1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.directory.api.ldap.model.schema.comparators;
21
22
23 import org.apache.directory.api.ldap.model.schema.LdapComparator;
24 import org.apache.directory.api.util.Strings;
25 import org.slf4j.Logger;
26 import org.slf4j.LoggerFactory;
27
28
29 /**
30 * <p>
31 * A comparator for Words/KeyWords. RFC 4517 par. 4.2.21 (KeywordMatch) and par.
32 * 4.2.32 is pretty vague about the definition of what is a word or a keyword
33 * ("...The precise definition of a word is implementation specific...)
34 * ("...The identification of keywords in the attribute value and the exactness
35 * of the match are both implementation specific...).
36 * <p>
37 * We will simply check that the assertion is present in the value at some place,
38 * after having deep trimmed the word.
39 * <p>
40 * For instance, the word " World " will be found in the value "Hello world!".
41 * <p>
42 * A word is defined by the following regexp : "(^|[^A-Za-z0-9])([A-Za-z0-9])*([^A-Za-z0-9]|$)".
43 * Anything that is not matched by this regexp will not be considered as a word.
44 *
45 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
46 */
47 public class WordComparator extends LdapComparator<String>
48 {
49 /** The serial version UID */
50 private static final long serialVersionUID = 2L;
51
52 /** A logger for this class */
53 private static final Logger LOG = LoggerFactory.getLogger( WordComparator.class );
54
55
56 /**
57 * The StringComparator constructor. Its OID is the StringMatch matching
58 * rule OID.
59 *
60 * @param oid The Comparator's OID
61 */
62 public WordComparator( String oid )
63 {
64 super( oid );
65 }
66
67
68 /**
69 * {@inheritDoc}
70 */
71 public int compare( String value, String assertion )
72 {
73 LOG.debug( "comparing String objects '{}' with '{}'", value, assertion );
74
75 if ( value == assertion )
76 {
77 return 0;
78 }
79
80 // -------------------------------------------------------------------
81 // Handle some basis cases
82 // -------------------------------------------------------------------
83 if ( ( value == null ) || ( assertion == null ) )
84 {
85 return ( assertion == null ) ? 1 : -1;
86 }
87
88 // Now, trim the assertion and find it in the value
89 String trimmedAssertion = Strings.trim( assertion );
90 int pos = value.indexOf( trimmedAssertion );
91
92 if ( pos != -1 )
93 {
94 int assertionLength = trimmedAssertion.length();
95
96 // Check that we are not in a middle of some text
97 if ( assertionLength == value.length() )
98 {
99 return 0;
100 }
101
102 if ( pos == 0 )
103 {
104 char after = value.charAt( assertionLength );
105
106 if ( !Character.isLetterOrDigit( after ) )
107 {
108 return 0;
109 }
110 else
111 {
112 return -1;
113 }
114 }
115
116 if ( pos + assertionLength == value.length() )
117 {
118 char before = value.charAt( value.length() - assertionLength - 1 );
119
120 if ( !Character.isLetterOrDigit( before ) )
121 {
122 return 0;
123 }
124 else
125 {
126 return -1;
127 }
128 }
129
130 char before = value.charAt( value.length() - assertionLength );
131 char after = value.charAt( assertionLength );
132
133 if ( Character.isLetterOrDigit( after ) )
134 {
135 return -1;
136 }
137
138 if ( !Character.isLetterOrDigit( before ) )
139 {
140 return -1;
141 }
142
143 return 0;
144 }
145
146 return -1;
147 }
148 }