1 /*
2 * Copyright 2009-2013 smartics, Kronseder & Reiner GmbH
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package de.smartics.validation.constraints.impl;
17
18 import javax.validation.ConstraintValidator;
19 import javax.validation.ConstraintValidatorContext;
20
21 import org.apache.commons.lang.StringUtils;
22
23 import de.smartics.validation.constraints.NullButNotBlank;
24
25 /**
26 * Check that the {@link String} value is either <code>null</code> or, if not
27 * <code>null</code>, it is not empty or contains only whitespaces.
28 */
29 public class NullButNotBlankValidator implements
30 ConstraintValidator<NullButNotBlank, String>
31 {
32 // ******************************** Fields ********************************
33
34 // --- constants ----------------------------------------------------------
35
36 // --- members ------------------------------------------------------------
37
38 // ***************************** Initializer ******************************
39
40 // ***************************** Constructors *****************************
41
42 // ***************************** Inner Classes ****************************
43
44 // ******************************** Methods *******************************
45
46 // --- init ---------------------------------------------------------------
47
48 @Override
49 public void initialize(final NullButNotBlank constraintAnnotation)
50 {
51 }
52
53 // --- get&set ------------------------------------------------------------
54
55 // --- business -----------------------------------------------------------
56
57 @Override
58 public boolean isValid(
59 final String value,
60 final ConstraintValidatorContext constraintValidatorContext)
61 {
62 return value == null || StringUtils.isNotBlank(value);
63 }
64
65 // --- object basics ------------------------------------------------------
66
67 }