1 /*
2 * Copyright (c) 2020, 2025, 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.NullRestricted;
32 import jdk.internal.vm.annotation.Strict;
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 static value class Point {
54 public int x;
55 public int y;
56 Point(int x, int y) {
57 this.x = x;
58 this.y = y;
59 }
60 }
61
62 static value class Value {
63 int i;
64 @NullRestricted @Strict
65 Point p;
66 Point nullable;
67 List<X> list;
68 Value(int i, Point/* Point! */ p, Point np, List<X> list) {
69 this.i = i;
70 this.p = p;
71 this.nullable = np;
72 this.list = list;
73 }
74
75 Point point() {
76 return p;
77 }
78
79 Point nullablePoint() {
80 return nullable;
81 }
82
83 int getI() { return i; }
84
85 List<X> list() { return list; }
86 }
87
88 final Value[] values = init();
89 private Value[] init() {
90 Value[] values = new Value[10];
91 for (int i = 0; i < 10; i++) {
92 values[i] = new Value(i,
93 new Point(i,i*2),
94 (i%2) == 0 ? null : new Point(i*10, i*20),
95 List.of(new X(i), new X(i*10)));
96 }
97 return values;
98 }
99
100 @Test
101 public void testValues() {
102 Arrays.stream(values)
103 .filter(v -> (v.i % 2) == 0)
104 .forEach(System.out::println);
105 }
106
107 @Test
108 public void testNullRestrictedType() {
109 Arrays.stream(values)
110 .map(Value::point)
111 .filter(p -> p.x >= 5)
112 .forEach(System.out::println);
113
114 }
115
116 @Test
117 public void testNullableValueType() {
118 Arrays.stream(values)
119 .map(Value::nullablePoint)
120 .filter(p -> p != null)
121 .forEach(System.out::println);
122 }
123
124 @Test
125 public void mapToInt() {
126 Stream<Point> stream = Arrays.stream(values)
127 .filter(v -> (v.getI() % 2) == 0)
128 .map(Value::point);
129 stream.forEach(p -> assertTrue((p.x % 2) == 0));
130 }
131
132 @Test
133 public void testListOfValues() {
134 long count = Arrays.stream(values)
135 .map(Value::list)
136 .flatMap(List::stream)
137 .map(X::x)
138 .filter(x -> x >= 10)
139 .count();
140 assertEquals(count, values.length-1);
141 }
142 }