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1 /*
2
3  ============================================================================
4                    The Apache Software License, Version 1.1
5  ============================================================================
6  
7  Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
8  
9  Redistribution and use in source and binary forms, with or without modifica-
10  tion, are permitted provided that the following conditions are met:
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12  1. Redistributions of source code must retain the above copyright notice,
13     this list of conditions and the following disclaimer.
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15  2. Redistributions in binary form must reproduce the above copyright notice,
16     this list of conditions and the following disclaimer in the documentation
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20     include the following acknowledgment: "This product includes software
21     developed by the Apache Software Foundation (http://www.apache.org/)."
22     Alternately, this acknowledgment may appear in the software itself, if
23     and wherever such third-party acknowledgments normally appear.
24  
25  4. The names "Jakarta", "Avalon", "Excalibur" and "Apache Software Foundation"
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45  This software consists of voluntary contributions made by many individuals
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48
49 */
50
51 package org.apache.excalibur.configuration;
52
53 import java.util.ArrayList JavaDoc;
54
55 import org.apache.avalon.framework.configuration.Configuration;
56 import org.apache.avalon.framework.configuration.DefaultConfiguration;
57
58 /**
59  * General utility supporting static operations for generating string
60  * representations of a configuration suitable for debugging.
61  * @author Stephen McConnell <mcconnell@osm.net>
62  * @author <a HREF="mailto:proyal@apache.org">Peter Royal</a>
63  */
64 public class ConfigurationUtil
65 {
66     /**
67      * Returns a simple string representation of the the supplied configuration.
68      * @param config a configuration
69      * @return a simplified text representation of a configuration suitable
70      * for debugging
71      */
72     public static String JavaDoc list( Configuration config )
73     {
74         final StringBuffer JavaDoc buffer = new StringBuffer JavaDoc();
75         list( buffer, " ", config );
76         buffer.append( "\n" );
77         return buffer.toString();
78     }
79
80     /**
81      * populates a string buffer with an XML representation of a supplied configuration.
82      * @param buffer the string buffer
83      * @param lead padding offset
84      * @param config a configuration
85      * @return a simplified text representation of a configuration suitable
86      * for debugging
87      */
88     public static void list( StringBuffer JavaDoc buffer, String JavaDoc lead, Configuration config )
89     {
90
91         buffer.append( "\n" + lead + "<" + config.getName() );
92         String JavaDoc[] names = config.getAttributeNames();
93         if( names.length > 0 )
94         {
95             for( int i = 0; i < names.length; i++ )
96             {
97                 buffer.append( " "
98                                + names[ i ] + "=\""
99                                + config.getAttribute( names[ i ], "???" ) + "\"" );
100             }
101         }
102         Configuration[] children = config.getChildren();
103         if( children.length > 0 )
104         {
105             buffer.append( ">" );
106             for( int j = 0; j < children.length; j++ )
107             {
108                 list( buffer, lead + " ", children[ j ] );
109             }
110             buffer.append( "\n" + lead + "</" + config.getName() + ">" );
111         }
112         else
113         {
114             try
115             {
116                 String JavaDoc value = config.getValue();
117                 if( !value.equals( "" ) )
118                 {
119                     buffer.append( ">" + value + "</" + config.getName() + ">" );
120                 }
121                 else
122                 {
123                     buffer.append( "/>" );
124                 }
125             }
126             catch( Throwable JavaDoc ce )
127             {
128                 buffer.append( "/>" );
129             }
130         }
131     }
132
133     /**
134      * Return all occurance of a configuration child containing the supplied attribute name.
135      * @param config the configuration
136      * @param element the name of child elements to select from the configuration
137      * @param attribute the attribute name to filter (null will match any attribute name)
138      * @return an array of configuration instances matching the query
139      */
140     public static Configuration[] match( final Configuration config,
141                                          final String JavaDoc element,
142                                          final String JavaDoc attribute )
143     {
144         return match( config, element, attribute, null );
145     }
146
147     /**
148      * Return occurance of a configuration child containing the supplied attribute name and value.
149      * @param config the configuration
150      * @param element the name of child elements to select from the configuration
151      * @param attribute the attribute name to filter (null will match any attribute name )
152      * @param value the attribute value to match (null will match any attribute value)
153      * @return an array of configuration instances matching the query
154      */
155     public static Configuration[] match( final Configuration config,
156                                          final String JavaDoc element,
157                                          final String JavaDoc attribute,
158                                          final String JavaDoc value )
159     {
160         final ArrayList JavaDoc list = new ArrayList JavaDoc();
161         final Configuration[] children = config.getChildren( element );
162
163         for( int i = 0; i < children.length; i++ )
164         {
165             if( null == attribute )
166             {
167                 list.add( children[ i ] );
168             }
169             else
170             {
171                 String JavaDoc v = children[ i ].getAttribute( attribute, null );
172
173                 if( v != null )
174                 {
175                     if( ( value == null ) || v.equals( value ) )
176                     {
177                         // it's a match
178 list.add( children[ i ] );
179                     }
180                 }
181             }
182         }
183
184         return (Configuration[])list.toArray( new Configuration[ list.size() ] );
185     }
186
187     /**
188      * Return the first occurance of a configuration child containing the supplied attribute name
189      * and value or create a new empty configuration if no match found.
190      * @param config the configuration
191      * @param element the name of child elements to select from the configuration
192      * @param attribute the attribute name to filter
193      * @param value the attribute value to match (null will match any attribute value)
194      * @return a configuration instances matching the query or empty configuration
195      */
196     public static Configuration matchFirstOccurance(
197         Configuration config, String JavaDoc element, String JavaDoc attribute, String JavaDoc value )
198     {
199         return matchFirstOccurance( config, element, attribute, value, true );
200     }
201
202     /**
203      * Return the first occurance of a configuration child containing the supplied attribute
204      * name and value. If the supplied creation policy if TRUE and no match is found, an
205      * empty configuration instance is returned, otherwise a null will returned.
206      * @param config the configuration
207      * @param element the name of child elements to select from the configuration
208      * @param attribute the attribute name to filter
209      * @param value the attribute value to match (null will match any attribute value)
210      * @param create the creation policy if no match
211      * @return a configuration instances matching the query
212      */
213     public static Configuration matchFirstOccurance(
214         Configuration config, String JavaDoc element, String JavaDoc attribute, String JavaDoc value, boolean create )
215     {
216         Configuration[] children = config.getChildren( element );
217         for( int i = 0; i < children.length; i++ )
218         {
219             String JavaDoc v = children[ i ].getAttribute( attribute, null );
220             if( v != null )
221             {
222                 if( ( value == null ) || v.equals( value ) )
223                 {
224                     // it's a match
225 return children[ i ];
226                 }
227             }
228         }
229
230         return create ? new DefaultConfiguration( element, null ) : null;
231     }
232
233     /**
234      * Test to see if two Configuration's can be considered the same. Name, value, attributes
235      * and children are test. The <b>order</b> of children is not taken into consideration
236      * for equality.
237      *
238      * @param c1 Configuration to test
239      * @param c2 Configuration to test
240      * @return true if the configurations can be considered equals
241      */
242     public static boolean equals( final Configuration c1, final Configuration c2 )
243     {
244         return org.apache.avalon.framework.configuration.ConfigurationUtil.equals(c1, c2 );
245     }
246 }
247
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