1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
/*
* Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 8020968
* @summary Sanity test for Function wildcard signature
* @run main WalkFunction
*/
import java.lang.StackWalker.StackFrame;
import java.util.Optional;
import java.util.function.Function;
import java.util.stream.Stream;
public class WalkFunction {
private static final StackWalker walker = StackWalker.getInstance();
public static void main(String... args) throws Exception {
testFunctions();
testWildcards();
walker.walk(counter());
walker.walk(wildCounter());
}
private static void testFunctions() {
walker.walk(Stream::count);
try {
walker.walk(null);
throw new RuntimeException("NPE expected");
} catch (NullPointerException e) {}
Optional<StackFrame> result = walker.walk(WalkFunction::reduce);
if (!result.get().getClassName().equals(WalkFunction.class.getName())) {
throw new RuntimeException(result.get() + " expected: " + WalkFunction.class.getName());
}
}
static Optional<StackFrame> reduce(Stream<StackFrame> stream) {
return stream.reduce((r,f) -> r.getClassName().compareTo(f.getClassName()) > 0 ? f : r);
}
private static void testWildcards() {
Function<? super Stream<? extends StackFrame>, Void> f1 = WalkFunction::function;
Function<? super Stream<? super StackFrame>, Void> f2 = WalkFunction::function;
Function<? super Stream<StackFrame>, Void> f3 = WalkFunction::function;
Function<Stream<? extends StackFrame>, Void> f4 = WalkFunction::function;
Function<Stream<? super StackFrame>, Void> f5 = WalkFunction::function;
Function<Stream<StackFrame>, Void> f6 = WalkFunction::function;
walker.walk(f1);
walker.walk(f2);
walker.walk(f3);
walker.walk(f4);
walker.walk(f5);
walker.walk(f6);
}
private static Void function(Stream<?> s) {
return null;
}
private static Function<Stream<?>, Long> wildCounter() {
return Stream::count;
}
private static <T> Function<Stream<T>, Long> counter() {
return Stream::count;
}
}
|
