| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| DbmsFactory |
|
| 4.0;4 |
| 1 | /* | |
| 2 | * $Source$ | |
| 3 | * $Revision$ | |
| 4 | * | |
| 5 | * Copyright (C) 2000 David Warnock | |
| 6 | * | |
| 7 | * Part of Melati (http://melati.org), a framework for the rapid | |
| 8 | * development of clean, maintainable web applications. | |
| 9 | * | |
| 10 | * Melati is free software; Permission is granted to copy, distribute | |
| 11 | * and/or modify this software under the terms either: | |
| 12 | * | |
| 13 | * a) the GNU General Public License as published by the Free Software | |
| 14 | * Foundation; either version 2 of the License, or (at your option) | |
| 15 | * any later version, | |
| 16 | * | |
| 17 | * or | |
| 18 | * | |
| 19 | * b) any version of the Melati Software License, as published | |
| 20 | * at http://melati.org | |
| 21 | * | |
| 22 | * You should have received a copy of the GNU General Public License and | |
| 23 | * the Melati Software License along with this program; | |
| 24 | * if not, write to the Free Software Foundation, Inc., | |
| 25 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the | |
| 26 | * GNU General Public License and visit http://melati.org to obtain the | |
| 27 | * Melati Software License. | |
| 28 | * | |
| 29 | * Feel free to contact the Developers of Melati (http://melati.org), | |
| 30 | * if you would like to work out a different arrangement than the options | |
| 31 | * outlined here. It is our intention to allow Melati to be used by as | |
| 32 | * wide an audience as possible. | |
| 33 | * | |
| 34 | * This program is distributed in the hope that it will be useful, | |
| 35 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 36 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 37 | * GNU General Public License for more details. | |
| 38 | * | |
| 39 | * Contact details for copyright holder: | |
| 40 | * | |
| 41 | * David Warnock (david At sundayta.co.uk) | |
| 42 | * Sundayta Ltd | |
| 43 | * International House, | |
| 44 | * 174 Three Bridges Road, | |
| 45 | * Crawley, | |
| 46 | * West Sussex | |
| 47 | * RH10 1LE, UK | |
| 48 | * | |
| 49 | */ | |
| 50 | ||
| 51 | package org.melati.poem.dbms; | |
| 52 | ||
| 53 | import java.util.Hashtable; | |
| 54 | ||
| 55 | import org.melati.poem.AppBugPoemException; | |
| 56 | ||
| 57 | /** | |
| 58 | * A factory class to create Dbms objects. | |
| 59 | */ | |
| 60 | public final class DbmsFactory { | |
| 61 | ||
| 62 | 1 | private static final Hashtable<String, Dbms> dbmsObjects = new Hashtable<String, Dbms>(); |
| 63 | ||
| 64 | 0 | private DbmsFactory() { |
| 65 | 0 | } |
| 66 | ||
| 67 | /** | |
| 68 | * Return a Dbms object given its class name as a String. | |
| 69 | * | |
| 70 | * @param dbmsClass | |
| 71 | * the name of the dbms class | |
| 72 | * @return a cached or newly created Dmbs object | |
| 73 | */ | |
| 74 | public static Dbms getDbms(String dbmsClass) { | |
| 75 | 466 | synchronized (dbmsObjects) { |
| 76 | 466 | Dbms dbms = (Dbms)dbmsObjects.get(dbmsClass); |
| 77 | 466 | if (dbms != null) { |
| 78 | 452 | return dbms; |
| 79 | } | |
| 80 | ||
| 81 | try { | |
| 82 | 14 | Object dbmsObject = Class.forName(dbmsClass).newInstance(); |
| 83 | ||
| 84 | 13 | if (!(dbmsObject instanceof Dbms)) { |
| 85 | 1 | throw new ClassCastException("The .class=" + dbmsClass |
| 86 | 1 | + " entry named a class of type " + dbmsObject.getClass() |
| 87 | + ", " + "which is not an org.melati.poem.dbms.Dbms"); | |
| 88 | } | |
| 89 | 12 | dbms = (Dbms)dbmsObject; |
| 90 | 2 | } catch (Exception e) { |
| 91 | 2 | throw new AppBugPoemException("Problem instantiating class " |
| 92 | + dbmsClass, e); | |
| 93 | 12 | } |
| 94 | 12 | dbmsObjects.put(dbmsClass, dbms); |
| 95 | 12 | return dbms; |
| 96 | 2 | } |
| 97 | } | |
| 98 | } |