#include <string.h>

#include <jni.h>

#include <android/log.h>

#define TAG "HELLO"

#define LOGV(...) __android_log_print(ANDROID_LOG_VERBOSE, TAG, __VA_ARGS__)

#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG , TAG, __VA_ARGS__)

#define LOGI(...) __android_log_print(ANDROID_LOG_INFO , TAG, __VA_ARGS__)

#define LOGW(...) __android_log_print(ANDROID_LOG_WARN , TAG, __VA_ARGS__)

#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR , TAG, __VA_ARGS__)

# define NELEM(x) ((int) (sizeof(x) / sizeof((x)[])))

jstring native_stringFromJNI( JNIEnv* env, jobject thiz )

{

    return (*env)->NewStringUTF(env, "Hello from JNI !");

}

static const char *classPathName = "com/example/hellojni/HelloJni";

static JNINativeMethod methods[] = {

        {"stringFromJNI", "()Ljava/lang/String;", (void*)native_stringFromJNI},

};

jint JNI_OnLoad(JavaVM* vm, void* reserved)

{

    JNIEnv* env = NULL;

    jclass clazz;

    //获取JNI环境对象

    if ((*vm)->GetEnv(vm, (void**) &env, JNI_VERSION_1_4) != JNI_OK) {

        LOGE("ERROR: GetEnv failed\n");

        return JNI_ERR;

    }

    //注册本地方法.Load 目标类

    clazz = (*env)->FindClass(env,classPathName);

    if (clazz == NULL)

    {

        LOGE("Native registration unable to find class '%s'", classPathName);

        return JNI_ERR;

    }

    //注册本地native方法

    if((*env)->RegisterNatives(env, clazz, methods, NELEM(methods)) < )

    {

        LOGE("ERROR: MediaPlayer native registration failed\n");

           return JNI_ERR;

    }

    /* success -- return valid version number */

    return JNI_VERSION_1_4;

}