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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  
19  package org.apache.commons.beanutils.converters;
20  
21  
22  import java.util.List;
23  import org.apache.commons.beanutils.ConversionException;
24  
25  
26  /***
27   * Standard {@link org.apache.commons.beanutils.Converter} implementation that converts an incoming
28   * String into an array of String objects. On a conversion failure, returns
29   * a specified default value or throws a {@link ConversionException} depending
30   * on how this instance is constructed.
31   * <p>
32   * There is also some special handling where the input is of type int[].
33   * See method convert for more details.  
34   *
35   * @author Craig R. McClanahan
36   * @version $Revision: 556229 $ $Date: 2007-07-14 07:11:19 +0100 (Sat, 14 Jul 2007) $
37   * @since 1.4
38   * @deprecated Replaced by the new {@link ArrayConverter} implementation
39   */
40  
41  public final class StringArrayConverter extends AbstractArrayConverter {
42  
43  
44      // ----------------------------------------------------------- Constructors
45  
46  
47      /***
48       * Create a {@link org.apache.commons.beanutils.Converter} that will throw
49       * a {@link ConversionException} if a conversion error occurs.
50       */
51      public StringArrayConverter() {
52  
53          this.defaultValue = null;
54          this.useDefault = false;
55  
56      }
57  
58  
59      /***
60       * Create a {@link org.apache.commons.beanutils.Converter} that will return
61       * the specified default value if a conversion error occurs.
62       *
63       * @param defaultValue The default value to be returned
64       */
65      public StringArrayConverter(Object defaultValue) {
66  
67          this.defaultValue = defaultValue;
68          this.useDefault = true;
69  
70      }
71  
72  
73      // ------------------------------------------------------- Static Variables
74  
75  
76      /***
77       * <p>Model object for type comparisons.</p>
78       */
79      private static final String[] MODEL = new String[0];
80      
81      /***
82       * <p> Model object for int arrays.</p>
83       */
84      private static final int[] INT_MODEL = new int[0];
85  
86  
87  
88      // --------------------------------------------------------- Public Methods
89  
90  
91      /***
92       * Convert the specified input object into an output object of the
93       * specified type.
94       * <p>
95       * If the value is already of type String[] then it is simply returned
96       * unaltered.
97       * <p>
98       * If the value is of type int[], then a String[] is returned where each
99       * element in the string array is the result of calling Integer.toString
100      * on the corresponding element of the int array. This was added as a
101      * result of bugzilla request #18297 though there is not complete
102      * agreement that this feature should have been added. 
103      * <p>
104      * In all other cases, this method calls toString on the input object, then
105      * assumes the result is a comma-separated list of values. The values are 
106      * split apart into the individual items and returned as the elements of an
107      * array. See class AbstractArrayConverter for the exact input formats
108      * supported.
109      * 
110      * @param type is the data type to which this value should be converted.
111      * It is expected to be the class for type String[] (though this parameter
112      * is actually ignored by this method).
113      * 
114      * @param value is the input value to be converted. If null then the
115      * default value is returned or an exception thrown if no default value
116      * exists.
117      * @return the converted value
118      *
119      * @exception ConversionException if conversion cannot be performed
120      * successfully, or the input is null and there is no default value set
121      * for this object.
122      */
123     public Object convert(Class type, Object value) {
124 
125         // Deal with a null value
126         if (value == null) {
127             if (useDefault) {
128                 return (defaultValue);
129             } else {
130                 throw new ConversionException("No value specified");
131             }
132         }
133 
134         // Deal with the no-conversion-needed case
135         if (MODEL.getClass() == value.getClass()) {
136             return (value);
137         }
138 
139         // Deal with the input value as an int array
140         if (INT_MODEL.getClass() == value.getClass())
141         {
142             int[] values = (int[]) value;
143             String[] results = new String[values.length];
144             for (int i = 0; i < values.length; i++)
145             {
146                 results[i] = Integer.toString(values[i]);
147             }
148 
149             return (results);
150         }
151 
152         // Parse the input value as a String into elements
153         // and convert to the appropriate type
154         try {
155             List list = parseElements(value.toString());
156             String[] results = new String[list.size()];
157             for (int i = 0; i < results.length; i++) {
158                 results[i] = (String) list.get(i);
159             }
160             return (results);
161         } catch (Exception e) {
162             if (useDefault) {
163                 return (defaultValue);
164             } else {
165                 throw new ConversionException(value.toString(), e);
166             }
167         }
168     }
169 
170 }