Lucene Related (TBD) 24 Mar 2014

public static FSDirectory open(File path, LockFactory lockFactory) throws IOException {
  if ((Constants.WINDOWS || Constants.SUN_OS || Constants.LINUX)
          && Constants.JRE_IS_64BIT && MMapDirectory.UNMAP_SUPPORTED) {    // UNMAP_SUPPORTED主要判断是否是Sun的jvm实现
    return new MMapDirectory(path, lockFactory);
  } else if (Constants.WINDOWS) {
    return new SimpleFSDirectory(path, lockFactory);
  } else {
    return new NIOFSDirectory(path, lockFactory);
  }
}

/** Index all text files under a directory.
 * <p>
 * This is a command-line application demonstrating simple Lucene indexing.
 * Run it with no command-line arguments for usage information.
 */
public class IndexFiles {
   
  private IndexFiles() {}
 
  /** Index all text files under a directory. */
  public static void main(String[] args) {
    String usage = "java org.apache.lucene.demo.IndexFiles"
                 + " [-index INDEX_PATH] [-docs DOCS_PATH] [-update]\n\n"
                 + "This indexes the documents in DOCS_PATH, creating a Lucene index"
                 + "in INDEX_PATH that can be searched with SearchFiles";
    String indexPath = "index";
    String docsPath = null;
    boolean create = true;
    for (int i = 0; i < args.length; i++) {
      if ("-index".equals(args[i])) {
        indexPath = args[i+1];
        i++;
      } else if ("-docs".equals(args[i])) {
        docsPath = args[i+1];
        i++;
      } else if ("-update".equals(args[i])) {
        create = false;
      }
    }
 
    if (docsPath == null) {
      System.err.println("Usage: " + usage);
      System.exit(1);
    }
 
    final File docDir = new File(docsPath);
    if (!docDir.exists() || !docDir.canRead()) {
      System.out.println("Document directory '" +docDir.getAbsolutePath()+ 
                     "' does not exist or is not readable, please check the path");
      System.exit(1);
    }
     
    Date start = new Date();
    try {
      System.out.println("Indexing to directory '" + indexPath + "'...");
 
      Directory dir = FSDirectory.open(new File(indexPath));
      Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_40);
      IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_40, analyzer);
 
      if (create) {
        // Create a new index in the directory, removing any
        // previously indexed documents:
        iwc.setOpenMode(OpenMode.CREATE);
      } else {
        // Add new documents to an existing index:
        iwc.setOpenMode(OpenMode.CREATE_OR_APPEND);
      }
 
      // Optional: for better indexing performance, if you
      // are indexing many documents, increase the RAM
      // buffer.  But if you do this, increase the max heap
      // size to the JVM (eg add -Xmx512m or -Xmx1g):
      //
      // iwc.setRAMBufferSizeMB(256.0);
 
      IndexWriter writer = new IndexWriter(dir, iwc);
      indexDocs(writer, docDir);
 
      // NOTE: if you want to maximize search performance,
      // you can optionally call forceMerge here.  This can be
      // a terribly costly operation, so generally it's only
      // worth it when your index is relatively static (ie
      // you're done adding documents to it):
      //
      // writer.forceMerge(1);
 
      writer.close();
 
      Date end = new Date();
      System.out.println(end.getTime() - start.getTime() + " total milliseconds");
 
    } catch (IOException e) {
      System.out.println(" caught a " + e.getClass() +
       "\n with message: " + e.getMessage());
    }
  }
 
  /**
   * Indexes the given file using the given writer, or if a directory is given,
   * recurses over files and directories found under the given directory.
   *
   * NOTE: This method indexes one document per input file.  This is slow.  For good
   * throughput, put multiple documents into your input file(s).  An example of this is
   * in the benchmark module, which can create "line doc" files, one document per line,
   * using the
   * <a href="../../../../../contrib-benchmark/org/apache/lucene/benchmark/byTask/tasks/WriteLineDocTask.html"
   * >WriteLineDocTask</a>.
   * 
   * @param writer Writer to the index where the given file/dir info will be stored
   * @param file The file to index, or the directory to recurse into to find files to index
   * @throws IOException If there is a low-level I/O error
   */
  static void indexDocs(IndexWriter writer, File file)
    throws IOException {
    // do not try to index files that cannot be read
    if (file.canRead()) {
      if (file.isDirectory()) {
        String[] files = file.list();
        // an IO error could occur
        if (files != null) {
          for (int i = 0; i < files.length; i++) {
            indexDocs(writer, new File(file, files[i]));
          }
        }
      } else {
 
