H5W3
当前位置:H5W3 > 其他技术问题 > 正文

apache lucene的一个简单实例

    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[0]);

        File dataDir = new File(args[1]);

        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[i];

          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[0]);

        File dataDir = new File(args[1]);

        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[i];

          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);

      }

    }  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[0]);

        String q = args[1];

        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 {

 

     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[0]);

        String q = args[1];

        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。

本文地址:H5W3 » apache lucene的一个简单实例

评论 0

  • 昵称 (必填)
  • 邮箱 (必填)
  • 网址