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Java > Open Source Codes > org > apache > torque > Database


1 package org.apache.torque;
2
3 /*
4  * Licensed to the Apache Software Foundation (ASF) under one
5  * or more contributor license agreements. See the NOTICE file
6  * distributed with this work for additional information
7  * regarding copyright ownership. The ASF licenses this file
8  * to you under the Apache License, Version 2.0 (the
9  * "License"); you may not use this file except in compliance
10  * with the License. You may obtain a copy of the License at
11  *
12  * http://www.apache.org/licenses/LICENSE-2.0
13  *
14  * Unless required by applicable law or agreed to in writing,
15  * software distributed under the License is distributed on an
16  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17  * KIND, either express or implied. See the License for the
18  * specific language governing permissions and limitations
19  * under the License.
20  */
21
22 import org.apache.torque.adapter.DB;
23 import org.apache.torque.dsfactory.DataSourceFactory;
24 import org.apache.torque.map.DatabaseMap;
25 import org.apache.torque.oid.IDBroker;
26 import org.apache.torque.oid.IdGenerator;
27
28 /**
29  * Bundles all information about a database. This includes the database adapter,
30  * the database Map and the Data Source Factory.
31  */
32 public class Database
33 {
34     /**
35      * The name of the database. Must be the same as the key in Torque's
36      * databaseMap.
37      */
38     private String JavaDoc name;
39
40     /**
41      * The Database adapter which encapsulates database-specific peculiarities.
42      */
43     private DB adapter;
44
45     /**
46      * the Map of this database.
47      */
48     private DatabaseMap databaseMap;
49
50     /**
51      * The DataSourceFactory to optain connections to this database.
52      */
53     private DataSourceFactory dataSourceFactory;
54
55     /**
56      * Creates a new Database with the given name.
57      *
58      * @param aName the name of the database, not null.
59      */
60     Database(String JavaDoc aName)
61     {
62         this.name = aName;
63     }
64
65     /**
66      * returns the name of the database.
67      *
68      * @return the name of the database. May be null.
69      */
70     public String JavaDoc getName()
71     {
72         return name;
73     }
74
75     /**
76      * Returns the adapther to this database.
77      *
78      * @return the adapter to this database, or null if no adapter is set.
79      */
80     public DB getAdapter()
81     {
82         return adapter;
83     }
84
85     /**
86      * Sets the adapter for this database.
87      *
88      * @param anAdapter The adapter for this database, or null to remove the
89      * current adapter from this database.
90      */
91     public void setAdapter(DB anAdapter)
92     {
93         this.adapter = anAdapter;
94     }
95
96     /**
97      * Returns the database map for this database.
98      * If the database map does not exist yet, it is created by this method.
99      */
100     public synchronized DatabaseMap getDatabaseMap()
101     {
102         if (databaseMap == null)
103         {
104             databaseMap = new DatabaseMap(name);
105         }
106         return databaseMap;
107     }
108
109     /**
110      * Returns the DataSourceFactory for this database.
111      * The DataSourceFactory is responsible to create connections
112      * to this database.
113      *
114      * @return the DataSourceFactory for this database, or null if no
115      * DataSourceFactory exists for this database.
116      */
117     public DataSourceFactory getDataSourceFactory()
118     {
119         return dataSourceFactory;
120     }
121
122     /**
123      * Sets the DataSourceFactory for this database.
124      * The DataSourceFactory is responsible to create connections
125      * to this database.
126      *
127      * @param aDataSourceFactory The new DataSorceFactory for this database,
128      * or null to remove the current DataSourceFactory.
129      */
130     public void setDataSourceFactory(DataSourceFactory aDataSourceFactory)
131     {
132         this.dataSourceFactory = aDataSourceFactory;
133     }
134
135     /**
136      * Get the IDBroker for this database.
137      *
138      * @return The IDBroker for this database, or null if no IdBroker has
139      * been started for this database.
140      */
141     public IDBroker getIDBroker()
142     {
143         if (databaseMap == null)
144         {
145             return null;
146         }
147         return databaseMap.getIDBroker();
148     }
149
150     /**
151      * Creates the IDBroker for this DatabaseMap and starts it for the
152      * given database.
153      * The information about the IdTable is stored in the databaseMap.
154      * If an IDBroker already exists for the DatabaseMap, the method
155      * does nothing.
156      *
157      * @return true if a new IDBroker was created, false otherwise.
158      */
159     public synchronized boolean startIDBroker()
160     {
161         DatabaseMap dbMap = getDatabaseMap();
162         if (dbMap.getIDBroker() != null)
163         {
164             return false;
165         }
166         return dbMap.startIdBroker();
167     }
168
169     /**
170      * Returns the IdGenerator of the given type for this Database.
171      * @param type The type (i.e.name) of the IdGenerator
172      * @return The IdGenerator of the requested type, or null if no IdGenerator
173      * exists for the requested type.
174      */
175     public IdGenerator getIdGenerator(String JavaDoc type)
176     {
177         if (databaseMap == null)
178         {
179             return null;
180         }
181         return databaseMap.getIdGenerator(type);
182     }
183
184     /**
185      * Adds an IdGenerator to the database.
186      * @param type The type of the IdGenerator
187      * @param idGen The new IdGenerator for the type, or null
188      * to remove the IdGenerator of the given type.
189      */
190     public void addIdGenerator(String JavaDoc type, IdGenerator idGen)
191     {
192         getDatabaseMap().addIdGenerator(type, idGen);
193     }
194
195     /**
196      * Returns the database schema for this Database.
197      * @return the database schema for this database, or null if no schema
198      * has been set.
199      */
200     public String JavaDoc getSchema()
201     {
202         DataSourceFactory dsf = getDataSourceFactory();
203         if (dsf == null)
204         {
205             return null;
206         }
207         return dsf.getSchema();
208     }
209
210     /**
211      * Sets the schema for this database.
212      * @param schema the name of the database schema to set, or null to remove
213      * the current schema.
214      * @throws NullPointerException if no DatasourceFactory exists for this
215      * database.
216      */
217     public void setSchema(String JavaDoc schema)
218     {
219         getDataSourceFactory().setSchema(schema);
220     }
221 }
222
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