1 /*
2 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.util.stream;
27
28 import java.util.Comparator;
29 import java.util.Iterator;
30 import java.util.Objects;
31 import java.util.Optional;
32 import java.util.Spliterator;
33 import java.util.function.BiConsumer;
34 import java.util.function.BiFunction;
35 import java.util.function.BinaryOperator;
36 import java.util.function.Consumer;
37 import java.util.function.Function;
38 import java.util.function.IntFunction;
39 import java.util.function.Predicate;
40 import java.util.function.Supplier;
41 import java.util.function.ToDoubleFunction;
42 import java.util.function.ToIntFunction;
43 import java.util.function.ToLongFunction;
44
45 /**
46 * A {@code Stream} implementation that delegates operations to another {@code
47 * Stream}.
48 *
49 * @param <T> type of stream elements for this stream and underlying delegate
50 * stream
51 *
52 * @since 1.8
53 */
54 public class DelegatingStream<T> implements Stream<T> {
55 final private Stream<T> delegate;
56
57 /**
58 * Construct a {@code Stream} that delegates operations to another {@code
59 * Stream}.
60 *
61 * @param delegate the underlying {@link Stream} to which we delegate all
62 * {@code Stream} methods
63 * @throws NullPointerException if the delegate is null
64 */
65 public DelegatingStream(Stream<T> delegate) {
66 this.delegate = Objects.requireNonNull(delegate);
67 }
68
69 // -- BaseStream methods --
70
71 @Override
72 public Spliterator<T> spliterator() {
73 return delegate.spliterator();
74 }
75
76 @Override
77 public boolean isParallel() {
78 return delegate.isParallel();
79 }
80
81 @Override
82 public Iterator<T> iterator() {
83 return delegate.iterator();
84 }
85
86 // -- Stream methods --
87
88 @Override
89 public Stream<T> filter(Predicate<? super T> predicate) {
90 return delegate.filter(predicate);
91 }
92
93 @Override
94 public <R> Stream<R> map(Function<? super T, ? extends R> mapper) {
95 return delegate.map(mapper);
96 }
97
98 @Override
99 public IntStream mapToInt(ToIntFunction<? super T> mapper) {
100 return delegate.mapToInt(mapper);
101 }
102
103 @Override
104 public LongStream mapToLong(ToLongFunction<? super T> mapper) {
105 return delegate.mapToLong(mapper);
106 }
107
108 @Override
109 public DoubleStream mapToDouble(ToDoubleFunction<? super T> mapper) {
110 return delegate.mapToDouble(mapper);
111 }
112
113 @Override
114 public <R> Stream<R> flatMap(Function<? super T, ? extends Stream<? extends R>> mapper) {
115 return delegate.flatMap(mapper);
116 }
117
118 @Override
119 public IntStream flatMapToInt(Function<? super T, ? extends IntStream> mapper) {
120 return delegate.flatMapToInt(mapper);
121 }
122
123 @Override
124 public LongStream flatMapToLong(Function<? super T, ? extends LongStream> mapper) {
125 return delegate.flatMapToLong(mapper);
126 }
127
128 @Override
129 public DoubleStream flatMapToDouble(Function<? super T, ? extends DoubleStream> mapper) {
130 return delegate.flatMapToDouble(mapper);
131 }
132
133 @Override
134 public Stream<T> distinct() {
135 return delegate.distinct();
136 }
137
138 @Override
139 public Stream<T> sorted() {
140 return delegate.sorted();
141 }
142
143 @Override
144 public Stream<T> sorted(Comparator<? super T> comparator) {
145 return delegate.sorted(comparator);
146 }
147
148 @Override
149 public void forEach(Consumer<? super T> action) {
150 delegate.forEach(action);
151 }
152
153 @Override
154 public void forEachOrdered(Consumer<? super T> action) {
155 delegate.forEachOrdered(action);
156 }
157
158 @Override
159 public Stream<T> peek(Consumer<? super T> consumer) {
160 return delegate.peek(consumer);
161 }
162
163 @Override
164 public Stream<T> limit(long maxSize) {
165 return delegate.limit(maxSize);
166 }
167
168 @Override
169 public Stream<T> substream(long startingOffset) {
170 return delegate.substream(startingOffset);
171 }
172
173 @Override
174 public Stream<T> substream(long startingOffset, long endingOffset) {
175 return delegate.substream(startingOffset, endingOffset);
176 }
177
178 @Override
179 public <A> A[] toArray(IntFunction<A[]> generator) {
180 return delegate.toArray(generator);
181 }
182
183 @Override
184 public Object[] toArray() {
185 return delegate.toArray();
186 }
187
188 @Override
189 public T reduce(T identity, BinaryOperator<T> accumulator) {
190 return delegate.reduce(identity, accumulator);
191 }
192
193 @Override
194 public Optional<T> reduce(BinaryOperator<T> accumulator) {
195 return delegate.reduce(accumulator);
196 }
197
198 @Override
199 public <U> U reduce(U identity, BiFunction<U, ? super T, U> accumulator,
200 BinaryOperator<U> combiner) {
201 return delegate.reduce(identity, accumulator, combiner);
202 }
203
204 @Override
205 public <R> R collect(Supplier<R> resultFactory,
206 BiConsumer<R, ? super T> accumulator,
207 BiConsumer<R, R> combiner) {
208 return delegate.collect(resultFactory, accumulator, combiner);
209 }
210
211 @Override
212 public <R, A> R collect(Collector<? super T, A, ? extends R> collector) {
213 return delegate.collect(collector);
214 }
215
216 @Override
217 public Optional<T> max(Comparator<? super T> comparator) {
218 return delegate.max(comparator);
219 }
220
221 @Override
222 public Optional<T> min(Comparator<? super T> comparator) {
223 return delegate.min(comparator);
224 }
225
226 @Override
227 public long count() {
228 return delegate.count();
229 }
230
231 @Override
232 public boolean anyMatch(Predicate<? super T> predicate) {
233 return delegate.anyMatch(predicate);
234 }
235
236 @Override
237 public boolean allMatch(Predicate<? super T> predicate) {
238 return delegate.allMatch(predicate);
239 }
240
241 @Override
242 public boolean noneMatch(Predicate<? super T> predicate) {
243 return delegate.noneMatch(predicate);
244 }
245
246 @Override
247 public Optional<T> findFirst() {
248 return delegate.findFirst();
249 }
250
251 @Override
252 public Optional<T> findAny() {
253 return delegate.findAny();
254 }
255
256 @Override
257 public Stream<T> unordered() {
258 return delegate.unordered();
259 }
260
261 @Override
262 public Stream<T> sequential() {
263 return delegate.sequential();
264 }
265
266 @Override
267 public Stream<T> parallel() {
268 return delegate.parallel();
269 }
270 }