1 /**
2  * Copyright (C) 2017 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 _ANDROID_JAVA_REF_H
18 #define _ANDROID_JAVA_REF_H
19 
20 #include <android-base/macros.h>
21 #include <functional>
22 #include <jni.h>
23 #include <memory>
24 #include <type_traits>
25 
26 namespace android {
27 
28 template <typename T>
29 using JavaRef = std::unique_ptr<typename std::remove_pointer<T>::type, std::function<void(T)>>;
30 
31 template <typename T>
make_javaref(JNIEnv * env,T ref)32 JavaRef<T> make_javaref(JNIEnv *env, T ref) {
33     return JavaRef<T>(ref, [env](T ref) {
34         if (env && ref) {
35             env->DeleteLocalRef(ref);
36         }
37     });
38 }
39 
40 JavaRef<jstring> make_javastr(JNIEnv *env, const std::string &str);
41 
42 } // namespace android
43 
44 #endif // _ANDROID_JAVA_REF_H
45