        FileInputStream fis;
        try {
          fis = new FileInputStream(file);
        } catch (FileNotFoundException fnfe) {
          // at least on windows, some temporary files raise this exception with an "access denied" message
          // checking if the file can be read doesn't help
          return;
        }
 
        try {
 
          // make a new, empty document
          Document doc = new Document();
 
          // Add the path of the file as a field named "path".  Use a
          // field that is indexed (i.e. searchable), but don't tokenize
          // the field into separate words and don't index term frequency
          // or positional information:
          Field pathField = new StringField("path", file.getPath(), Field.Store.YES);
          doc.add(pathField);
 
          // Add the last modified date of the file a field named "modified".
          // Use a LongField that is indexed (i.e. efficiently filterable with
          // NumericRangeFilter).  This indexes to milli-second resolution, which
          // is often too fine.  You could instead create a number based on
          // year/month/day/hour/minutes/seconds, down the resolution you require.
          // For example the long value 2011021714 would mean
          // February 17, 2011, 2-3 PM.
          doc.add(new LongField("modified", file.lastModified(), Field.Store.NO));
 
          // Add the contents of the file to a field named "contents".  Specify a Reader,
          // so that the text of the file is tokenized and indexed, but not stored.
          // Note that FileReader expects the file to be in UTF-8 encoding.
          // If that's not the case searching for special characters will fail.
          doc.add(new TextField("contents", new BufferedReader(new InputStreamReader(fis, "UTF-8"))));
 
          if (writer.getConfig().getOpenMode() == OpenMode.CREATE) {
            // New index, so we just add the document (no old document can be there):
            System.out.println("adding " + file);
            writer.addDocument(doc);
          } else {
            // Existing index (an old copy of this document may have been indexed) so
            // we use updateDocument instead to replace the old one matching the exact
            // path, if present:
            System.out.println("updating " + file);
            writer.updateDocument(new Term("path", file.getPath()), doc);
          }
           
        } finally {
          fis.close();
        }
      }
    }
  }
} 

TermQuery tq = new TermQuery(new Term("fieldName", "term"));

// 多短语查询
MultiPhraseQuery query = new MultiPhraseQuery();
query.add(new Term("title", "a"));
Term t1 = new Term("title","b");
Term t2 = new Term("title","c");
Term t2 = new Term("title","d");
query.add(new Term[]{t1, t2, t3});
query.add(new Term("title", "e"));
 
// 短语查询实现
PhraseQuery query1 = new PhraseQuery();
query1.add(new Term("title", "a"));
query1.add(new Term("title", "b"));
query1.add(new Term("title", "e"));
 
PhraseQuery query2 = new PhraseQuery();
query2.add(new Term("title", "a"));
query2.add(new Term("title", "c"));
query2.add(new Term("title", "e"));
 
PhraseQuery query3 = new PhraseQuery();
query3.add(new Term("title", "a"));
query3.add(new Term("title", "d"));
query3.add(new Term("title", "e"));
 
BooleanQuery query = new BooleanQuery();
query.add(query1, SHOULD);
query.add(query2, SHOULD);
query.add(query3, SHOULD);

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Date;
 
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;
 
/** Simple command-line based search demo. */
public class SearchFiles {
 
  private SearchFiles() {}
 
  /** Simple command-line based search demo. */
  public static void main(String[] args) throws Exception {
    String usage =
      "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.";
    if (args.length > 0 && ("-h".equals(args[0]) || "-help".equals(args[0]))) {
      System.out.println(usage);
      System.exit(0);
    }
 
    String index = "index";
    String field = "contents";
    String queries = null;
    int repeat = 0;
    boolean raw = false;
    String queryString = null;
    int hitsPerPage = 10;
     
    for(int i = 0;i < args.length;i++) {
      if ("-index".equals(args[i])) {
        index = args[i+1];
        i++;
      } else if ("-field".equals(args[i])) {
        field = args[i+1];
        i++;
      } else if ("-queries".equals(args[i])) {
        queries = args[i+1];
        i++;
      } else if ("-query".equals(args[i])) {
        queryString = args[i+1];
        i++;
      } else if ("-repeat".equals(args[i])) {
        repeat = Integer.parseInt(args[i+1]);
        i++;
      } else if ("-raw".equals(args[i])) {
        raw = true;
      } else if ("-paging".equals(args[i])) {
        hitsPerPage = Integer.parseInt(args[i+1]);
        if (hitsPerPage <= 0) {
          System.err.println("There must be at least 1 hit per page.");
          System.exit(1);
        }
        i++;
      }
    }
     
