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1
17
18 package org.apache.avalon.cornerstone.blocks.datasources;
19
20 import java.util.HashMap  ;
21 import java.util.Iterator ;
22 import java.util.Map ;
23
24 import org.apache.avalon.cornerstone.services.datasources.DataSourceSelector;
25
26 import org.apache.avalon.excalibur.datasource.DataSourceComponent;
27 import org.apache.avalon.framework.activity.Disposable;
28 import org.apache.avalon.framework.activity.Initializable;
29 import org.apache.avalon.framework.configuration.Configurable;
30 import org.apache.avalon.framework.configuration.Configuration;
31 import org.apache.avalon.framework.context.Context;
32 import org.apache.avalon.framework.context.ContextException;
33 import org.apache.avalon.framework.context.Contextualizable;
34 import org.apache.avalon.framework.logger.AbstractLogEnabled;
35 import org.apache.avalon.framework.logger.LogEnabled;
36 import org.apache.avalon.framework.service.ServiceException;
37
38
62 public class DefaultDataSourceSelector
63 extends AbstractLogEnabled
64 implements DataSourceSelector, Contextualizable, Configurable, Initializable, Disposable
65 {
66 private Configuration m_configuration;
67 private Map m_dataSources;
68 private String m_blockName;
69
70
71
76 public void contextualize( final Context context )
77 throws ContextException
78 {
79 try
80 {
81 m_blockName = (String ) context.get( "urn:avalon:name" );
82 }
83 catch( Throwable e )
84 {
85 try
87 {
88 m_blockName = (String )context.get( "block.name" );
89 }
90 catch( Throwable ee )
91 {
92 m_blockName = "DataSourceSelector/" + System.identityHashCode( this );
93 }
94 }
95 }
96
97
100 public void configure( final Configuration configuration )
101 {
102 m_configuration = configuration;
103 }
104
105 public void initialize()
106 throws Exception
107 {
108 m_dataSources = new HashMap ();
109
110 Configuration[] dataSourceConfs = getDataSourceConfig();
111
112 for( int i = 0; i < dataSourceConfs.length; i++ )
113 {
114 final Configuration dataSourceConf = dataSourceConfs[ i ];
115
116 final String name = dataSourceConf.getAttribute( "name" );
117 final String clazz = dataSourceConf.getAttribute( "class" );
118 final String driver = dataSourceConf.getChild( "driver", true ).getValue( "" );
119
120 final ClassLoader classLoader =
121 Thread.currentThread().getContextClassLoader();
122
123 DataSourceComponent component = null;
124 if( null == classLoader )
125 {
126 if( !"".equals( driver ) )
127 {
128 Class.forName( driver, true, Thread.currentThread().getContextClassLoader() );
129 }
130
131 component = (DataSourceComponent)Class.forName( clazz ).newInstance();
132 }
133 else
134 {
135 if( !"".equals( driver ) )
136 {
137 classLoader.loadClass( driver );
138 }
139
140 component = (DataSourceComponent)classLoader.loadClass( clazz ).newInstance();
141 }
142
143 if( component instanceof LogEnabled )
144 {
145 setupLogger( component, name );
146 }
147 component.configure( dataSourceConf );
148 m_dataSources.put( name, component );
149
150 if( getLogger().isInfoEnabled() )
151 {
152 getLogger().info( "DataSource " + name + " ready" );
153 }
154 }
155 }
156
157 private Configuration[] getDataSourceConfig()
158 {
159 final Configuration head =
160 m_configuration.getChild( "data-sources" );
161 if( 0 != head.getChildren().length )
162 {
163
164 final String message =
165 "WARNING: Child node <data-sources/> in " +
166 "configuration of component named " + m_blockName +
167 " has been deprecated. Please put <data-source/> elements" +
168 " in root configuration element";
169 getLogger().warn( message );
170 System.out.println( message );
171 return head.getChildren( "data-source" );
172 }
173 else
174 {
175 return m_configuration.getChildren( "data-source" );
176 }
177 }
178
179 public void dispose()
180 {
181 if( getLogger().isDebugEnabled() )
182 {
183 getLogger().debug( "disposal" );
184 }
185 final Iterator keys = m_dataSources.keySet().iterator();
186 while( keys.hasNext() )
187 {
188 final DataSourceComponent dsc =
189 (DataSourceComponent)m_dataSources.get( keys.next() );
190 if( dsc instanceof Disposable )
191 {
192 ( (Disposable)dsc ).dispose();
193 }
194 }
195 }
196
197 public boolean isSelectable( final Object hint )
198 {
199 return m_dataSources.containsKey( hint );
200 }
201
202 public Object select( final Object hint )
203 throws ServiceException
204 {
205 final Object component = m_dataSources.get( hint );
206
207 if( null == component )
208 {
209 throw new ServiceException( hint.toString(), "Unable to provide DataSourceComponent for " + hint );
210 }
211
212 return component;
213 }
214
215 public void release( final Object component )
216 {
217 }
219 }
220 |
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