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 package org.apache.commons.beanutils.locale;
019
020 import org.apache.commons.beanutils.ConversionException;
021 import org.apache.commons.logging.Log;
022 import org.apache.commons.logging.LogFactory;
023
024 import java.text.ParseException;
025 import java.util.Locale;
026
027
028 /**
029 * <p>The base class for all standart type locale-sensitive converters.
030 * It has {@link LocaleConverter} and {@link org.apache.commons.beanutils.Converter} implementations,
031 * that convert an incoming locale-sensitive Object into an object of correspond type,
032 * optionally using a default value or throwing a {@link ConversionException}
033 * if a conversion error occurs.</p>
034 *
035 * @author Yauheny Mikulski
036 */
037
038 public abstract class BaseLocaleConverter implements LocaleConverter {
039
040 // ----------------------------------------------------- Instance Variables
041
042 /** All logging goes through this logger */
043 private Log log = LogFactory.getLog(BaseLocaleConverter.class);
044
045 /** The default value specified to our Constructor, if any. */
046 private Object defaultValue = null;
047
048 /** Should we return the default value on conversion errors? */
049 protected boolean useDefault = false;
050
051 /** The locale specified to our Constructor, by default - system locale. */
052 protected Locale locale = Locale.getDefault();
053
054 /** The default pattern specified to our Constructor, if any. */
055 protected String pattern = null;
056
057 /** The flag indicating whether the given pattern string is localized or not. */
058 protected boolean locPattern = false;
059
060 // ----------------------------------------------------------- Constructors
061
062 /**
063 * Create a {@link LocaleConverter} that will throw a {@link ConversionException}
064 * if a conversion error occurs.
065 * An unlocalized pattern is used for the convertion.
066 *
067 * @param locale The locale
068 * @param pattern The convertion pattern
069 */
070 protected BaseLocaleConverter(Locale locale, String pattern) {
071
072 this(null, locale, pattern, false, false);
073 }
074
075 /**
076 * Create a {@link LocaleConverter} that will throw a {@link ConversionException}
077 * if a conversion error occurs.
078 *
079 * @param locale The locale
080 * @param pattern The convertion pattern
081 * @param locPattern Indicate whether the pattern is localized or not
082 */
083 protected BaseLocaleConverter(Locale locale, String pattern, boolean locPattern) {
084
085 this(null, locale, pattern, false, locPattern);
086 }
087
088 /**
089 * Create a {@link LocaleConverter} that will return the specified default value
090 * if a conversion error occurs.
091 * An unlocalized pattern is used for the convertion.
092 *
093 * @param defaultValue The default value to be returned
094 * @param locale The locale
095 * @param pattern The convertion pattern
096 */
097 protected BaseLocaleConverter(Object defaultValue, Locale locale, String pattern) {
098
099 this(defaultValue, locale, pattern, false);
100 }
101
102 /**
103 * Create a {@link LocaleConverter} that will return the specified default value
104 * if a conversion error occurs.
105 *
106 * @param defaultValue The default value to be returned
107 * @param locale The locale
108 * @param pattern The convertion pattern
109 * @param locPattern Indicate whether the pattern is localized or not
110 */
111 protected BaseLocaleConverter(Object defaultValue, Locale locale, String pattern, boolean locPattern) {
112
113 this(defaultValue, locale, pattern, true, locPattern);
114 }
115
116 /**
117 * Create a {@link LocaleConverter} that will return the specified default value
118 * or throw a {@link ConversionException} if a conversion error occurs.
119 *
120 * @param defaultValue The default value to be returned
121 * @param locale The locale
122 * @param pattern The convertion pattern
123 * @param useDefault Indicate whether the default value is used or not
124 * @param locPattern Indicate whether the pattern is localized or not
125 */
126 private BaseLocaleConverter(Object defaultValue, Locale locale,
127 String pattern, boolean useDefault, boolean locPattern) {
128
129 if (useDefault) {
130 this.defaultValue = defaultValue;
131 this.useDefault = true;
132 }
133
134 if (locale != null) {
135 this.locale = locale;
136 }
137
138 this.pattern = pattern;
139 this.locPattern = locPattern;
140 }
141
142 // --------------------------------------------------------- Methods
143
144 /**
145 * Convert the specified locale-sensitive input object into an output object of the
146 * specified type.
147 *
148 * @param value The input object to be converted
149 * @param pattern The pattern is used for the convertion
150 * @return The converted value
151 *
152 * @exception ParseException if conversion cannot be performed
153 * successfully
154 */
155
156 abstract protected Object parse(Object value, String pattern) throws ParseException;
157
158
159 /**
160 * Convert the specified locale-sensitive input object into an output object.
161 * The default pattern is used for the convertion.
162 *
163 * @param value The input object to be converted
164 * @return The converted value
165 *
166 * @exception ConversionException if conversion cannot be performed
167 * successfully
168 */
169 public Object convert(Object value) {
170 return convert(value, null);
171 }
172
173 /**
174 * Convert the specified locale-sensitive input object into an output object.
175 *
176 * @param value The input object to be converted
177 * @param pattern The pattern is used for the convertion
178 * @return The converted value
179 *
180 * @exception ConversionException if conversion cannot be performed
181 * successfully
182 */
183 public Object convert(Object value, String pattern) {
184 return convert(null, value, pattern);
185 }
186
187 /**
188 * Convert the specified locale-sensitive input object into an output object of the
189 * specified type. The default pattern is used for the convertion.
190 *
191 * @param type Data type to which this value should be converted
192 * @param value The input object to be converted
193 * @return The converted value
194 *
195 * @exception ConversionException if conversion cannot be performed
196 * successfully
197 */
198 public Object convert(Class type, Object value) {
199 return convert(type, value, null);
200 }
201
202 /**
203 * Convert the specified locale-sensitive input object into an output object of the
204 * specified type.
205 *
206 * @param type Data is type to which this value should be converted
207 * @param value is the input object to be converted
208 * @param pattern is the pattern is used for the conversion; if null is
209 * passed then the default pattern associated with the converter object
210 * will be used.
211 * @return The converted value
212 *
213 * @exception ConversionException if conversion cannot be performed
214 * successfully
215 */
216 public Object convert(Class type, Object value, String pattern) {
217 if (value == null) {
218 if (useDefault) {
219 return (defaultValue);
220 } else {
221 // symmetric beanutils function allows null
222 // so do not: throw new ConversionException("No value specified");
223 log.debug("Null value specified for conversion, returing null");
224 return null;
225 }
226 }
227
228 try {
229 if (pattern != null) {
230 return parse(value, pattern);
231 } else {
232 return parse(value, this.pattern);
233 }
234 } catch (Exception e) {
235 if (useDefault) {
236 return (defaultValue);
237 } else {
238 if (e instanceof ConversionException) {
239 throw (ConversionException)e;
240 }
241 throw new ConversionException(e);
242 }
243 }
244 }
245 }