游子 发表于 2009-2-17 10:58:47

apache

就像每个程序都有一个Hello World来让人体验它一样,lucene也可以很简单的提供一个实例。如下(来自lucene in action的例子)有两个类组成: 一个是建立索引
    import java.io.File;
    import java.io.FileReader;
    import java.io.IOException;
    import java.util.Date;
    import org.apache.lucene.analysis.standard.StandardAnalyzer;
    import org.apache.lucene.document.Document;
    import org.apache.lucene.document.Field;
    import org.apache.lucene.index.IndexWriter;
   
    public class Indexer {
      public static void main(String[] args) throws Exception {
      if (args.length != 2) {
          throw new Exception("Usage: java "   Indexer.class.getName()   " <index dir> <data dir>");
      }
      File indexDir = new File(args);
      File dataDir = new File(args);
      long start = new Date().getTime();
      int numIndexed = index(indexDir, dataDir);
      long end = new Date().getTime();
      System.out.println("Indexing "   numIndexed   " files took "   (end - start)   " milliseconds");
      }
   
      // open an index and start file directory traversal
      public static int index(File indexDir, File dataDir) throws IOException {
      if (!dataDir.exists() || !dataDir.isDirectory()) {
          throw new IOException(dataDir   " does not exist or is not a directory");
      }
      IndexWriter writer = new IndexWriter(indexDir, new StandardAnalyzer(), true);
      writer.setUseCompoundFile(false);
      indexDirectory(writer, dataDir);
      int numIndexed = writer.docCount();
      writer.optimize();
      writer.close();
      return numIndexed;
      }
   
      // recursive method that calls itself when it finds a directory
   
   
                  
      private static void indexDirectory(IndexWriter writer, File dir) throws IOException {
      File[] files = dir.listFiles();
      for (int i = 0; i < files.length; i) {
          File f = files;
          if (f.isDirectory()) {
            indexDirectory(writer, f);
          } else if (f.getName().endsWith(".txt")) {
            indexFile(writer, f);
          }
      }
      }
   
      // method to actually index file using Lucene
      private static void indexFile(IndexWriter writer, File f) throws IOException {
      if (f.isHidden() || !f.exists() || !f.canRead()) {
          return;
      }
      System.out.println("Indexing "   f.getCanonicalPath());
      Document doc = new Document();
      doc.add(Field.Text("contents", new FileReader(f)));
      doc.add(Field.Keyword("filename", f.getCanonicalPath()));
      writer.addDocument(doc);
      }
    }
    import java.io.File;
    import java.io.FileReader;
    import java.io.IOException;
    import java.util.Date;
    import org.apache.lucene.analysis.standard.StandardAnalyzer;
    import org.apache.lucene.document.Document;
    import org.apache.lucene.document.Field;
    import org.apache.lucene.index.IndexWriter;
   
    public class Indexer {
      public static void main(String[] args) throws Exception {
      if (args.length != 2) {
          throw new Exception("Usage: java "   Indexer.class.getName()   " <index dir> <data dir>");
      }
      File indexDir = new File(args);
      File dataDir = new File(args);
      long start = new Date().getTime();
      int numIndexed = index(indexDir, dataDir);
      long end = new Date().getTime();
      System.out.println("Indexing "   numIndexed   " files took "   (end - start)   " milliseconds");
      }
   
      // open an index and start file directory traversal
      public static int index(File indexDir, File dataDir) throws IOException {
      if (!dataDir.exists() || !dataDir.isDirectory()) {
          throw new IOException(dataDir   " does not exist or is not a directory");
      }
      IndexWriter writer = new IndexWriter(indexDir, new StandardAnalyzer(), true);
      writer.setUseCompoundFile(false);
      indexDirectory(writer, dataDir);
      int numIndexed = writer.docCount();
      writer.optimize();
      writer.close();
      return numIndexed;
      }
   
