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.server.schema;
21
22
23 import java.io.Serializable;
24 import java.util.Comparator;
25
26 import javax.naming.NamingException;
27
28 import org.apache.directory.server.schema.registries.ComparatorRegistry;
29
30
31 /**
32 * A serializable wrapper around a Comparator which uses delayed initialization
33 * of the underlying wrapped comparator which is JIT resolved from a static
34 * global registry.
35 *
36 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
37 * @version $Rev: 610243 $
38 */
39 public class SerializableComparator<E> implements Comparator<E>, Serializable
40 {
41 private static final long serialVersionUID = 3257566226288162870L;
42
43 /** the system global Comparator registry */
44 private static ComparatorRegistry registry;
45 /** the OID of the matchingRule for this comparator */
46 private String matchingRuleOid;
47 /** the transient wrapped comparator */
48 private transient Comparator<E> wrapped;
49
50
51 // ------------------------------------------------------------------------
52 // S T A T I C M E T H O D S
53 // ------------------------------------------------------------------------
54
55 /**
56 * Sets the global Comparator registry for comparator lookups.
57 *
58 * @param registry the comparator registry to use for Comparator lookups
59 */
60 public static void setRegistry( ComparatorRegistry registry )
61 {
62 SerializableComparator.registry = registry;
63 }
64
65
66 // ------------------------------------------------------------------------
67 // C O N T R U C T O R S
68 // ------------------------------------------------------------------------
69
70
71 public SerializableComparator( String matchingRuleOid )
72 {
73 this.matchingRuleOid = matchingRuleOid;
74 }
75
76
77 // ------------------------------------------------------------------------
78 // C O M P A R A T O R I M P L E M E N T A T I O N S
79 // ------------------------------------------------------------------------
80
81 /**
82 * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
83 */
84 @SuppressWarnings("unchecked")
85 public int compare( E o1, E o2 )
86 {
87 if ( wrapped == null )
88 {
89 try
90 {
91 wrapped = registry.lookup( matchingRuleOid );
92 }
93 catch ( NamingException e )
94 {
95 throw new RuntimeException( "Matching rule not found: " + matchingRuleOid );
96 }
97 }
98
99 return wrapped.compare( o1, o2 );
100 }
101 }