lucene.util.Version;
039    
040    /** Simple command-line based search demo. */
041    public class SearchFiles {
042    
043      private SearchFiles() {}
044    
045      /** Simple command-line based search demo. */
046      public static void main(String[] args) throws Exception {
047        String usage =
048          "Usage:\tjava org.apache.lucene.demo.SearchFiles [-index dir] [-field f] [-repeat n] [-queries file] [-query string] [-raw] [-paging hitsPerPage]\n\nSee http://lucene.apache.org/core/4_1_0/demo/ for details.";
049        if (args.length > 0 && ("-h".equals(args[0]) || "-help".equals(args[0]))) {
050          System.out.println(usage);
051          System.exit(0);
052        }
053    
054        String index = "index";
055        String field = "contents";
056        String queries = null;
057        int repeat = 0;
058        boolean raw = false;
059        String queryString = null;
060        int hitsPerPage = 10;
061        
062        for(int i = 0;i < args.length;i++) {
063          if ("-index".equals(args[i])) {
064            index = args[i+1];
065            i++;
066          } else if ("-field".equals(args[i])) {
067            field = args[i+1];
068            i++;
069          } else if ("-queries".equals(args[i])) {
070            queries = args[i+1];
071            i++;
072          } else if ("-query".equals(args[i])) {
073            queryString = args[i+1];
074            i++;
075          } else if ("-repeat".equals(args[i])) {
076            repeat = Integer.parseInt(args[i+1]);
077            i++;
078          } else if ("-raw".equals(args[i])) {
079            raw = true;
080          } else if ("-paging".equals(args[i])) {
081            hitsPerPage = Integer.parseInt(args[i+1]);
082            if (hitsPerPage <= 0) {
083              System.err.println("There must be at least 1 hit per page.");
084              System.exit(1);
085            }
086            i++;
087          }
088        }
089        
090        IndexReader reader = DirectoryReader.open(FSDirectory.open(new File(index)));
091        IndexSearcher searcher = new IndexSearcher(reader);
092        Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_40);
093    
094        BufferedReader in = null;
095        if (queries != null) {
096          in = new BufferedReader(new InputStreamReader(new FileInputStream(queries), "UTF-8"));
097        } else {
098          in = new BufferedReader(new InputStreamReader(System.in, "UTF-8"));
099        }
100        QueryParser parser = new QueryParser(Version.LUCENE_40, field, analyzer);
101        while (true) {
102          if (queries == null && queryString == null) {                        // prompt the user
103            System.out.println("Enter query: ");
104          }
105    
106          String line = queryString != null ? queryString : in.readLine();
107    
108          if (line == null || line.length() == -1) {
109            break;
110          }
111    
112          line = line.trim();
113          if (line.length() == 0) {
114            break;
115          }
116          
117          Query query = parser.parse(line);
118          System.out.println("Searching for: " + query.toString(field));
119                
120          if (repeat > 0) {                           // repeat & time as benchmark
121            Date start = new Date();
122            for (int i = 0; i < repeat; i++) {
123              searcher.search(query, null, 100);
124            }
125            Date end = new Date();
126            System.out.println("Time: "+(end.getTime()-start.getTime())+"ms");
127          }
128    
129          doPagingSearch(in, searcher, query, hitsPerPage, raw, queries == null && queryString == null);
130    
131          if (queryString != null) {
132            break;
133          }
134        }
135        reader.close();
136      }
137    
138      /**
139       * This demonstrates a typical paging search scenario, where the search engine presents 
140       * pages of size n to the user. The user can then go to the next page if interested in
141       * the next hits.
142       * 
143       * When the query is executed for the first time, then only enough results are collected
144       * to fill 5 result pages. If the user wants to page beyond this limit, then the query
145       * is executed another time and all hits are collected.
146       * 
147       */
148      public static void doPagingSearch(BufferedReader in, IndexSearcher searcher, Query query, 
149                                         int hitsPerPage, boolean raw, boolean interactive) throws IOException {
150     
151        // Collect enough docs to show 5 pages
152        TopDocs results = searcher.search(query, 5 * hitsPerPage);
153        ScoreDoc[] hits = results.scoreDocs;
154        
155        int numTotalHits = results.totalHits;
156        System.out.println(numTotalHits + " total matching documents");
157    
158        int start = 0;
159        int end = Math.min(numTotalHits, hitsPerPage);
160            
161        while (true) {
162          if (end > hits.length) {
163            System.out.println("Only results 1 - " + hits.length +" of " + numTotalHits + " total matching documents collected.");
164            System.out.println("Collect more (y/n) ?");
165            String line = in.readLine();
166            if (line.length() == 0 || line.charAt(0) == 'n') {
167              break;
168            }
169    
170            hits = searcher.search(query, numTotalHits).scoreDocs;
171          }
172          
173          end = Math.min(hits.length, start + hitsPerPage);
174          
175          for (int i = start; i < end; i++) {
176            if (raw) {                              // output raw format
177              System.out.println("doc="+hits[i].doc+" score="+hits[i].score);
178              continue;
179            }
180    
181            Document doc = searcher.doc(hits[i].doc);
182            String path = doc.get("path");
183            if (path != null) {
184              System.out.println((i+1) + ". " + path);
185              String title = doc.get("title");
186              if (title != null) {
187                System.out.println("   Title: " + doc.get("title"));
188              }
189            } else {
190              System.out.println((i+1) + ". " + "No path for this document");
191            }
192                      
193          }
194    
195          if (!interactive || end == 0) {
196            break;
197          }
198    
199          if (numTotalHits >= end) {
200            boolean quit = false;
201            while (true) {
202              System.out.print("Press ");
203              if (start - hitsPerPage >= 0) {
204                System.out.print("(p)revious page, ");  
205              }
206              if (start + hitsPerPage < numTotalHits) {
207                System.out.print("(n)ext page, ");
208              }
209              System.out.println("(q)uit or enter number to jump to a page.");
210              
211              String line = in.readLine();
212              if (line.length() == 0 || line.charAt(0)=='q') {
213                quit = true;
214                break;
215              }
216              if (line.charAt(0) == 'p') {
217                start = Math.max(0, start - hitsPerPage);
218                break;
219              } else if (line.charAt(0) == 'n') {
220                if (start + hitsPerPage < numTotalHits) {
221                  start+=hitsPerPage;
222                }
223                break;
224              } else {
225                int page = Integer.parseInt(line);
226                if ((page - 1) * hitsPerPage < numTotalHits) {
227                  start = (page - 1) * hitsPerPage;
228                  break;
229                } else {
230                  System.out.println("No such page");
231                }
232              }
233            }
234            if (quit) break;
235            end = Math.min(numTotalHits, start + hitsPerPage);
236          }
237        }
238      }
239    }