StringTypeValidator


1   /*
2    * Copyright (c) 2003, Inversoft
3    *
4    * This software is distribuable under the GNU Lesser General Public License.
5    * For more information visit gnu.org.
6    */
7   package com.inversoft.util.typevalidator;
8   
9   
10  import java.util.Locale  ;
11  import java.util.Map  ;
12  
13  
14  /**
15   * <p>
16   * A String type validator that ensures that the object is a
17   * String or can be converted to a String and also optionally
18   * checks the length of the String using the <code>min</code>
19   * and <code>max</code> parameters.
20   * </p>
21   *
22   * @author  Brian Pontarelli
23   */
24  public class StringTypeValidator extends BaseTypeValidator {
25  
26      /**
27       * The default error message
28       */
29      public static final String   DEFAULT_MESSAGE = "Invalid String";
30  
31  
32      /**
33       * Does the validation work on the String.
34       *
35       * @param   value The Object value that must be a String or convertable
36       * @param   params The parameters to get the min and max if they exist
37       * @param   message The error message if the validation fails
38       * @param   locale The locale to use when generating the error message
39       * @param   mesgParams Message params to use in formating the message
40       * @return  The message if the validation fails
41       * @throws  NumberFormatException If the params min and/or max are not numbers
42       *          or String representations of numbers
43       */
44      protected String   internalValidate(Object   value, Object   params,
45              String   message, Locale   locale, Object  [] mesgParams) {
46          if (value == null) {
47              return null;
48          }
49  
50          String   str = null;
51          boolean valid = true;
52          int length = 0;
53          try {
54              str = value.toString();
55              length = (str == null) ? 0 : str.length();
56          } catch (Exception   e) {
57              valid = false;
58          }
59  
60          if (valid && length > 0 && params != null) {
61              Object   min = ((Map  ) params).get("min");
62              Object   max = ((Map  ) params).get("max");
63              if (min != null) {
64                  if (!(min instanceof Number  )) {
65                      try {
66                          min = Double.valueOf(min.toString());
67                      } catch (NumberFormatException   nfe) {
68                          throw new NumberFormatException  ("Invalid min value: " +
69                              min);
70                      }
71                  }
72  
73                  if (min != null) {
74                      if (length < (((Number  ) min).doubleValue())) {
75                          valid = false;
76                      }
77                  }
78              }
79  
80              if (max != null) {
81                  if (!(max instanceof Number  )) {
82                      try {
83                          max = Double.valueOf(max.toString());
84                      } catch (NumberFormatException   nfe) {
85                          throw new NumberFormatException  ("Invalid max value: " +
86                              max);
87                      }
88                  }
89  
90                  if (max != null) {
91                      if (length > (((Number  ) max).doubleValue())) {
92                          valid = false;
93                      }
94                  }
95              }
96          }
97  
98          String   error = null;
99          if (!valid) {
100             error = getErrorMessage(message, DEFAULT_MESSAGE, mesgParams);
101         }
102 
103         return error;
104     }
105 }
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