1 /*
2  * Copyright (c) 2005, 2012, 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 
26 import java.io.*;
27 import java.util.*;
28 
29 
30 public class Basic {
31 
32     private static PrintStream out = System.err;
33 
setOf(Iterable<T> it)34     private static <T> Set<T> setOf(Iterable<T> it) {
35         Set<T> s = new HashSet<T>();
36         for (T t : it)
37             s.add(t);
38         return s;
39     }
40 
checkEquals(Set<T> s1, Set<T> s2, boolean eq)41     private static <T> void checkEquals(Set<T> s1, Set<T> s2, boolean eq) {
42         if (s1.equals(s2) != eq)
43             throw new RuntimeException(String.format("%b %s : %s",
44                                                      eq, s1, s2));
45     }
46 
47     abstract static class TestLoader {
48         String name;
49 
TestLoader(String name)50         TestLoader(String name) { this.name = name; }
51 
load()52         abstract ServiceLoader<FooService> load();
53     }
54 
55     static TestLoader tcclLoader = new TestLoader("Thread context class loader") {
56         ServiceLoader<FooService> load() {
57             return ServiceLoader.load(FooService.class);
58         }
59     };
60 
61     static TestLoader systemClLoader = new TestLoader("System class loader") {
62         ServiceLoader<FooService> load() {
63             return ServiceLoader.load(FooService.class, ClassLoader.getSystemClassLoader());
64         }
65     };
66 
67     static TestLoader nullClLoader = new TestLoader("null (defer to system class loader)") {
68         ServiceLoader<FooService> load() {
69             return ServiceLoader.load(FooService.class, null);
70         }
71     };
72 
main(String[] args)73     public static void main(String[] args) {
74         for (TestLoader tl : Arrays.asList(tcclLoader, systemClLoader, nullClLoader)) {
75             test(tl);
76         }
77     }
78 
test(TestLoader tl)79     static void test(TestLoader tl) {
80         ServiceLoader<FooService> sl = tl.load();
81         out.format("%s: %s%n", tl.name, sl);
82 
83         // Providers are cached
84         Set<FooService> ps = setOf(sl);
85         checkEquals(ps, setOf(sl), true);
86 
87         // The cache can be flushed and reloaded
88         sl.reload();
89         checkEquals(ps, setOf(sl), false);
90 
91     }
92 }
93