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Java > Open Source Codes > org > apache > avalon > framework > service > WrapperServiceManager


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55 package org.apache.avalon.framework.service;
56
57 import org.apache.avalon.framework.component.Component;
58 import org.apache.avalon.framework.component.ComponentException;
59 import org.apache.avalon.framework.component.ComponentManager;
60 import org.apache.avalon.framework.component.ComponentSelector;
61
62 /**
63  * This is a {@link ServiceManager} implementation that can wrap around a legacy
64  * {@link ComponentManager} object effectively adapting a {@link ComponentManager}
65  * interface to a {@link ServiceManager} interface.
66  *
67  * @author <a HREF="mailto:dev@avalon.apache.org">Avalon Development Team</a>
68  * @version CVS $Revision: 1.7 $ $Date: 2003/02/10 07:19:18 $
69  */
70 public class WrapperServiceManager
71     implements ServiceManager
72 {
73     /**
74      * The component manager thaty this class wraps.
75      */
76     private final ComponentManager m_componentManager;
77
78     /**
79      * This constructor is a constructor for a WrapperServiceManager.
80      *
81      * @param componentManager the ComponentManager instance that is being wrapped
82      */
83     public WrapperServiceManager( final ComponentManager componentManager )
84     {
85         if( null == componentManager )
86         {
87             throw new NullPointerException JavaDoc( "componentManager" );
88         }
89
90         m_componentManager = componentManager;
91     }
92
93     /**
94      * Retrieve a service using specified key.
95      *
96      * @param key the key to use to lookup component
97      * @return the matching service
98      * @throws ServiceException if unable to provide the service
99      * @see ServiceManager#lookup
100      */
101     public Object JavaDoc lookup( final String JavaDoc key )
102         throws ServiceException
103     {
104         try
105         {
106             final Object JavaDoc service = m_componentManager.lookup( key );
107             if( service instanceof ComponentSelector )
108             {
109                 return new WrapperServiceSelector( key, (ComponentSelector)service );
110             }
111             else
112             {
113                 return service;
114             }
115         }
116         catch( final ComponentException ce )
117         {
118             throw new ServiceException( key, ce.getMessage(), ce );
119         }
120     }
121
122     /**
123      * Return true if the component is available in ServiceManager.
124      *
125      * @param key the lookup
126      * @return true if the component is available in ServiceManager
127      */
128     public boolean hasService( final String JavaDoc key )
129     {
130         return m_componentManager.hasComponent( key );
131     }
132
133     /**
134      * Release the service back to the ServiceManager.
135      *
136      * @param service the service
137      */
138     public void release( final Object JavaDoc service )
139     {
140         if ( service instanceof WrapperServiceSelector )
141         {
142             m_componentManager.
143                 release( ((WrapperServiceSelector)service).getWrappedSelector() );
144         }
145         else
146         {
147             m_componentManager.release( (Component)service );
148         }
149     }
150 }
151
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