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1
55
56 package org.apache.avalon.framework.component;
57
58 import org.apache.avalon.framework.service.ServiceSelector;
59 import org.apache.avalon.framework.service.ServiceException;
60
61
69 public class WrapperComponentSelector
70 implements ComponentSelector
71 {
72
75 private final ServiceSelector m_selector;
76
77
80 private final String  m_key;
81
82
88 public WrapperComponentSelector( final String key,
89 final ServiceSelector selector )
90 {
91 if( null == key )
92 {
93 throw new NullPointerException ( "key" );
94 }
95 if( null == selector )
96 {
97 throw new NullPointerException ( "selector" );
98 }
99
100 m_key = key + "/";
101 m_selector = selector;
102 }
103
104
111 public Component select( final Object policy )
112 throws ComponentException
113 {
114 try
115 {
116 final Object object = m_selector.select( policy );
117 if( object instanceof Component )
118 {
119 return (Component)object;
120 }
121 }
122 catch( final ServiceException se )
123 {
124 throw new ComponentException( m_key + policy, se.getMessage(), se );
125 }
126
127 final String message = "Role does not implement the Component "
128 + "interface and thus can not be accessed via ComponentSelector";
129 throw new ComponentException( m_key + policy, message );
130 }
131
132
138 public boolean hasComponent( final Object policy )
139 {
140 return m_selector.isSelectable( policy );
141 }
142
143
152 public void release( final Component object )
153 {
154 m_selector.release( object );
155 }
156
157
164 ServiceSelector getWrappedSelector()
165 {
166 return m_selector;
167 }
168 }
169 |
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