1/*
2 * Copyright (c) 2015, 2017, 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.module;
27
28import java.lang.module.Configuration;
29import java.lang.module.ResolvedModule;
30import java.util.HashMap;
31import java.util.HashSet;
32import java.util.Map;
33import java.util.Set;
34import java.util.function.Function;
35
36import jdk.internal.loader.ClassLoaders;
37
38
39/**
40 * Supports the mapping of modules to class loaders. The set of modules mapped
41 * to the boot and platform class loaders is generated at build time from
42 * this source file.
43 */
44public final class ModuleLoaderMap {
45
46    /**
47     * Maps the system modules to the built-in class loaders.
48     */
49    public static final class Mapper implements Function<String, ClassLoader> {
50        private final Map<String, ClassLoader> map;
51
52        Mapper(Map<String, ClassLoader> map) {
53            this.map = map; // defensive copy not needed
54        }
55
56        @Override
57        public ClassLoader apply(String name) {
58            return map.get(name);
59        }
60    }
61
62    /**
63     * Returns the names of the modules defined to the boot loader.
64     */
65    public static Set<String> bootModules() {
66        // The list of boot modules generated at build time.
67        String[] BOOT_MODULES = new String[] { "@@BOOT_MODULE_NAMES@@" };
68        Set<String> bootModules = new HashSet<>(BOOT_MODULES.length);
69        for (String mn : BOOT_MODULES) {
70            bootModules.add(mn);
71        }
72        return bootModules;
73    }
74
75    /**
76     * Returns the names of the modules defined to the platform loader.
77     */
78    public static Set<String> platformModules() {
79        // The list of platform modules generated at build time.
80        String[] PLATFORM_MODULES = new String[] { "@@PLATFORM_MODULE_NAMES@@" };
81        Set<String> platformModules = new HashSet<>(PLATFORM_MODULES.length);
82        for (String mn : PLATFORM_MODULES) {
83            platformModules.add(mn);
84        }
85        return platformModules;
86    }
87
88    /**
89     * Returns the function to map modules in the given configuration to the
90     * built-in class loaders.
91     */
92    static Function<String, ClassLoader> mappingFunction(Configuration cf) {
93        Set<String> bootModules = bootModules();
94        Set<String> platformModules = platformModules();
95
96        ClassLoader platformClassLoader = ClassLoaders.platformClassLoader();
97        ClassLoader appClassLoader = ClassLoaders.appClassLoader();
98
99        Map<String, ClassLoader> map = new HashMap<>();
100        for (ResolvedModule resolvedModule : cf.modules()) {
101            String mn = resolvedModule.name();
102            if (!bootModules.contains(mn)) {
103                if (platformModules.contains(mn)) {
104                    map.put(mn, platformClassLoader);
105                } else {
106                    map.put(mn, appClassLoader);
107                }
108            }
109        }
110        return new Mapper(map);
111    }
112}
113