1 /*
2  * Copyright (C) 2007 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 
17 package java.lang;
18 
19 import dalvik.annotation.optimization.FastNative;
20 import java.io.File;
21 import java.io.IOException;
22 import java.net.URL;
23 import java.net.URLStreamHandler;
24 import java.util.ArrayList;
25 import java.util.List;
26 import libcore.io.ClassPathURLStreamHandler;
27 
28 class VMClassLoader {
29 
30     private static final ClassPathURLStreamHandler[] bootClassPathUrlHandlers;
31     static {
32         bootClassPathUrlHandlers = createBootClassPathUrlHandlers();
33     }
34 
35     /**
36      * Creates an array of ClassPathURLStreamHandler objects for handling resource loading from
37      * the boot classpath.
38      */
createBootClassPathUrlHandlers()39     private static ClassPathURLStreamHandler[] createBootClassPathUrlHandlers() {
40         String[] bootClassPathEntries = getBootClassPathEntries();
41         ArrayList<URLStreamHandler> urlStreamHandlers =
42                 new ArrayList<URLStreamHandler>(bootClassPathEntries.length);
43         for (String bootClassPathEntry : bootClassPathEntries) {
44             try {
45                 // We assume all entries are zip or jar files.
46                 URLStreamHandler urlStreamHandler =
47                         new ClassPathURLStreamHandler(bootClassPathEntry);
48                 urlStreamHandlers.add(urlStreamHandler);
49             } catch (IOException e) {
50                 // Skip it
51                 System.logE("Unable to open boot classpath entry: " + bootClassPathEntry, e);
52             }
53         }
54         return urlStreamHandlers.toArray(new ClassPathURLStreamHandler[urlStreamHandlers.size()]);
55     }
56 
57     /**
58      * Get a resource from a file in the bootstrap class path.
59      *
60      * We assume that the bootclasspath can't change once the VM has started.
61      * This assumption seems to be supported by the spec.
62      */
getResource(String name)63     static URL getResource(String name) {
64         for (ClassPathURLStreamHandler urlHandler : bootClassPathUrlHandlers) {
65             URL url = urlHandler.getEntryUrlOrNull(name);
66             if (url != null) {
67                 return url;
68             }
69         }
70         return null;
71     }
72 
73     /*
74      * Get an enumeration with all matching resources.
75      */
getResources(String name)76     static List<URL> getResources(String name) {
77         ArrayList<URL> list = new ArrayList<URL>();
78         for (ClassPathURLStreamHandler urlHandler : bootClassPathUrlHandlers) {
79             URL url = urlHandler.getEntryUrlOrNull(name);
80             if (url != null) {
81                 list.add(url);
82             }
83         }
84         return list;
85     }
86 
87     @FastNative
findLoadedClass(ClassLoader cl, String name)88     native static Class findLoadedClass(ClassLoader cl, String name);
89 
90     /**
91      * Boot class path manipulation, for getResources().
92      */
getBootClassPathEntries()93     native private static String[] getBootClassPathEntries();
94 
95 }
96