Method: characteristics()

1: /*
2: * *********************************************************************************************************************
3: *
4: * TheseFoolishThings: Miscellaneous utilities
5: * http://tidalwave.it/projects/thesefoolishthings
6: *
7: * Copyright (C) 2009 - 2023 by Tidalwave s.a.s. (http://tidalwave.it)
8: *
9: * *********************************************************************************************************************
10: *
11: * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
12: * the License. You may obtain a copy of the License at
13: *
14: * http://www.apache.org/licenses/LICENSE-2.0
15: *
16: * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
17: * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
18: * specific language governing permissions and limitations under the License.
19: *
20: * *********************************************************************************************************************
21: *
22: * git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
23: * git clone https://github.com/tidalwave-it/thesefoolishthings-src
24: *
25: * *********************************************************************************************************************
26: */
27: package it.tidalwave.util.spi;
28:
29: import javax.annotation.Nonnull;
30: import java.util.ArrayList;
31: import java.util.Collections;
32: import java.util.List;
33: import java.util.Set;
34: import java.util.function.BiConsumer;
35: import java.util.function.BinaryOperator;
36: import java.util.function.Supplier;
37: import java.util.stream.Collector;
38:
39: /***********************************************************************************************************************
40: *
41: * A support {@link Collector} which uses an {@link ArrayList} as the accumulator.
42: *
43: * @param <COLLECTED_TYPE> the type of collected items
44: * @param <COLLECTING_TYPE> the type of collecting item
45: *
46: * @author Fabrizio Giudici
47: *
48: **********************************************************************************************************************/
49: public abstract class ArrayListCollectorSupport<COLLECTED_TYPE, COLLECTING_TYPE>
50: implements Collector<COLLECTED_TYPE, List<COLLECTED_TYPE>, COLLECTING_TYPE>
51: {
52: @Override @Nonnull
53: public Supplier<List<COLLECTED_TYPE>> supplier()
54: {
55: return ArrayList::new;
56: }
57:
58: @Override @Nonnull
59: public BiConsumer<List<COLLECTED_TYPE>, COLLECTED_TYPE> accumulator()
60: {
61: return List::add;
62: }
63:
64: @Override @Nonnull
65: public BinaryOperator<List<COLLECTED_TYPE>> combiner()
66: {
67: return (left, right) -> { left.addAll(right); return left; };
68: }
69:
70: @Override @Nonnull
71: public Set<Characteristics> characteristics()
72: {
73: // Not CONCURRENT since ArrayList is not thread-safe
74: return Collections.emptySet();
75: }
76: }