Source Code Cross Referenced for NotNull.java in  » Database-ORM » Velosurf » velosurf » validation » Java Source Code / Java DocumentationJava Source Code and Java Documentation

01:        /*
02:         * Copyright 2003 The Apache Software Foundation.
03:         *
04:         * Licensed under the Apache License, Version 2.0 (the "License");
05:         * you may not use this file except in compliance with the License.
06:         * You may obtain a copy of the License at
07:         *
08:         *     http://www.apache.org/licenses/LICENSE-2.0
09:         *
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:
17:        package velosurf.validation;
18:
19:        import java.util.Locale;
20:
21:        /**
22:         * <p>A "not null" constraint. Syntax is:</p>
23:         *  <pre>
24:         *    &lt;<i>column</i> not-null="true"/&gt;
25:         *  </pre>
26:         *<p>Or:</p><pre>
27:         *   &lt;<i>column</i>&gt;
28:         *     &lt;not-null [message="<i>error-message</i>"]/&gt;
29:         *   &lt;/<i>column</i>&gt;</pre>
30:         * <p>To validate data coming from an HTML form, you should rather use the not-empty constraint since there cannot
31:         * be any null value.</p>
32:         * <p>Note: this constraint is not meant to replace an internal SQL "not-null" clause in the database,
33:         * since it cannot be made sure that complex updates will respect this constraint.</p>
34:         *
35:         *  @author <a href="mailto:claude.brisson@gmail.com">Claude Brisson</a>
36:         */
37:        public class NotNull extends FieldConstraint {
38:
39:            /**
40:             * Default constructor.
41:             */
42:            public NotNull() {
43:                setMessage("field {0} cannot be null");
44:            }
45:
46:            /**
47:             * Validate datea against this constraint.
48:             * @param data the data to be validated
49:             * @return true if data is not null
50:             */
51:            public boolean validate(Object data) {
52:                return data != null;
53:            }
54:
55:            /**
56:             * return a string representation for this constraint.
57:             * @return string
58:             */
59:            public String toString() {
60:                return "not-null";
61:            }
62:        }