RedCore/cocos2d/cocos/platform/android/jni/JniHelper.cpp

/****************************************************************************
Copyright (c) 2010-2012 cocos2d-x.org
Copyright (c) 2013-2017 Chukong Technologies Inc.

http://www.cocos2d-x.org

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
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The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
****************************************************************************/
#include "platform/android/jni/JniHelper.h"
#include <android/log.h>
#include <string.h>
#include <pthread.h>

#include "base/ccUTF8.h"

#define  LOG_TAG    "JniHelper"
#define  LOGD(...)  __android_log_print(ANDROID_LOG_DEBUG,LOG_TAG,__VA_ARGS__)
#define  LOGE(...)  __android_log_print(ANDROID_LOG_ERROR,LOG_TAG,__VA_ARGS__)

static pthread_key_t g_key;

jclass _getClassID(const char *className) {
    if (nullptr == className) {
        return nullptr;
    }

    JNIEnv* env = cocos2d::JniHelper::getEnv();

    jstring _jstrClassName = env->NewStringUTF(className);

    jclass _clazz = (jclass) env->CallObjectMethod(cocos2d::JniHelper::classloader,
                                                   cocos2d::JniHelper::loadclassMethod_methodID,
                                                   _jstrClassName);

    if (nullptr == _clazz) {
        LOGE("Classloader failed to find class of %s", className);
        env->ExceptionClear();
    }

    env->DeleteLocalRef(_jstrClassName);
        
    return _clazz;
}

void _detachCurrentThread(void* a) {
    cocos2d::JniHelper::getJavaVM()->DetachCurrentThread();
}

namespace cocos2d {

    JavaVM* JniHelper::_psJavaVM = nullptr;
    jmethodID JniHelper::loadclassMethod_methodID = nullptr;
    jobject JniHelper::classloader = nullptr;
    std::function<void()> JniHelper::classloaderCallback = nullptr;
    
    jobject JniHelper::_activity = nullptr;
    std::unordered_map<JNIEnv*, std::vector<jobject>> JniHelper::localRefs;

    JavaVM* JniHelper::getJavaVM() {
        pthread_t thisthread = pthread_self();
        LOGD("JniHelper::getJavaVM(), pthread_self() = %ld", thisthread);
        return _psJavaVM;
    }

    void JniHelper::setJavaVM(JavaVM *javaVM) {
        pthread_t thisthread = pthread_self();
        LOGD("JniHelper::setJavaVM(%p), pthread_self() = %ld", javaVM, thisthread);
        _psJavaVM = javaVM;

        pthread_key_create(&g_key, _detachCurrentThread);
    }

    JNIEnv* JniHelper::cacheEnv(JavaVM* jvm) {
        JNIEnv* _env = nullptr;
        // get jni environment
        jint ret = jvm->GetEnv((void**)&_env, JNI_VERSION_1_4);
        
        switch (ret) {
        case JNI_OK :
            // Success!
            pthread_setspecific(g_key, _env);
            return _env;
                
        case JNI_EDETACHED :
            // Thread not attached
            if (jvm->AttachCurrentThread(&_env, nullptr) < 0)
                {
                    LOGE("Failed to get the environment using AttachCurrentThread()");

                    return nullptr;
                } else {
                // Success : Attached and obtained JNIEnv!
                pthread_setspecific(g_key, _env);
                return _env;
            }
                
        case JNI_EVERSION :
            // Cannot recover from this error
            LOGE("JNI interface version 1.4 not supported");
        default :
            LOGE("Failed to get the environment using GetEnv()");
            return nullptr;
        }
    }

    JNIEnv* JniHelper::getEnv() {
        JNIEnv *_env = (JNIEnv *)pthread_getspecific(g_key);
        if (_env == nullptr)
            _env = JniHelper::cacheEnv(_psJavaVM);
        return _env;
    }
    
    jobject JniHelper::getActivity() {
        return _activity;
    }

    bool JniHelper::setClassLoaderFrom(jobject activityinstance) {
        JniMethodInfo _getclassloaderMethod;
        if (!JniHelper::getMethodInfo_DefaultClassLoader(_getclassloaderMethod,
                                                         "android/content/Context",
                                                         "getClassLoader",
                                                         "()Ljava/lang/ClassLoader;")) {
            return false;
        }

        jobject _c = cocos2d::JniHelper::getEnv()->CallObjectMethod(activityinstance,
                                                                    _getclassloaderMethod.methodID);

        if (nullptr == _c) {
            return false;
        }

        JniMethodInfo _m;
        if (!JniHelper::getMethodInfo_DefaultClassLoader(_m,
                                                         "java/lang/ClassLoader",
                                                         "loadClass",
                                                         "(Ljava/lang/String;)Ljava/lang/Class;")) {
            return false;
        }

