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Java > Open Source Codes > org > apache > commons > beanutils > converters > BigIntegerConverter


1 /*
2  * Copyright 2001-2004 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16
17
18 package org.apache.commons.beanutils.converters;
19
20
21 import java.math.BigInteger JavaDoc;
22 import org.apache.commons.beanutils.ConversionException;
23 import org.apache.commons.beanutils.Converter;
24
25
26 /**
27  * <p>Standard {@link Converter} implementation that converts an incoming
28  * String into a <code>java.math.BigInteger</code> object, optionally using a
29  * default value or throwing a {@link ConversionException} if a conversion
30  * error occurs.</p>
31  *
32  * @author Craig R. McClanahan
33  * @version $Revision: 1.7 $ $Date: 2004/02/28 13:18:34 $
34  * @since 1.3
35  */
36
37 public final class BigIntegerConverter implements Converter {
38
39
40     // ----------------------------------------------------------- Constructors
41
42
43     /**
44      * Create a {@link Converter} that will throw a {@link ConversionException}
45      * if a conversion error occurs.
46      */
47     public BigIntegerConverter() {
48
49         this.defaultValue = null;
50         this.useDefault = false;
51
52     }
53
54
55     /**
56      * Create a {@link Converter} that will return the specified default value
57      * if a conversion error occurs.
58      *
59      * @param defaultValue The default value to be returned
60      */
61     public BigIntegerConverter(Object JavaDoc defaultValue) {
62
63         this.defaultValue = defaultValue;
64         this.useDefault = true;
65
66     }
67
68
69     // ----------------------------------------------------- Instance Variables
70
71
72     /**
73      * The default value specified to our Constructor, if any.
74      */
75     private Object JavaDoc defaultValue = null;
76
77
78     /**
79      * Should we return the default value on conversion errors?
80      */
81     private boolean useDefault = true;
82
83
84     // --------------------------------------------------------- Public Methods
85
86
87     /**
88      * Convert the specified input object into an output object of the
89      * specified type.
90      *
91      * @param type Data type to which this value should be converted
92      * @param value The input value to be converted
93      *
94      * @exception ConversionException if conversion cannot be performed
95      * successfully
96      */
97     public Object JavaDoc convert(Class JavaDoc type, Object JavaDoc value) {
98
99         if (value == null) {
100             if (useDefault) {
101                 return (defaultValue);
102             } else {
103                 throw new ConversionException("No value specified");
104             }
105         }
106
107         if (value instanceof BigInteger JavaDoc) {
108             return (value);
109         }
110
111         try {
112             return (new BigInteger JavaDoc(value.toString()));
113         } catch (Exception JavaDoc e) {
114             if (useDefault) {
115                 return (defaultValue);
116             } else {
117                 throw new ConversionException(e);
118             }
119         }
120
121     }
122
123
124 }
125
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