1/*
2 * Copyright (c) 2015, 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.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package jdk.internal.loader;
27
28import java.lang.module.Configuration;
29import java.lang.module.ResolvedModule;
30import java.util.HashMap;
31import java.util.List;
32import java.util.Map;
33import java.util.stream.Stream;
34
35/**
36 * A pool of class loaders.
37 *
38 * @see ModuleLayer#defineModulesWithManyLoaders
39 */
40
41public final class LoaderPool {
42
43    // maps module names to class loaders
44    private final Map<String, Loader> loaders;
45
46
47    /**
48     * Creates a pool of class loaders. Each module in the given configuration
49     * will be loaded its own class loader in the pool. The class loader is
50     * created with the given parent class loader as its parent.
51     */
52    public LoaderPool(Configuration cf,
53                      List<ModuleLayer> parentLayers,
54                      ClassLoader parentLoader)
55    {
56        Map<String, Loader> loaders = new HashMap<>();
57        for (ResolvedModule resolvedModule : cf.modules()) {
58            Loader loader = new Loader(resolvedModule, this, parentLoader);
59            String mn = resolvedModule.name();
60            loaders.put(mn, loader);
61        }
62        this.loaders = loaders;
63
64        // complete the initialization
65        loaders.values().forEach(l -> l.initRemotePackageMap(cf, parentLayers));
66    }
67
68
69    /**
70     * Returns the class loader for the named module
71     */
72    public Loader loaderFor(String name) {
73        Loader loader = loaders.get(name);
74        assert loader != null;
75        return loader;
76    }
77
78    /**
79     * Returns a stream of the loaders in this pool.
80     */
81    public Stream<Loader> loaders() {
82        return loaders.values().stream();
83    }
84
85}
86
87