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                 String entryUri = new File(bootClassPathEntry).toURI().toString();
46 
47                 // We assume all entries are zip or jar files.
48                 URLStreamHandler urlStreamHandler =
49                         new ClassPathURLStreamHandler(bootClassPathEntry);
50                 urlStreamHandlers.add(urlStreamHandler);
51             } catch (IOException e) {
52                 // Skip it
53                 System.logE("Unable to open boot classpath entry: " + bootClassPathEntry, e);
54             }
55         }
56         return urlStreamHandlers.toArray(new ClassPathURLStreamHandler[urlStreamHandlers.size()]);
57     }
58 
59     /**
60      * Get a resource from a file in the bootstrap class path.
61      *
62      * We assume that the bootclasspath can't change once the VM has started.
63      * This assumption seems to be supported by the spec.
64      */
getResource(String name)65     static URL getResource(String name) {
66         for (ClassPathURLStreamHandler urlHandler : bootClassPathUrlHandlers) {
67             URL url = urlHandler.getEntryUrlOrNull(name);
68             if (url != null) {
69                 return url;
70             }
71         }
72         return null;
73     }
74 
75     /*
76      * Get an enumeration with all matching resources.
77      */
getResources(String name)78     static List<URL> getResources(String name) {
79         ArrayList<URL> list = new ArrayList<URL>();
80         for (ClassPathURLStreamHandler urlHandler : bootClassPathUrlHandlers) {
81             URL url = urlHandler.getEntryUrlOrNull(name);
82             if (url != null) {
83                 list.add(url);
84             }
85         }
86         return list;
87     }
88 
89     @FastNative
findLoadedClass(ClassLoader cl, String name)90     native static Class findLoadedClass(ClassLoader cl, String name);
91 
92     /**
93      * Boot class path manipulation, for getResources().
94      */
getBootClassPathEntries()95     native private static String[] getBootClassPathEntries();
96 
97 }
98