Coverage Summary for Class: Present (com.google.common.base)

1 /*
2  * Copyright (C) 2011 The Guava Authors
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5  * in compliance with the License. You may obtain a copy of the License at
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software distributed under the License
10  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11  * or implied. See the License for the specific language governing permissions and limitations under
12  * the License.
13  */
14 
15 package com.google.common.base;
16 
17 import static com.google.common.base.Preconditions.checkNotNull;
18 
19 import com.google.common.annotations.GwtCompatible;
20 import java.util.Collections;
21 import java.util.Set;
22 import javax.annotation.CheckForNull;
23 
24 /** Implementation of an {@link Optional} containing a reference. */
25 @GwtCompatible
26 @ElementTypesAreNonnullByDefault
27 final class Present<T> extends Optional<T> {
28   private final T reference;
29 
30   Present(T reference) {
31     this.reference = reference;
32   }
33 
34   @Override
35   public boolean isPresent() {
36     return true;
37   }
38 
39   @Override
40   public T get() {
41     return reference;
42   }
43 
44   @Override
45   public T or(T defaultValue) {
46     checkNotNull(defaultValue, "use Optional.orNull() instead of Optional.or(null)");
47     return reference;
48   }
49 
50   @Override
51   public Optional<T> or(Optional<? extends T> secondChoice) {
52     checkNotNull(secondChoice);
53     return this;
54   }
55 
56   @Override
57   public T or(Supplier<? extends T> supplier) {
58     checkNotNull(supplier);
59     return reference;
60   }
61 
62   @Override
63   public T orNull() {
64     return reference;
65   }
66 
67   @Override
68   public Set<T> asSet() {
69     return Collections.singleton(reference);
70   }
71 
72   @Override
73   public <V> Optional<V> transform(Function<? super T, V> function) {
74     return new Present<V>(
75         checkNotNull(
76             function.apply(reference),
77             "the Function passed to Optional.transform() must not return null."));
78   }
79 
80   @Override
81   public boolean equals(@CheckForNull Object object) {
82     if (object instanceof Present) {
83       Present<?> other = (Present<?>) object;
84       return reference.equals(other.reference);
85     }
86     return false;
87   }
88 
89   @Override
90   public int hashCode() {
91     return 0x598df91c + reference.hashCode();
92   }
93 
94   @Override
95   public String toString() {
96     return "Optional.of(" + reference + ")";
97   }
98 
99   private static final long serialVersionUID = 0;
100 }