1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.maven.api.services;
20
21 import java.util.ArrayList;
22 import java.util.Collection;
23 import java.util.Collections;
24 import org.apache.maven.api.Session;
25 import org.apache.maven.api.annotations.Experimental;
26 import org.apache.maven.api.annotations.Nonnull;
27
28 /**
29 * Base class for requests.
30 *
31 * @since 4.0
32 */
33 @Experimental
34 abstract class BaseRequest {
35
36 private final Session session;
37
38 protected BaseRequest(@Nonnull Session session) {
39 this.session = nonNull(session, "session cannot be null");
40 }
41
42 @Nonnull
43 public Session getSession() {
44 return session;
45 }
46
47 public static <T> T nonNull(T obj, String message) {
48 if (obj == null) {
49 throw new IllegalArgumentException(message);
50 }
51 return obj;
52 }
53
54 protected static <T> Collection<T> unmodifiable(Collection<T> obj) {
55 return obj != null && !obj.isEmpty()
56 ? Collections.unmodifiableCollection(new ArrayList<>(obj))
57 : Collections.emptyList();
58 }
59 }