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      1 /*
      2  * Copyright (C) 2014 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 #ifndef CORE_JNI_HELPERS
     18 #define CORE_JNI_HELPERS
     19 
     20 #include "JNIHelp.h"
     21 #include <android_runtime/AndroidRuntime.h>
     22 
     23 namespace android {
     24 
     25 // Defines some helpful functions.
     26 
     27 static inline jclass FindClassOrDie(JNIEnv* env, const char* class_name) {
     28     jclass clazz = env->FindClass(class_name);
     29     LOG_ALWAYS_FATAL_IF(clazz == NULL, "Unable to find class %s", class_name);
     30     return clazz;
     31 }
     32 
     33 static inline jfieldID GetFieldIDOrDie(JNIEnv* env, jclass clazz, const char* field_name,
     34                                        const char* field_signature) {
     35     jfieldID res = env->GetFieldID(clazz, field_name, field_signature);
     36     LOG_ALWAYS_FATAL_IF(res == NULL, "Unable to find static field %s", field_name);
     37     return res;
     38 }
     39 
     40 static inline jmethodID GetMethodIDOrDie(JNIEnv* env, jclass clazz, const char* method_name,
     41                                          const char* method_signature) {
     42     jmethodID res = env->GetMethodID(clazz, method_name, method_signature);
     43     LOG_ALWAYS_FATAL_IF(res == NULL, "Unable to find method %s", method_name);
     44     return res;
     45 }
     46 
     47 static inline jfieldID GetStaticFieldIDOrDie(JNIEnv* env, jclass clazz, const char* field_name,
     48                                              const char* field_signature) {
     49     jfieldID res = env->GetStaticFieldID(clazz, field_name, field_signature);
     50     LOG_ALWAYS_FATAL_IF(res == NULL, "Unable to find static field %s", field_name);
     51     return res;
     52 }
     53 
     54 static inline jmethodID GetStaticMethodIDOrDie(JNIEnv* env, jclass clazz, const char* method_name,
     55                                                const char* method_signature) {
     56     jmethodID res = env->GetStaticMethodID(clazz, method_name, method_signature);
     57     LOG_ALWAYS_FATAL_IF(res == NULL, "Unable to find static method %s", method_name);
     58     return res;
     59 }
     60 
     61 template <typename T>
     62 static inline T MakeGlobalRefOrDie(JNIEnv* env, T in) {
     63     jobject res = env->NewGlobalRef(in);
     64     LOG_ALWAYS_FATAL_IF(res == NULL, "Unable to create global reference.");
     65     return static_cast<T>(res);
     66 }
     67 
     68 static inline int RegisterMethodsOrDie(JNIEnv* env, const char* className,
     69                                        const JNINativeMethod* gMethods, int numMethods) {
     70     int res = AndroidRuntime::registerNativeMethods(env, className, gMethods, numMethods);
     71     LOG_ALWAYS_FATAL_IF(res < 0, "Unable to register native methods.");
     72     return res;
     73 }
     74 
     75 }  // namespace android
     76 
     77 #endif  // CORE_JNI_HELPERS
     78