1 package org.apache.onami.persist;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 /**
23 * Checks to ensure arguments are in a valid state.
24 */
25 class Preconditions
26 {
27
28 /**
29 * Check that a reference is not null.
30 *
31 * @param <T> the type of the reference
32 * @param reference the reference to check.
33 * @return the reference itself.
34 * @throws NullPointerException if the reference is null.
35 */
36 static <T> T checkNotNull( T reference )
37 {
38 if ( reference == null )
39 {
40 throw new NullPointerException();
41 }
42 return reference;
43 }
44
45 /**
46 * Check that a reference is not null.
47 *
48 * @param <T> the type of the reference
49 * @param reference the reference to check.
50 * @param message the message of the NullPointerException if one is thrown.
51 * @return the reference itself.
52 * @throws NullPointerException if the reference is null.
53 */
54 static <T> T checkNotNull( T reference, String message )
55 {
56 if ( reference == null )
57 {
58 throw new NullPointerException( message );
59 }
60 return reference;
61 }
62
63 }