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Java > Open Source Codes > org > apache > log > filter > AbstractFilterTarget


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55 package org.apache.log.filter;
56
57 import org.apache.log.FilterTarget;
58 import org.apache.log.LogEvent;
59 import org.apache.log.LogTarget;
60
61 /**
62  * Abstract implementation of FilterTarget.
63  * A concrete implementation has to implement filter method.
64  *
65  * @author <a HREF="mailto:dev@avalon.apache.org">Avalon Development Team</a>
66  * @author <a HREF="mailto:peter@apache.org">Peter Donald</a>
67  */
68 public abstract class AbstractFilterTarget
69     implements FilterTarget, LogTarget
70 {
71     //Log targets in filter chain
72 private LogTarget m_targets[];
73
74     /**
75      * Add a new target to output chain.
76      *
77      * @param target the target
78      */
79     public void addTarget( final LogTarget target )
80     {
81         if( null == m_targets )
82         {
83             m_targets = new LogTarget[]{target};
84         }
85         else
86         {
87             final LogTarget oldTargets[] = m_targets;
88             m_targets = new LogTarget[ oldTargets.length + 1 ];
89             System.arraycopy( oldTargets, 0, m_targets, 0, oldTargets.length );
90             m_targets[ m_targets.length - 1 ] = target;
91         }
92     }
93
94     /**
95      * Filter the log event.
96      *
97      * @param event the event
98      * @return return true to discard event, false otherwise
99      */
100     protected abstract boolean filter( LogEvent event );
101
102     /**
103      * Process a log event
104      *
105      * @param event the log event
106      */
107     public void processEvent( final LogEvent event )
108     {
109         if( null == m_targets || filter( event ) )
110         {
111             return;
112         }
113         else
114         {
115             for( int i = 0; i < m_targets.length; i++ )
116             {
117                 m_targets[ i ].processEvent( event );
118             }
119         }
120     }
121 }
122
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