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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.util.List;
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 an array of String.  On a conversion failure, returns
29   * a specified default value or throws a {@link ConversionException} depending
30   * on how this instance is constructed.</p>
31   *
32   * @author Craig R. McClanahan
33   * @version $Revision: 1.7 $ $Date: 2004/02/28 13:18:34 $
34   * @since 1.4
35   */
36  
37  public final class StringArrayConverter extends AbstractArrayConverter {
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 StringArrayConverter() {
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 StringArrayConverter(Object defaultValue) {
62  
63          this.defaultValue = defaultValue;
64          this.useDefault = true;
65  
66      }
67  
68  
69      // ------------------------------------------------------- Static Variables
70  
71  
72      /**
73       * <p>Model object for type comparisons.</p>
74       */
75      private static String model[] = new String[0];
76      
77      /**
78       * <p> Model object for int arrays.</p>
79       */
80      private static int ints[] = new int[0];
81  
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 convert(Class type, Object value) {
98  
99          // Deal with a null value
100         if (value == null) {
101             if (useDefault) {
102                 return (defaultValue);
103             } else {
104                 throw new ConversionException("No value specified");
105             }
106         }
107 
108         // Deal with the no-conversion-needed case
109         if (model.getClass() == value.getClass()) {
110             return (value);
111         }
112 
113         // Deal with the input value as an int array
114         if (ints.getClass() == value.getClass())
115         {
116             int[] values = (int[]) value;
117             String[] results = new String[values.length];
118             for (int i = 0; i < values.length; i++)
119             {
120                 results[i] = Integer.toString(values[i]);
121             }
122 
123             return (results);
124         }
125 
126         // Parse the input value as a String into elements
127         // and convert to the appropriate type
128         try {
129             List list = parseElements(value.toString());
130             String results[] = new String[list.size()];
131             for (int i = 0; i < results.length; i++) {
132                 results[i] = (String) list.get(i);
133             }
134             return (results);
135         } catch (Exception e) {
136             if (useDefault) {
137                 return (defaultValue);
138             } else {
139                 throw new ConversionException(value.toString(), e);
140             }
141         }
142 
143     }
144 
145 
146 }