1 /*
2 * Copyright (C) 2008 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 #include "java_lang_VMClassLoader.h"
18
19 #include "class_linker.h"
20 #include "jni_internal.h"
21 #include "mirror/class_loader.h"
22 #include "mirror/object-inl.h"
23 #include "scoped_fast_native_object_access.h"
24 #include "ScopedUtfChars.h"
25 #include "zip_archive.h"
26
27 namespace art {
28
VMClassLoader_findLoadedClass(JNIEnv * env,jclass,jobject javaLoader,jstring javaName)29 static jclass VMClassLoader_findLoadedClass(JNIEnv* env, jclass, jobject javaLoader,
30 jstring javaName) {
31 ScopedFastNativeObjectAccess soa(env);
32 mirror::ClassLoader* loader = soa.Decode<mirror::ClassLoader*>(javaLoader);
33 ScopedUtfChars name(env, javaName);
34 if (name.c_str() == nullptr) {
35 return nullptr;
36 }
37 ClassLinker* cl = Runtime::Current()->GetClassLinker();
38 std::string descriptor(DotToDescriptor(name.c_str()));
39 const size_t descriptor_hash = ComputeModifiedUtf8Hash(descriptor.c_str());
40 mirror::Class* c = cl->LookupClass(soa.Self(), descriptor.c_str(), descriptor_hash, loader);
41 if (c != nullptr && c->IsResolved()) {
42 return soa.AddLocalReference<jclass>(c);
43 }
44 if (loader != nullptr) {
45 // Try the common case.
46 StackHandleScope<1> hs(soa.Self());
47 cl->FindClassInPathClassLoader(soa, soa.Self(), descriptor.c_str(), descriptor_hash,
48 hs.NewHandle(loader), &c);
49 if (c != nullptr) {
50 return soa.AddLocalReference<jclass>(c);
51 }
52 }
53 // Class wasn't resolved so it may be erroneous or not yet ready, force the caller to go into
54 // the regular loadClass code.
55 return nullptr;
56 }
57
VMClassLoader_getBootClassPathSize(JNIEnv *,jclass)58 static jint VMClassLoader_getBootClassPathSize(JNIEnv*, jclass) {
59 return Runtime::Current()->GetClassLinker()->GetBootClassPath().size();
60 }
61
62 /*
63 * Returns a string URL for a resource with the specified 'javaName' in
64 * entry 'index' of the boot class path.
65 *
66 * We return a newly-allocated String in the following form:
67 *
68 * jar:file://path!/name
69 *
70 * Where "path" is the bootstrap class path entry and "name" is the string
71 * passed into this method. "path" needs to be an absolute path (starting
72 * with '/'); if it's not we'd need to make it absolute as part of forming
73 * the URL string.
74 */
VMClassLoader_getBootClassPathResource(JNIEnv * env,jclass,jstring javaName,jint index)75 static jstring VMClassLoader_getBootClassPathResource(JNIEnv* env, jclass, jstring javaName,
76 jint index) {
77 ScopedUtfChars name(env, javaName);
78 if (name.c_str() == nullptr) {
79 return nullptr;
80 }
81
82 const std::vector<const DexFile*>& path =
83 Runtime::Current()->GetClassLinker()->GetBootClassPath();
84 if (index < 0 || size_t(index) >= path.size()) {
85 return nullptr;
86 }
87 const DexFile* dex_file = path[index];
88
89 // For multidex locations, e.g., x.jar:classes2.dex, we want to look into x.jar.
90 const std::string& location(dex_file->GetBaseLocation());
91
92 std::string error_msg;
93 std::unique_ptr<ZipArchive> zip_archive(ZipArchive::Open(location.c_str(), &error_msg));
94 if (zip_archive.get() == nullptr) {
95 LOG(WARNING) << "Failed to open zip archive '" << location << "': " << error_msg;
96 return nullptr;
97 }
98 std::unique_ptr<ZipEntry> zip_entry(zip_archive->Find(name.c_str(), &error_msg));
99 if (zip_entry.get() == nullptr) {
100 return nullptr;
101 }
102
103 std::string url;
104 StringAppendF(&url, "jar:file://%s!/%s", location.c_str(), name.c_str());
105 return env->NewStringUTF(url.c_str());
106 }
107
108 static JNINativeMethod gMethods[] = {
109 NATIVE_METHOD(VMClassLoader, findLoadedClass, "!(Ljava/lang/ClassLoader;Ljava/lang/String;)Ljava/lang/Class;"),
110 NATIVE_METHOD(VMClassLoader, getBootClassPathResource, "(Ljava/lang/String;I)Ljava/lang/String;"),
111 NATIVE_METHOD(VMClassLoader, getBootClassPathSize, "!()I"),
112 };
113
register_java_lang_VMClassLoader(JNIEnv * env)114 void register_java_lang_VMClassLoader(JNIEnv* env) {
115 REGISTER_NATIVE_METHODS("java/lang/VMClassLoader");
116 }
117
118 } // namespace art
119