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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 }