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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.validator.routines;
18  
19  import java.text.Format;
20  import java.util.Locale;
21  
22  /***
23   * <p><b>Double Validation</b> and Conversion routines (<code>java.lang.Double</code>).</p>
24   *
25   * <p>This validator provides a number of methods for
26   *    validating/converting a <code>String</code> value to
27   *    a <code>Double</code> using <code>java.text.NumberFormat</code>
28   *    to parse either:</p>
29   *    <ul>
30   *       <li>using the default format for the default <code>Locale</code></li>
31   *       <li>using a specified pattern with the default <code>Locale</code></li>
32   *       <li>using the default format for a specified <code>Locale</code></li>
33   *       <li>using a specified pattern with a specified <code>Locale</code></li>
34   *    </ul>
35   *    
36   * <p>Use one of the <code>isValid()</code> methods to just validate or
37   *    one of the <code>validate()</code> methods to validate and receive a
38   *    <i>converted</i> <code>Double</code> value.</p>
39   * 
40   * <p>Once a value has been sucessfully converted the following
41   *    methods can be used to perform minimum, maximum and range checks:</p>
42   *    <ul>
43   *       <li><code>minValue()</code> checks whether the value is greater
44   *           than or equal to a specified minimum.</li>
45   *       <li><code>maxValue()</code> checks whether the value is less
46   *           than or equal to a specified maximum.</li>
47   *       <li><code>isInRange()</code> checks whether the value is within
48   *           a specified range of values.</li>
49   *    </ul>
50   * 
51   * <p>So that the same mechanism used for parsing an <i>input</i> value 
52   *    for validation can be used to format <i>output</i>, corresponding
53   *    <code>format()</code> methods are also provided. That is you can 
54   *    format either:</p>
55   *    <ul>
56   *       <li>using the default format for the default <code>Locale</code></li>
57   *       <li>using a specified pattern with the default <code>Locale</code></li>
58   *       <li>using the default format for a specified <code>Locale</code></li>
59   *       <li>using a specified pattern with a specified <code>Locale</code></li>
60   *    </ul>
61   *
62   * @version $Revision: 478334 $ $Date: 2006-11-22 21:31:54 +0000 (Wed, 22 Nov 2006) $
63   * @since Validator 1.3.0
64   */
65  public class DoubleValidator extends AbstractNumberValidator {
66  
67      private static final DoubleValidator VALIDATOR = new DoubleValidator();
68  
69      /***
70       * Return a singleton instance of this validator.
71       * @return A singleton instance of the DoubleValidator.
72       */
73      public static DoubleValidator getInstance() {
74          return VALIDATOR;
75      }
76  
77      /***
78       * Construct a <i>strict</i> instance.
79       */
80      public DoubleValidator() {
81          this(true, STANDARD_FORMAT);
82      }
83  
84      /***
85       * <p>Construct an instance with the specified strict setting
86       *    and format type.</p>
87       *    
88       * <p>The <code>formatType</code> specified what type of
89       *    <code>NumberFormat</code> is created - valid types
90       *    are:</p>
91       *    <ul>
92       *       <li>AbstractNumberValidator.STANDARD_FORMAT -to create
93       *           <i>standard</i> number formats (the default).</li>
94       *       <li>AbstractNumberValidator.CURRENCY_FORMAT -to create
95       *           <i>currency</i> number formats.</li>
96       *       <li>AbstractNumberValidator.PERCENT_FORMAT -to create
97       *           <i>percent</i> number formats (the default).</li>
98       *    </ul>
99       * 
100      * @param strict <code>true</code> if strict 
101      *        <code>Format</code> parsing should be used.
102      * @param formatType The <code>NumberFormat</code> type to
103      *        create for validation, default is STANDARD_FORMAT.
104      */
105     public DoubleValidator(boolean strict, int formatType) {
106         super(strict, formatType, true);
107     }
108 
109     /***
110      * <p>Validate/convert a <code>Double</code> using the default
111      *    <code>Locale</code>. 
112      *
113      * @param value The value validation is being performed on.
114      * @return The parsed <code>Double</code> if valid or <code>null</code>
115      *  if invalid.
