Basic.java revision 16177:89ef4b822745 
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
26import java.io.*;
27import java.util.*;
28
29
30public class Basic {
31
32    private static PrintStream out = System.err;
33
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
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
50        TestLoader(String name) { this.name = name; }
51
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
73    public static void main(String[] args) {
74        for (TestLoader tl : Arrays.asList(tcclLoader, systemClLoader, nullClLoader)) {
75            test(tl);
76        }
77    }
78
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