1/*
2 * Copyright (C) 2006 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.app;
18
19import dalvik.system.PathClassLoader;
20
21import java.util.HashMap;
22import java.util.Map;
23
24class ApplicationLoaders
25{
26    public static ApplicationLoaders getDefault()
27    {
28        return gApplicationLoaders;
29    }
30
31    public ClassLoader getClassLoader(String zip, String libPath, ClassLoader parent)
32    {
33        /*
34         * This is the parent we use if they pass "null" in.  In theory
35         * this should be the "system" class loader; in practice we
36         * don't use that and can happily (and more efficiently) use the
37         * bootstrap class loader.
38         */
39        ClassLoader baseParent = ClassLoader.getSystemClassLoader().getParent();
40
41        synchronized (mLoaders) {
42            if (parent == null) {
43                parent = baseParent;
44            }
45
46            /*
47             * If we're one step up from the base class loader, find
48             * something in our cache.  Otherwise, we create a whole
49             * new ClassLoader for the zip archive.
50             */
51            if (parent == baseParent) {
52                ClassLoader loader = mLoaders.get(zip);
53                if (loader != null) {
54                    return loader;
55                }
56
57                PathClassLoader pathClassloader =
58                    new PathClassLoader(zip, libPath, parent);
59
60                mLoaders.put(zip, pathClassloader);
61                return pathClassloader;
62            }
63
64            return new PathClassLoader(zip, parent);
65        }
66    }
67
68    private final Map<String, ClassLoader> mLoaders = new HashMap<String, ClassLoader>();
69
70    private static final ApplicationLoaders gApplicationLoaders
71        = new ApplicationLoaders();
72}
73