1 /*
2  * Copyright (C) 2010 The Android Open Source Project
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 
17 package tests.util;
18 
19 /**
20  * Pair of typed values.
21  *
22  * <p>Pairs are obtained using {@link #of(Object, Object) of}.
23  *
24  * @param <F> type of the first value.
25  * @param <S> type of the second value.
26  */
27 public class Pair<F, S> {
28   private final F mFirst;
29   private final S mSecond;
30 
Pair(F first, S second)31   private Pair(F first, S second) {
32     mFirst = first;
33     mSecond = second;
34   }
35 
36   /**
37    * Gets the pair consisting of the two provided values.
38    *
39    * @param first first value or {@code null}.
40    * @param second second value or {@code null}.
41    */
of(F first, S second)42   public static <F, S> Pair<F, S> of(F first, S second) {
43     return new Pair<F, S>(first, second);
44   }
45 
46   /**
47    * Gets the first value from this pair.
48    *
49    * @return value or {@code null}.
50    */
getFirst()51   public F getFirst() {
52     return mFirst;
53   }
54 
55   /**
56    * Gets the second value from this pair.
57    *
58    * @return value or {@code null}.
59    */
getSecond()60   public S getSecond() {
61     return mSecond;
62   }
63 
64   @Override
toString()65   public String toString() {
66     return "Pair[" + mFirst + ", " + mSecond + "]";
67   }
68 
69   @Override
hashCode()70   public int hashCode() {
71     final int prime = 31;
72     int result = 1;
73     result = prime * result + ((mFirst == null) ? 0 : mFirst.hashCode());
74     result = prime * result + ((mSecond == null) ? 0 : mSecond.hashCode());
75     return result;
76   }
77 
78   @Override
equals(Object obj)79   public boolean equals(Object obj) {
80     if (this == obj) {
81       return true;
82     }
83     if (obj == null) {
84       return false;
85     }
86     if (getClass() != obj.getClass()) {
87       return false;
88     }
89     @SuppressWarnings("rawtypes")
90     Pair other = (Pair) obj;
91     if (mFirst == null) {
92       if (other.mFirst != null) {
93         return false;
94       }
95     } else if (!mFirst.equals(other.mFirst)) {
96       return false;
97     }
98     if (mSecond == null) {
99       if (other.mSecond != null) {
100         return false;
101       }
102     } else if (!mSecond.equals(other.mSecond)) {
103       return false;
104     }
105     return true;
106   }
107 }
108