        JniHelper::classloader = cocos2d::JniHelper::getEnv()->NewGlobalRef(_c);
        JniHelper::loadclassMethod_methodID = _m.methodID;
        JniHelper::_activity = cocos2d::JniHelper::getEnv()->NewGlobalRef(activityinstance);
        if (JniHelper::classloaderCallback != nullptr){
            JniHelper::classloaderCallback();
        }

        return true;
    }

    bool JniHelper::getStaticMethodInfo(JniMethodInfo &methodinfo,
                                        const char *className, 
                                        const char *methodName,
                                        const char *paramCode) {
        if ((nullptr == className) ||
            (nullptr == methodName) ||
            (nullptr == paramCode)) {
            return false;
        }

        JNIEnv *env = JniHelper::getEnv();
        if (!env) {
            LOGE("Failed to get JNIEnv");
            return false;
        }
            
        jclass classID = _getClassID(className);
        if (! classID) {
            LOGE("Failed to find class %s", className);
            env->ExceptionClear();
            return false;
        }

        jmethodID methodID = env->GetStaticMethodID(classID, methodName, paramCode);
        if (! methodID) {
            LOGE("Failed to find static method id of %s", methodName);
            env->ExceptionClear();
            return false;
        }
            
        methodinfo.classID = classID;
        methodinfo.env = env;
        methodinfo.methodID = methodID;
        return true;
    }

    bool JniHelper::getMethodInfo_DefaultClassLoader(JniMethodInfo &methodinfo,
                                                     const char *className,
                                                     const char *methodName,
                                                     const char *paramCode) {
        if ((nullptr == className) ||
            (nullptr == methodName) ||
            (nullptr == paramCode)) {
            return false;
        }

        JNIEnv *env = JniHelper::getEnv();
        if (!env) {
            return false;
        }

        jclass classID = env->FindClass(className);
        if (! classID) {
            LOGE("Failed to find class %s", className);
            env->ExceptionClear();
            return false;
        }

        jmethodID methodID = env->GetMethodID(classID, methodName, paramCode);
        if (! methodID) {
            LOGE("Failed to find method id of %s", methodName);
            env->ExceptionClear();
            return false;
        }

        methodinfo.classID = classID;
        methodinfo.env = env;
        methodinfo.methodID = methodID;

        return true;
    }

    bool JniHelper::getMethodInfo(JniMethodInfo &methodinfo,
                                  const char *className,
                                  const char *methodName,
                                  const char *paramCode) {
        if ((nullptr == className) ||
            (nullptr == methodName) ||
            (nullptr == paramCode)) {
            return false;
        }

        JNIEnv *env = JniHelper::getEnv();
        if (!env) {
            return false;
        }

        jclass classID = _getClassID(className);
        if (! classID) {
            LOGE("Failed to find class %s", className);
            env->ExceptionClear();
            return false;
        }

        jmethodID methodID = env->GetMethodID(classID, methodName, paramCode);
        if (! methodID) {
            LOGE("Failed to find method id of %s", methodName);
            env->ExceptionClear();
            return false;
        }

        methodinfo.classID = classID;
        methodinfo.env = env;
        methodinfo.methodID = methodID;

        return true;
    }

    std::string JniHelper::jstring2string(jstring jstr) {
        if (jstr == nullptr) {
            return "";
        }
        
        JNIEnv *env = JniHelper::getEnv();
        if (!env) {
            return "";
        }

        std::string strValue = cocos2d::StringUtils::getStringUTFCharsJNI(env, jstr);

        return strValue;
    }

    jstring JniHelper::convert(cocos2d::JniMethodInfo& t, const char* x) {
        jstring ret = cocos2d::StringUtils::newStringUTFJNI(t.env, x ? x : "");
        localRefs[t.env].push_back(ret);
        return ret;
    }

    jstring JniHelper::convert(cocos2d::JniMethodInfo& t, const std::string& x) {
        return convert(t, x.c_str());
    }

    void JniHelper::deleteLocalRefs(JNIEnv* env) {
        if (!env) {
            return;
        }

        for (const auto& ref : localRefs[env]) {
            env->DeleteLocalRef(ref);
        }
        localRefs[env].clear();
    }

    void JniHelper::reportError(const std::string& className, const std::string& methodName, const std::string& signature) {
        LOGE("Failed to find static java method. Class name: %s, method name: %s, signature: %s ",  className.c_str(), methodName.c_str(), signature.c_str());
    }

} //namespace cocos2d