      // recursive method that calls itself when it finds a directory
      private static void indexDirectory(IndexWriter writer, File dir) throws IOException {
      File[] files = dir.listFiles();
      for (int i = 0; i < files.length; i) {
          File f = files;
          if (f.isDirectory()) {
            indexDirectory(writer, f);
          } else if (f.getName().endsWith(".txt")) {
            indexFile(writer, f);
          }
      }
      }
   
   
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   // method to actually index file using Lucene
      private static void indexFile(IndexWriter writer, File f) throws IOException {
      if (f.isHidden() || !f.exists() || !f.canRead()) {
          return;
      }
      System.out.println("Indexing "   f.getCanonicalPath());
      Document doc = new Document();
      doc.add(Field.Text("contents", new FileReader(f)));
      doc.add(Field.Keyword("filename", f.getCanonicalPath()));
      writer.addDocument(doc);
      }
    }另一个是搜索:
    view plaincopy to clipboardprint?
    import java.io.File;
    import java.util.Date;
    import org.apache.lucene.analysis.standard.StandardAnalyzer;
    import org.apache.lucene.document.Document;
    import org.apache.lucene.queryParser.QueryParser;
    import org.apache.lucene.search.Hits;
    import org.apache.lucene.search.IndexSearcher;
    import org.apache.lucene.search.Query;
    import org.apache.lucene.store.Directory;
    import org.apache.lucene.store.FSDirectory;
    public class Searcher {
      public static void main(String[] args) throws Exception {
      if (args.length != 2) {
          throw new Exception("Usage: java "   Searcher.class.getName()   " <index dir> <auery>");
      }
      File indexDir = new File(args);
      String q = args;
      if (!indexDir.exists() || !indexDir.isDirectory()) {
          throw new Exception(indexDir   " does not exist or is not a directory.");
      }
      search(indexDir, q);
      }
      public static void search(File indexDir, String q) throws Exception {
      Directory fsDir = FSDirectory.getDirectory(indexDir, false);
      IndexSearcher is = new IndexSearcher(fsDir);
      Query query = QueryParser.parse(q, "contents", new StandardAnalyzer());
      long start = new Date().getTime();
      Hits hits = is.search(query);
      long end = new Date().getTime();
      System.err.println("Found "   hits.length()   " document(s) (in "   (end - start)   " milliseconds) that matched query ‘"
            q   "’:");
      for (int i = 0; i < hits.length(); i) {
          Document doc = hits.doc(i);
          System.out.println(doc.get("filename"));
      }
      }
    }
    import java.io.File;
    import java.util.Date;
    import org.apache.lucene.analysis.standard.StandardAnalyzer;
    import org.apache.lucene.document.Document;
    import org.apache.lucene.queryParser.QueryParser;
    import org.apache.lucene.search.Hits;
    import org.apache.lucene.search.IndexSearcher;
    import org.apache.lucene.search.Query;
    import org.apache.lucene.store.Directory;
    import org.apache.lucene.store.FSDirectory;
    public class Searcher {
   
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   public static void main(String[] args) throws Exception {
      if (args.length != 2) {
          throw new Exception("Usage: java "   Searcher.class.getName()   " <index dir> <auery>");
      }
      File indexDir = new File(args);
      String q = args;
      if (!indexDir.exists() || !indexDir.isDirectory()) {
          throw new Exception(indexDir   " does not exist or is not a directory.");
      }
      search(indexDir, q);
      }
      public static void search(File indexDir, String q) throws Exception {
      Directory fsDir = FSDirectory.getDirectory(indexDir, false);
      IndexSearcher is = new IndexSearcher(fsDir);
      Query query = QueryParser.parse(q, "contents", new StandardAnalyzer());
      long start = new Date().getTime();
      Hits hits = is.search(query);
      long end = new Date().getTime();
      System.err.println("Found "   hits.length()   " document(s) (in "   (end - start)   " milliseconds) that matched query ‘"
            q   "’:");
      for (int i = 0; i < hits.length(); i) {
          Document doc = hits.doc(i);
          System.out.println(doc.get("filename"));
      }
      }
    }
   ok,这样就简单实现了,在搜索目录下所有txt,找出包括某一个字符串的txt文件名的功能。    上一页
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