    IndexReader reader = DirectoryReader.open(FSDirectory.open(new File(index)));
    IndexSearcher searcher = new IndexSearcher(reader);
    Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_40);
 
    BufferedReader in = null;
    if (queries != null) {
      in = new BufferedReader(new InputStreamReader(new FileInputStream(queries), "UTF-8"));
    } else {
      in = new BufferedReader(new InputStreamReader(System.in, "UTF-8"));
    }
    QueryParser parser = new QueryParser(Version.LUCENE_40, field, analyzer);
    while (true) {
      if (queries == null && queryString == null) {                        // prompt the user
        System.out.println("Enter query: ");
      }
 
      String line = queryString != null ? queryString : in.readLine();
 
      if (line == null || line.length() == -1) {
        break;
      }
 
      line = line.trim();
      if (line.length() == 0) {
        break;
      }
       
      Query query = parser.parse(line);
      System.out.println("Searching for: " + query.toString(field));
             
      if (repeat > 0) {                           // repeat & time as benchmark
        Date start = new Date();
        for (int i = 0; i < repeat; i++) {
          searcher.search(query, null, 100);
        }
        Date end = new Date();
        System.out.println("Time: "+(end.getTime()-start.getTime())+"ms");
      }
 
      doPagingSearch(in, searcher, query, hitsPerPage, raw, queries == null && queryString == null);
 
      if (queryString != null) {
        break;
      }
    }
    reader.close();
  }
 
  /**
   * 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.
   *
   */
  public static void doPagingSearch(BufferedReader in, IndexSearcher searcher, Query query,
                                     int hitsPerPage, boolean raw, boolean interactive) throws IOException {
  
    // Collect enough docs to show 5 pages
    TopDocs results = searcher.search(query, 5 * hitsPerPage);
    ScoreDoc[] hits = results.scoreDocs;
     
    int numTotalHits = results.totalHits;
    System.out.println(numTotalHits + " total matching documents");
 
    int start = 0;
    int end = Math.min(numTotalHits, hitsPerPage);
         
    while (true) {
      if (end > hits.length) {
        System.out.println("Only results 1 - " + hits.length +" of "
                              + numTotalHits + " total matching documents collected.");
        System.out.println("Collect more (y/n) ?");
        String line = in.readLine();
        if (line.length() == 0 || line.charAt(0) == 'n') {
          break;
        }
 
        hits = searcher.search(query, numTotalHits).scoreDocs;
      }
       
      end = Math.min(hits.length, start + hitsPerPage);
       
      for (int i = start; i < end; i++) {
        if (raw) {                              // output raw format
          System.out.println("doc="+hits[i].doc+" score="+hits[i].score);
          continue;
        }
 
        Document doc = searcher.doc(hits[i].doc);
        String path = doc.get("path");
        if (path != null) {
          System.out.println((i+1) + ". " + path);
          String title = doc.get("title");
          if (title != null) {
            System.out.println("   Title: " + doc.get("title"));
          }
        } else {
          System.out.println((i+1) + ". " + "No path for this document");
        }
                   
      }
 
      if (!interactive || end == 0) {
        break;
      }
 
      if (numTotalHits >= end) {
        boolean quit = false;
        while (true) {
          System.out.print("Press ");
          if (start - hitsPerPage >= 0) {
            System.out.print("(p)revious page, "); 
          }
          if (start + hitsPerPage < numTotalHits) {
            System.out.print("(n)ext page, ");
          }
          System.out.println("(q)uit or enter number to jump to a page.");
           
          String line = in.readLine();
          if (line.length() == 0 || line.charAt(0)=='q') {
            quit = true;
            break;
          }
          if (line.charAt(0) == 'p') {
            start = Math.max(0, start - hitsPerPage);
            break;
          } else if (line.charAt(0) == 'n') {
            if (start + hitsPerPage < numTotalHits) {
              start+=hitsPerPage;
            }
            break;
          } else {
            int page = Integer.parseInt(line);
            if ((page - 1) * hitsPerPage < numTotalHits) {
              start = (page - 1) * hitsPerPage;
              break;
            } else {
              System.out.println("No such page");
            }
          }
        }
        if (quit) break;
        end = Math.min(numTotalHits, start + hitsPerPage);
      }
    }
  }
}