1 /*
2 * $Id: ParameterValidator.java [15-May-2004]
3 *
4 * Copyright (c) 2004, Ben Fortuna
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * o Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 *
14 * o Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * o Neither the name of Ben Fortuna nor the names of any other contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
25 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
26 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
27 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
28 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
29 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34 package net.fortuna.ical4j.util;
35
36 import net.fortuna.ical4j.model.ParameterList;
37 import net.fortuna.ical4j.model.ValidationException;
38
39 /***
40 * Defines methods for validating parameters and parameter
41 * lists.
42 * @author benfortuna
43 */
44 public final class ParameterValidator {
45
46 private static ParameterValidator instance = new ParameterValidator();
47
48 /***
49 * Constructor made private to enforce singleton.
50 */
51 private ParameterValidator() {
52 }
53
54 /***
55 * Ensure a parameter occurs no more than once.
56 *
57 * @param paramName
58 * the parameter name
59 * @param parameters
60 * a list of parameters to query
61 * @throws ValidationException
62 * when the specified parameter occurs more than once
63 */
64 public void validateOneOrLess(final String paramName,
65 final ParameterList parameters) throws ValidationException {
66
67 if (parameters.getParameters(paramName).size() > 1) {
68 throw new ValidationException(
69 "Parameter [" + paramName + "] must only be specified once");
70 }
71 }
72
73 /***
74 * Ensure a parameter occurs once.
75 *
76 * @param paramName
77 * the parameter name
78 * @param parameters
79 * a list of parameters to query
80 * @throws ValidationException
81 * when the specified parameter does not occur once
82 */
83 public void validateOne(final String paramName,
84 final ParameterList parameters) throws ValidationException {
85
86 if (parameters.getParameters(paramName).size() != 1) {
87 throw new ValidationException(
88 "Parameter [" + paramName + "] must be specified once");
89 }
90 }
91
92 /***
93 * @return Returns the instance.
94 */
95 public static ParameterValidator getInstance() {
96 return instance;
97 }
98 }