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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  package org.apache.commons.beanutils.converters;
    18
    19  /***
    20   * {@link org.apache.commons.beanutils.Converter}
    21   * implementation that converts an incoming
    22   * object into a <code>java.lang.String</code> object.
    23   * <p>
    24   * Note that ConvertUtils really is designed to do string->object conversions,
    25   * and offers very little support for object->string conversions. The
    26   * ConvertUtils/ConvertUtilsBean methods only select a converter to apply
    27   * based upon the target type being converted to, and generally assume that
    28   * the input is a string (by calling its toString method if needed).
    29   * <p>
    30   * This class is therefore just a dummy converter that converts its input
    31   * into a string by calling the input object's toString method and returning
    32   * that value.
    33   * <p>
    34   * It is possible to replace this converter with something that has a big
    35   * if/else statement that selects behaviour based on the real type of the
    36   * object being converted (or possibly has a map of converters, and looks
    37   * them up based on the class of the input object). However this is not part
    38   * of the existing ConvertUtils framework.
    39   *
    40   *
    41   * @author Craig R. McClanahan
    42   * @version $Revision: 555845 $ $Date: 2007-07-13 03:52:05 +0100 (Fri, 13 Jul 2007) $
    43   * @since 1.3
    44   */
    45  public final class StringConverter extends AbstractConverter {
    46
    47
    48      /***
    49       * Construct a <b>java.lang.String</b> <i>Converter</i> that throws
    50       * a <code>ConversionException</code> if an error occurs.
    51       */
    52      public StringConverter() {
    53          super(String.class);
    54      }
    55
    56      /***
    57       * Construct a <b>java.lang.String</b> <i>Converter</i> that returns
    58       * a default value if an error occurs.
    59       *
    60       * @param defaultValue The default value to be returned
    61       * if the value to be converted is missing or an error
    62       * occurs converting the value.
    63       */
    64      public StringConverter(Object defaultValue) {
    65          super(String.class, defaultValue);
    66      }
    67
    68      /***
    69       * Convert the specified input object into an output object of the
    70       * specified type.
    71       *
    72       * @param type Data type to which this value should be converted.
    73       * @param value The input value to be converted.
    74       * @return The converted value.
    75       * @throws Throwable if an error occurs converting to the specified type
    76       */
    77      protected Object convertToType(Class type, Object value) throws Throwable {
    78          return value.toString();
    79      }
    80
    81
    82  }