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1   /*
2    * $Source$
3    * $Revision$
4    *
5    * Copyright (C) 2000 Chris Kimpton
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   *     Chris Kimpton (kimtoc@techie.com)
42   *
43   */
44  package org.melati.poem.odmg;
45  
46  import java.util.Map;
47  import java.util.HashMap;
48  
49  import org.melati.LogicalDatabase;
50  import org.melati.util.DatabaseInitException;
51  
52  /** POEM implementation of the ODMG Database API. **/
53  final class Database implements org.odmg.Database {
54  
55    /** Hide this from general use. **/
56    private Database() {}
57  
58    /** Provide a package factory method 
59        so we could return a different type if needed. **/
60    static Database getNewDatabase() { 
61      return new Database(); 
62    }
63  
64    private org.melati.poem.Database _poemDB = null;
65    private String _logicalDB = null;
66  
67    org.melati.poem.Database getPoemDatabase() 
68      throws org.odmg.ODMGRuntimeException { 
69      if (_poemDB == null) throw new org.odmg.DatabaseClosedException(
70            "org.melati.poem.odmg.Database::getPoemDatabase - POEM DB not set");
71      return _poemDB; 
72    }
73  
74   /** Opens a connection to the db
75    * @param openParameters the Poem logical db name
76    */
77    public void open(String openParameters, int openType) 
78      throws org.odmg.ODMGException {
79      _logicalDB = openParameters;
80      try {
81        _poemDB = LogicalDatabase.getDatabase(_logicalDB);
82        _cachedTables = new HashMap<String,PoemTableAsDCollection<?>>();
83      } catch (DatabaseInitException err) {
84        err.printStackTrace();
85        throw new org.odmg.ODMGException(err.getMessage());
86      }
87    }
88  
89    public void close() { 
90      _poemDB.disconnect();
91      _poemDB = null;
92      _cachedTables = null;
93      ODMGFactory.resetDb();
94    }
95  
96    private Map<String,PoemTableAsDCollection<?>> _cachedTables = null;
97  
98   /** 
99    * Retrieves a collection wrapper for the selected table.
100   *
101   * @param objectIdentifier the name of the table for which a collection 
102   *                         is required
103   **/
104   @SuppressWarnings({ "unchecked", "rawtypes" })
105   public Object lookup(String objectIdentifier) 
106     throws org.odmg.ObjectNameNotFoundException { 
107     if (_poemDB == null) throw new org.odmg.DatabaseClosedException();
108     PoemTableAsDCollection<?> theObject = _cachedTables.get(objectIdentifier);
109     if (theObject == null) {
110       theObject = new PoemTableAsDCollection(_poemDB.
111                                                getTable(objectIdentifier));
112       _cachedTables.put(objectIdentifier,theObject);
113     }
114     return theObject;
115   }
116 
117   /** Not supported with the Poem / ODMG wrapper **/
118   public void makePersistent(Object objectToBePersistent) { 
119     throw new org.odmg.NotImplementedException(); 
120   }
121   /** Not supported with the Poem / ODMG wrapper **/
122   public void deletePersistent(Object persistedObject) { 
123     throw new org.odmg.NotImplementedException(); 
124   }
125   /** Not supported with the Poem / ODMG wrapper **/
126   public void bind(Object objectToBePersistent, String objectIdentifier) { 
127     throw new org.odmg.NotImplementedException(); 
128   }
129   /** Not supported with the Poem / ODMG wrapper **/
130   public void unbind(String objectIdentifier) { 
131     throw new org.odmg.NotImplementedException(); 
132   }
133    
134 }
135