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;
17
18 import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
19 import static java.lang.annotation.ElementType.FIELD;
20 import static java.lang.annotation.ElementType.METHOD;
21 import static java.lang.annotation.RetentionPolicy.RUNTIME;
22
23 import java.lang.annotation.Documented;
24 import java.lang.annotation.Retention;
25 import java.lang.annotation.Target;
26
27 import javax.validation.Constraint;
28 import javax.validation.Payload;
29
30 import de.smartics.validation.constraints.impl.NullButNotBlankValidator;
31
32 /**
33 * The annotated element of type {@link String} may be <code>null</code>, but if
34 * not <code>null</code> it must not be empty or contain only whitespaces.
35 * <p>
36 * Only {@link String} values are allowed.
37 * </p>
38 */
39 @Target(
40 { METHOD, FIELD, ANNOTATION_TYPE })
41 @Retention(RUNTIME)
42 @Documented
43 @Constraint(validatedBy = NullButNotBlankValidator.class)
44 public @interface NullButNotBlank
45 {
46 // ********************************* Fields *********************************
47
48 /**
49 * The key of the message rendered, if the constraint has been violated.
50 * <p>
51 * The value of this constant is {@value}.
52 * </p>
53 */
54 String MESSAGE_KEY =
55 "{de.smartics.validation.constraints.NullButNotBlank.message}";
56
57 // ********************************* Methods ********************************
58
59 /**
60 * Returns the message key to be rendered, if the constraint has been
61 * violated.
62 * <p>
63 * Defaults to returning {@value #MESSAGE_KEY}.
64 * </p>
65 */
66 String message() default MESSAGE_KEY;
67
68 /**
69 * Support of validation groups.
70 */
71 Class<?>[] groups() default {};
72
73 /**
74 * Support of payloads.
75 */
76 Class<? extends Payload>[] payload() default {};
77
78 }