116      */
117     public Double validate(String value) {
118         return (Double)parse(value, (String)null, (Locale)null);
119     }
120 
121     /***
122      * <p>Validate/convert a <code>Double</code> using the
123      *    specified <i>pattern</i>. 
124      *
125      * @param value The value validation is being performed on.
126      * @param pattern The pattern used to validate the value against.
127      * @return The parsed <code>BigDecimal</code> if valid or <code>null</code> if invalid.
128      */
129     public Double validate(String value, String pattern) {
130         return (Double)parse(value, pattern, (Locale)null);
131     }
132 
133     /***
134      * <p>Validate/convert a <code>Double</code> using the
135      *    specified <code>Locale</code>. 
136      *
137      * @param value The value validation is being performed on.
138      * @param locale The locale to use for the number format, system default if null.
139      * @return The parsed <code>Double</code> if valid or <code>null</code> if invalid.
140      */
141     public Double validate(String value, Locale locale) {
142         return (Double)parse(value, (String)null, locale);
143     }
144 
145     /***
146      * <p>Validate/convert a <code>Double</code> using the
147      *    specified pattern and/ or <code>Locale</code>. 
148      *
149      * @param value The value validation is being performed on.
150      * @param pattern The pattern used to validate the value against, or the
151      *        default for the <code>Locale</code> if <code>null</code>.
152      * @param locale The locale to use for the date format, system default if null.
153      * @return The parsed <code>Double</code> if valid or <code>null</code> if invalid.
154      */
155     public Double validate(String value, String pattern, Locale locale) {
156         return (Double)parse(value, pattern, locale);
157     }
158 
159     /***
160      * Check if the value is within a specified range.
161      * 
162      * @param value The <code>Number</code> value to check.
163      * @param min The minimum value of the range.
164      * @param max The maximum value of the range.
165      * @return <code>true</code> if the value is within the
166      *         specified range.
167      */
168     public boolean isInRange(double value, double min, double max) {
169         return (value >= min && value <= max);
170     }
171 
172     /***
173      * Check if the value is within a specified range.
174      * 
175      * @param value The <code>Number</code> value to check.
176      * @param min The minimum value of the range.
177      * @param max The maximum value of the range.
178      * @return <code>true</code> if the value is within the
179      *         specified range.
180      */
181     public boolean isInRange(Double value, double min, double max) {
182         return isInRange(value.doubleValue(), min, max);
183     }
184 
185     /***
186      * Check if the value is greater than or equal to a minimum.
187      * 
188      * @param value The value validation is being performed on.
189      * @param min The minimum value.
190      * @return <code>true</code> if the value is greater than
191      *         or equal to the minimum.
192      */
193     public boolean minValue(double value, double min) {
194         return (value >= min);
195     }
196 
197     /***
198      * Check if the value is greater than or equal to a minimum.
199      * 
200      * @param value The value validation is being performed on.
201      * @param min The minimum value.
202      * @return <code>true</code> if the value is greater than
203      *         or equal to the minimum.
204      */
205     public boolean minValue(Double value, double min) {
206         return minValue(value.doubleValue(), min);
207     }
208 
209     /***
210      * Check if the value is less than or equal to a maximum.
211      * 
212      * @param value The value validation is being performed on.
213      * @param max The maximum value.
214      * @return <code>true</code> if the value is less than
215      *         or equal to the maximum.
216      */
217     public boolean maxValue(double value, double max) {
218         return (value <= max);
219     }
220 
221     /***
222      * Check if the value is less than or equal to a maximum.
223      * 
224      * @param value The value validation is being performed on.
225      * @param max The maximum value.
226      * @return <code>true</code> if the value is less than
227      *         or equal to the maximum.
228      */
229     public boolean maxValue(Double value, double max) {
230         return maxValue(value.doubleValue(), max);
231     }
232 
233     /***
234      * Convert the parsed value to a <code>Double</code>.
235      * 
236      * @param value The parsed <code>Number</code> object created.
237      * @param formatter The Format used to parse the value with.
238      * @return The validated/converted <code>Double</code> value if valid 
239      * or <code>null</code> if invalid.
240      */
241     protected Object processParsedValue(Object value, Format formatter) {
242 
243         if (value instanceof Double) {
244             return value;
245         } else {
246             return new Double(((Number)value).doubleValue());
247         }
248 
249     }
250 }