1   package org.apache.lucene.demo;
    2   
    3   /**
    4    * Licensed to the Apache Software Foundation (ASF) under one or more
    5    * contributor license agreements.  See the NOTICE file distributed with
    6    * this work for additional information regarding copyright ownership.
    7    * The ASF licenses this file to You under the Apache License, Version 2.0
    8    * (the "License"); you may not use this file except in compliance with
    9    * the License.  You may obtain a copy of the License at
   10    *
   11    *     http://www.apache.org/licenses/LICENSE-2.0
   12    *
   13    * Unless required by applicable law or agreed to in writing, software
   14    * distributed under the License is distributed on an "AS IS" BASIS,
   15    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   16    * See the License for the specific language governing permissions and
   17    * limitations under the License.
   18    */
   19   
   20   import java.io.File;
   21   
   22   import org.apache.lucene.store.Directory;
   23   import org.apache.lucene.store.FSDirectory;
   24   import org.apache.lucene.index.IndexReader;
   25   import org.apache.lucene.index.Term;
   26   //import org.apache.lucene.index.Term;
   27   
   28   
   29   /** Deletes documents from an index that do not contain a term. */
   30   public class DeleteFiles {
   31     
   32     private DeleteFiles() {}                         // singleton
   33   
   34     /** Deletes documents from an index that do not contain a term. */
   35     public static void main(String[] args) {
   36       String usage = "java org.apache.lucene.demo.DeleteFiles <unique_term>";
   37       if (args.length == 0) {
   38         System.err.println("Usage: " + usage);
   39         System.exit(1);
   40       }
   41       try {
   42         Directory directory = FSDirectory.open(new File("index"));
   43         IndexReader reader = IndexReader.open(directory, false); // we don't want read-only because we are about to delete
   44   
   45         Term term = new Term("path", args[0]);
   46         int deleted = reader.deleteDocuments(term);
   47   
   48         System.out.println("deleted " + deleted +
   49    			 " documents containing " + term);
   50   
   51         // one can also delete documents by their internal id:
   52         /*
   53         for (int i = 0; i < reader.maxDoc(); i++) {
   54           System.out.println("Deleting document with id " + i);
   55           reader.delete(i);
   56         }*/
   57   
   58         reader.close();
   59         directory.close();
   60   
   61       } catch (Exception e) {
   62         System.out.println(" caught a " + e.getClass() +
   63   			 "\n with message: " + e.getMessage());
   64       }
   65     }
   66   }