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.filter;
21
22
23 import org.apache.directory.api.i18n.I18n;
24
25
26 /**
27 * Node used for the application of arbitrary predicates on return candidates.
28 * Applies dynamic and programatic criteria for the selection of candidates for
29 * return. Nodes of this type may be introduced into the filter expression to
30 * provided the opportunity to constrain the search further without altering the
31 * search algorithm.
32 *
33 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
34 */
35 public abstract class AssertionNode extends AbstractExprNode
36 {
37 /** The assertion or predicate to apply */
38 private final Assertion assertion;
39
40 /** Description of assertion for polish printouts */
41 private final String desc;
42
43
44 // ------------------------------------------------------------------------
45 // C O N S T R U C T O R S
46 // ------------------------------------------------------------------------
47
48 /**
49 * Creates an AssertionNode using an arbitrary candidate assertion.
50 *
51 * @param assertion the arbitrary selection logic.
52 */
53 public AssertionNode( Assertion assertion )
54 {
55 this( assertion, "ASSERTION" );
56
57 isSchemaAware = true;
58 }
59
60
61 /**
62 * Creates an AssertionNode using an arbitrary candidate assertion with a
63 * descriptions used for filter AST walker dumps.
64 *
65 * @param assertion the arbitrary selection logic.
66 * @param desc the printout representation for filter prints.
67 */
68 public AssertionNode( Assertion assertion, String desc )
69 {
70 super( AssertionType.ASSERTION );
71 this.desc = desc;
72 this.assertion = assertion;
73
74 /*
75 * We never want this node to ever make it to the point of becoming a
76 * candidate for use in an enumeration so we set the scan count to the
77 * maximum value.
78 */
79 set( "count", Long.MAX_VALUE );
80 }
81
82
83 /**
84 * Gets the Assertion used by this assertion node.
85 *
86 * @return the assertion used by this node
87 */
88 public Assertion getAssertion()
89 {
90 return assertion;
91 }
92
93
94 // ------------------------------------------------------------------------
95 // A B S T R A C T M E T H O D I M P L E M E N T A T I O N S
96 // ------------------------------------------------------------------------
97
98 /**
99 * Always returns true since an AssertionNode has no children.
100 *
101 * @see ExprNode#isLeaf()
102 * @return true if the node is a leaf,false otherwise
103 */
104 @Override
105 public boolean isLeaf()
106 {
107 return true;
108 }
109
110
111 /**
112 * @see ExprNode#printRefinementToBuffer(StringBuilder)
113 */
114 @Override
115 public StringBuilder printRefinementToBuffer( StringBuilder buf )
116 {
117 throw new UnsupportedOperationException( I18n.err( I18n.ERR_04145 ) );
118 }
119
120
121 /**
122 * {@inheritDoc}
123 */
124 @Override
125 public boolean equals( Object obj )
126 {
127 if ( obj == this )
128 {
129 return true;
130 }
131
132 if ( ( obj == null ) || !( obj instanceof AssertionNode ) )
133 {
134 return false;
135 }
136 AssertionNode that = ( AssertionNode ) obj;
137 if ( assertion == null )
138 {
139 if ( that.assertion != null )
140 {
141 return false;
142 }
143 }
144 else
145 {
146 if ( !assertion.equals( that.assertion ) )
147 {
148 return false;
149 }
150 }
151 if ( desc == null )
152 {
153 if ( that.desc != null )
154 {
155 return false;
156 }
157 }
158 else
159 {
160 if ( !desc.equals( that.desc ) )
161 {
162 return false;
163 }
164 }
165 return super.equals( obj );
166 }
167
168
169 /**
170 * @see Object#hashCode()
171 * @return the instance's hash code
172 */
173 @Override
174 public int hashCode()
175 {
176 int h = 37;
177
178 h = h * 17 + super.hashCode();
179 h = h * 17 + ( assertion != null ? assertion.hashCode() : 0 );
180 h = h * 17 + ( desc != null ? desc.hashCode() : 0 );
181
182 return h;
183 }
184
185
186 /**
187 * @see ExprNode#accept(
188 *FilterVisitor)
189 */
190 @Override
191 public Object accept( FilterVisitor visitor )
192 {
193 return visitor.visit( this );
194 }
195
196
197 /**
198 * @see Object#toString
199 * @return A string representing the AndNode
200 */
201 @Override
202 public String toString()
203 {
204 StringBuilder buf = new StringBuilder();
205
206 buf.append( "(@" );
207 buf.append( desc );
208 buf.append( super.toString() );
209 buf.append( ')' );
210
211 return buf.toString();
212 }
213 }