    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017
    018
    019    package org.apache.commons.beanutils.converters;
    020
    021
    022    import java.util.List;
    023    import org.apache.commons.beanutils.ConversionException;
    024
    025
    026    /**
    027     * Standard {@link org.apache.commons.beanutils.Converter} implementation that converts an incoming
    028     * String into an array of String objects. On a conversion failure, returns
    029     * a specified default value or throws a {@link ConversionException} depending
    030     * on how this instance is constructed.
    031     * <p>
    032     * There is also some special handling where the input is of type int[].
    033     * See method convert for more details.
    034     *
    035     * @author Craig R. McClanahan
    036     * @version $Revision: 556229 $ $Date: 2007-07-14 07:11:19 +0100 (Sat, 14 Jul 2007) $
    037     * @since 1.4
    038     * @deprecated Replaced by the new {@link ArrayConverter} implementation
    039     */
    040
    041    public final class StringArrayConverter extends AbstractArrayConverter {
    042
    043
    044        // ----------------------------------------------------------- Constructors
    045
    046
    047        /**
    048         * Create a {@link org.apache.commons.beanutils.Converter} that will throw
    049         * a {@link ConversionException} if a conversion error occurs.
    050         */
    051        public StringArrayConverter() {
    052
    053            this.defaultValue = null;
    054            this.useDefault = false;
    055
    056        }
    057
    058
    059        /**
    060         * Create a {@link org.apache.commons.beanutils.Converter} that will return
    061         * the specified default value if a conversion error occurs.
    062         *
    063         * @param defaultValue The default value to be returned
    064         */
    065        public StringArrayConverter(Object defaultValue) {
    066
    067            this.defaultValue = defaultValue;
    068            this.useDefault = true;
    069
    070        }
    071
    072
    073        // ------------------------------------------------------- Static Variables
    074
    075
    076        /**
    077         * <p>Model object for type comparisons.</p>
    078         */
    079        private static final String[] MODEL = new String[0];
    080
    081        /**
    082         * <p> Model object for int arrays.</p>
    083         */
    084        private static final int[] INT_MODEL = new int[0];
    085
    086
    087
    088        // --------------------------------------------------------- Public Methods
    089
    090
    091        /**
    092         * Convert the specified input object into an output object of the
    093         * specified type.
    094         * <p>
    095         * If the value is already of type String[] then it is simply returned
    096         * unaltered.
    097         * <p>
    098         * If the value is of type int[], then a String[] is returned where each
    099         * 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    }