1 /*
2 * Copyright 2017 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include "sdk/android/native_api/jni/class_loader.h"
12
13 #include <algorithm>
14 #include <string>
15
16 #include "rtc_base/checks.h"
17 #include "sdk/android/generated_native_api_jni/WebRtcClassLoader_jni.h"
18 #include "sdk/android/native_api/jni/java_types.h"
19 #include "sdk/android/native_api/jni/scoped_java_ref.h"
20
21 // Abort the process if |jni| has a Java exception pending. This macros uses the
22 // comma operator to execute ExceptionDescribe and ExceptionClear ignoring their
23 // return values and sending "" to the error stream.
24 #define CHECK_EXCEPTION(jni) \
25 RTC_CHECK(!jni->ExceptionCheck()) \
26 << (jni->ExceptionDescribe(), jni->ExceptionClear(), "")
27
28 namespace webrtc {
29
30 namespace {
31
32 class ClassLoader {
33 public:
ClassLoader(JNIEnv * env)34 explicit ClassLoader(JNIEnv* env)
35 : class_loader_(jni::Java_WebRtcClassLoader_getClassLoader(env)) {
36 class_loader_class_ = reinterpret_cast<jclass>(
37 env->NewGlobalRef(env->FindClass("java/lang/ClassLoader")));
38 CHECK_EXCEPTION(env);
39 load_class_method_ =
40 env->GetMethodID(class_loader_class_, "loadClass",
41 "(Ljava/lang/String;)Ljava/lang/Class;");
42 CHECK_EXCEPTION(env);
43 }
44
FindClass(JNIEnv * env,const char * c_name)45 ScopedJavaLocalRef<jclass> FindClass(JNIEnv* env, const char* c_name) {
46 // ClassLoader.loadClass expects a classname with components separated by
47 // dots instead of the slashes that JNIEnv::FindClass expects.
48 std::string name(c_name);
49 std::replace(name.begin(), name.end(), '/', '.');
50 ScopedJavaLocalRef<jstring> j_name = NativeToJavaString(env, name);
51 const jclass clazz = static_cast<jclass>(env->CallObjectMethod(
52 class_loader_.obj(), load_class_method_, j_name.obj()));
53 CHECK_EXCEPTION(env);
54 return ScopedJavaLocalRef<jclass>(env, clazz);
55 }
56
57 private:
58 ScopedJavaGlobalRef<jobject> class_loader_;
59 jclass class_loader_class_;
60 jmethodID load_class_method_;
61 };
62
63 static ClassLoader* g_class_loader = nullptr;
64
65 } // namespace
66
InitClassLoader(JNIEnv * env)67 void InitClassLoader(JNIEnv* env) {
68 RTC_CHECK(g_class_loader == nullptr);
69 g_class_loader = new ClassLoader(env);
70 }
71
GetClass(JNIEnv * env,const char * name)72 ScopedJavaLocalRef<jclass> GetClass(JNIEnv* env, const char* name) {
73 // The class loader will be null in the JNI code called from the ClassLoader
74 // ctor when we are bootstrapping ourself.
75 return (g_class_loader == nullptr)
76 ? ScopedJavaLocalRef<jclass>(env, env->FindClass(name))
77 : g_class_loader->FindClass(env, name);
78 }
79
80 } // namespace webrtc
81