1 /*
2 * Copyright (c) 2020, 2024, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 /*
25 * @test
26 * @summary Basic stream tests to iterate on nullable and null-restricted values
27 * @enablePreview
28 * @run junit/othervm StreamTest
29 */
30
31 import jdk.internal.vm.annotation.ImplicitlyConstructible;
32 import jdk.internal.vm.annotation.NullRestricted;
33
34 import java.util.Arrays;
35 import java.util.List;
36 import java.util.stream.Stream;
37
38 import org.junit.jupiter.api.Test;
39 import static org.junit.jupiter.api.Assertions.*;
40
41 public class StreamTest {
42
43 static value class X {
44 int x;
45 X(int x) {
46 this.x = x;
47 }
48 int x() {
49 return x;
50 }
51 }
52
53 @ImplicitlyConstructible
54 static value class Point {
55 public int x;
56 public int y;
57 Point(int x, int y) {
58 this.x = x;
59 this.y = y;
60 }
61 }
62
63 @ImplicitlyConstructible
64 static value class Value {
65 int i;
66 @NullRestricted
67 Point p;
68 Point nullable;
69 List<X> list;
70 Value(int i, Point/* Point! */ p, Point np, List<X> list) {
71 this.i = i;
72 this.p = p;
73 this.nullable = np;
74 this.list = list;
75 }
76
77 Point point() {
78 return p;
79 }
80
81 Point nullablePoint() {
82 return nullable;
83 }
84
85 int getI() { return i; }
86
87 List<X> list() { return list; }
88 }
89
90 final Value[] values = init();
91 private Value[] init() {
92 Value[] values = new Value[10];
93 for (int i = 0; i < 10; i++) {
94 values[i] = new Value(i,
95 new Point(i,i*2),
96 (i%2) == 0 ? null : new Point(i*10, i*20),
97 List.of(new X(i), new X(i*10)));
98 }
99 return values;
100 }
101
102 @Test
103 public void testValues() {
104 Arrays.stream(values)
105 .filter(v -> (v.i % 2) == 0)
106 .forEach(System.out::println);
107 }
108
109 @Test
110 public void testNullRestrictedType() {
111 Arrays.stream(values)
112 .map(Value::point)
113 .filter(p -> p.x >= 5)
114 .forEach(System.out::println);
115
116 }
117
118 @Test
119 public void testNullableValueType() {
120 Arrays.stream(values)
121 .map(Value::nullablePoint)
122 .filter(p -> p != null)
123 .forEach(System.out::println);
124 }
125
126 @Test
127 public void mapToInt() {
128 Stream<Point> stream = Arrays.stream(values)
129 .filter(v -> (v.getI() % 2) == 0)
130 .map(Value::point);
131 stream.forEach(p -> assertTrue((p.x % 2) == 0));
132 }
133
134 @Test
135 public void testListOfValues() {
136 long count = Arrays.stream(values)
137 .map(Value::list)
138 .flatMap(List::stream)
139 .map(X::x)
140 .filter(x -> x >= 10)
141 .count();
142 assertEquals(count, values.length-1);
143 }
144 }