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.mavibot.btree.serializer;
21
22
23 import java.lang.reflect.Array;
24 import java.lang.reflect.GenericArrayType;
25 import java.lang.reflect.ParameterizedType;
26 import java.lang.reflect.Type;
27 import java.util.Comparator;
28
29
30 /**
31 * An abstract ElementSerializer that implements comon methods
32 *
33 * @param <T> The type for the element to serialize and compare
34 *
35 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
36 */
37 public abstract class AbstractElementSerializer<T> implements ElementSerializer<T>
38 {
39 /** The associated comparator */
40 private final Comparator<T> comparator;
41
42 /** The type which is being serialized */
43 private Class<?> type;
44
45
46 /**
47 * Create a new instance of Serializer
48 */
49 public AbstractElementSerializer( Comparator<T> comparator )
50 {
51 this.comparator = comparator;
52
53 // We will extract the Type to use for values, using the comparator for that
54 Class<?> comparatorClass = comparator.getClass();
55 Type[] types = comparatorClass.getGenericInterfaces();
56
57 if ( types[0] instanceof Class )
58 {
59 type = ( Class<?> ) types[0];
60 }
61 else
62 {
63 Type[] argumentTypes = ( ( ParameterizedType ) types[0] ).getActualTypeArguments();
64
65 if ( ( argumentTypes != null ) && ( argumentTypes.length > 0 ) )
66 {
67 if ( argumentTypes[0] instanceof Class<?> )
68 {
69 type = ( Class<?> ) argumentTypes[0];
70 }
71 else if ( argumentTypes[0] instanceof GenericArrayType )
72 {
73 Class<?> clazz = ( Class<?> ) ( ( GenericArrayType ) argumentTypes[0] ).getGenericComponentType();
74
75 type = Array.newInstance( clazz, 0 ).getClass();
76 }
77 }
78 }
79 }
80
81
82 /**
83 * {@inheritDoc}
84 */
85 public int compare( T type1, T type2 )
86 {
87 return comparator.compare( type1, type2 );
88 }
89
90
91 /**
92 * {@inheritDoc}
93 */
94 @Override
95 public Comparator<T> getComparator()
96 {
97 return comparator;
98 }
99
100
101 /**
102 * {@inheritDoc}
103 */
104 @Override
105 public Class<?> getType()
106 {
107 return type;
108 }
109 }