KickJava   Java API By Example, From Geeks To Geeks.

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


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 org.apache.commons.beanutils.ConversionException;
22 import org.apache.commons.beanutils.Converter;
23
24 import java.net.URL JavaDoc;
25 import java.net.MalformedURLException JavaDoc;
26
27
28
29 /**
30  * <p>Standard {@link Converter} implementation that converts an incoming
31  * String into a <code>java.net.URL</code> object, optionally using a
32  * default value or throwing a {@link ConversionException} if a conversion
33  * error occurs.</p>
34  *
35  * @author Henri Yandell
36  * @version $Revision: 1.4 $ $Date: 2004/02/28 13:18:34 $
37  * @since 1.3
38  */
39
40 public final class URLConverter implements Converter {
41
42
43     // ----------------------------------------------------------- Constructors
44
45
46     /**
47      * Create a {@link Converter} that will throw a {@link ConversionException}
48      * if a conversion error occurs.
49      */
50     public URLConverter() {
51
52         this.defaultValue = null;
53         this.useDefault = false;
54
55     }
56
57
58     /**
59      * Create a {@link Converter} that will return the specified default value
60      * if a conversion error occurs.
61      *
62      * @param defaultValue The default value to be returned
63      */
64     public URLConverter(Object JavaDoc defaultValue) {
65
66         this.defaultValue = defaultValue;
67         this.useDefault = true;
68
69     }
70
71
72     // ----------------------------------------------------- Instance Variables
73
74
75     /**
76      * The default value specified to our Constructor, if any.
77      */
78     private Object JavaDoc defaultValue = null;
79
80
81     /**
82      * Should we return the default value on conversion errors?
83      */
84     private boolean useDefault = true;
85
86
87     // --------------------------------------------------------- Public Methods
88
89
90     /**
91      * Convert the specified input object into an output object of the
92      * specified type.
93      *
94      * @param type Data type to which this value should be converted
95      * @param value The input value to be converted
96      *
97      * @exception ConversionException if conversion cannot be performed
98      * successfully
99      */
100     public Object JavaDoc convert(Class JavaDoc type, Object JavaDoc value) {
101
102         if (value == null) {
103             if (useDefault) {
104                 return (defaultValue);
105             } else {
106                 throw new ConversionException("No value specified");
107             }
108         }
109
110         if (value instanceof URL JavaDoc) {
111             return (value);
112         }
113
114         try {
115             return new URL JavaDoc(value.toString());
116         } catch(MalformedURLException JavaDoc murle) {
117             if (useDefault) {
118                 return (defaultValue);
119             } else {
120                 throw new ConversionException(murle);
121             }
122         }
123
124     }
125
126
127 }
128
Popular Tags