[21395] | 1 | /**********************************************************************
|
---|
| 2 | *
|
---|
| 3 | * JdbDel.java --
|
---|
| 4 | * A component of the Greenstone digital library software
|
---|
| 5 | * from the New Zealand Digital Library Project at the
|
---|
| 6 | * University of Waikato, New Zealand.
|
---|
| 7 | *
|
---|
| 8 | * Copyright (C) 1999 The New Zealand Digital Library Project
|
---|
| 9 | *
|
---|
| 10 | * This program is free software; you can redistribute it and/or modify
|
---|
| 11 | * it under the terms of the GNU General Public License as published by
|
---|
| 12 | * the Free Software Foundation; either version 2 of the License, or
|
---|
| 13 | * (at your option) any later version.
|
---|
| 14 | *
|
---|
| 15 | * This program is distributed in the hope that it will be useful,
|
---|
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
|
---|
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
---|
| 18 | * GNU General Public License for more details.
|
---|
| 19 | *
|
---|
| 20 | * You should have received a copy of the GNU General Public License
|
---|
| 21 | * along with this program; if not, write to the Free Software
|
---|
| 22 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
---|
| 23 | *
|
---|
| 24 | **********************************************************************/
|
---|
| 25 |
|
---|
| 26 | import java.io.BufferedInputStream;
|
---|
| 27 | import java.io.InputStream;
|
---|
| 28 |
|
---|
| 29 | import jdbm.RecordManager;
|
---|
| 30 | import jdbm.RecordManagerFactory;
|
---|
| 31 | import jdbm.helper.FastIterator;
|
---|
| 32 | import jdbm.htree.HTree;
|
---|
| 33 |
|
---|
| 34 | import java.io.IOException;
|
---|
| 35 | import java.util.Properties;
|
---|
| 36 |
|
---|
| 37 |
|
---|
| 38 | public class JdbDel
|
---|
| 39 | {
|
---|
| 40 | static String TNAME = "greenstone";
|
---|
| 41 |
|
---|
| 42 | RecordManager recman_;
|
---|
| 43 | HTree hashtable_;
|
---|
| 44 |
|
---|
| 45 | public JdbDel(String db_filename)
|
---|
| 46 | throws IOException
|
---|
| 47 | {
|
---|
| 48 | // create or open a record manager
|
---|
| 49 | Properties props = new Properties();
|
---|
| 50 | recman_ = RecordManagerFactory.createRecordManager(db_filename, props);
|
---|
| 51 |
|
---|
| 52 | // load existing table (if exists) otherwise report error
|
---|
| 53 | long recid = recman_.getNamedObject(TNAME);
|
---|
| 54 |
|
---|
| 55 | if (recid != 0) {
|
---|
| 56 | System.out.println("Loading existing database table '" + TNAME +"' ...");
|
---|
| 57 | hashtable_ = HTree.load(recman_, recid);
|
---|
| 58 | }
|
---|
| 59 | else {
|
---|
| 60 | recman_.close();
|
---|
| 61 | System.out.println("No database table '" + TNAME +"' to delete key from.");
|
---|
| 62 | System.exit(-1);
|
---|
| 63 | }
|
---|
| 64 | }
|
---|
| 65 |
|
---|
| 66 |
|
---|
| 67 | public void del(String key)
|
---|
| 68 | throws IOException
|
---|
| 69 | {
|
---|
| 70 | hashtable_.remove(key);
|
---|
| 71 | recman_.close();
|
---|
| 72 | }
|
---|
| 73 |
|
---|
| 74 |
|
---|
| 75 | public static void print_usage()
|
---|
| 76 | {
|
---|
| 77 | System.err.println("Usage: java JdbDel database-name key");
|
---|
| 78 | System.exit(-1);
|
---|
| 79 | }
|
---|
| 80 |
|
---|
| 81 |
|
---|
| 82 | public static void main(String[] args)
|
---|
| 83 | {
|
---|
| 84 | int argc = args.length;
|
---|
| 85 |
|
---|
| 86 | // sanity check
|
---|
| 87 | if (argc!=2) {
|
---|
| 88 | print_usage();
|
---|
| 89 | }
|
---|
| 90 |
|
---|
| 91 | try {
|
---|
| 92 | String dbname = args[0];
|
---|
| 93 | JdbDel table = new JdbDel(dbname);
|
---|
| 94 |
|
---|
| 95 | String key = args[1];
|
---|
| 96 | table.del(key);
|
---|
| 97 | }
|
---|
| 98 |
|
---|
| 99 | catch (IOException e) {
|
---|
| 100 | e.printStackTrace();
|
---|
| 101 | }
|
---|
| 102 |
|
---|
| 103 | }
|
---|
| 104 |
|
---|
| 105 | }
|
---|
| 106 |
|
---|
| 107 |
|
---|