TermApp/app/src/main/cpp/TerminalDevice.cpp

#include "TerminalDevice.h"
#include <dlfcn.h>
#include "Camera.h"

typedef jbyteArray (*TakePhotoFunc)(int, int, int, int);

bool GetJniEnv(JavaVM *vm, JNIEnv **env)
{
    bool did_attach_thread = false;
    *env = nullptr;
    // Check if the current thread is attached to the VM
    auto get_env_result = vm->GetEnv((void**)env, JNI_VERSION_1_6);
    if (get_env_result == JNI_EDETACHED)
    {
        if (vm->AttachCurrentThread(env, NULL) == JNI_OK) {
            did_attach_thread = true;
        } else {
            // Failed to attach thread. Throw an exception if you want to.
        }
    } else if (get_env_result == JNI_EVERSION)
    {
        // Unsupported JNI version. Throw an exception if you want to.
    }
    return did_attach_thread;
}


CTerminalDevice::CTerminalDevice(JavaVM* vm, jobject service)
{
    m_vm = vm;
    JNIEnv* env = NULL;
    bool attached = GetJniEnv(m_vm, &env);
    m_javaService = env->NewGlobalRef(service);
    if (attached)
    {
        vm->DetachCurrentThread();
    }
}

CTerminalDevice::~CTerminalDevice()
{
    JNIEnv* env = NULL;
    bool attached = GetJniEnv(m_vm, &env);
    env->DeleteGlobalRef(m_javaService);
    if (attached)
    {
        m_vm->DetachCurrentThread();
    }
    m_javaService = NULL;
}

bool CTerminalDevice::TakePhoto(unsigned char channel, unsigned char preset, const string& path, bool photo)
{
    jboolean res = JNI_FALSE;

    CCamera camera;
    camera.initCamera(NULL);
    if (camera.isCameraReady())
    {
        camera.takePicture();
    }

    camera.closeCamera();

#if 0
    JNIEnv* env = NULL;
    bool attached = GetJniEnv(m_vm, &env);
    jclass serviceClass = env->GetObjectClass(m_javaService);
    jmethodID mid = env->GetMethodID(serviceClass, "takePhoto", "(SSLjava/lang/String;)Z");
    jstring str = env->NewStringUTF(path.c_str());
    res = env->CallBooleanMethod (m_javaService, mid, (jint)channel, (jint)preset, str);
    env->ReleaseStringUTFChars(str, path.c_str());
    env->DeleteLocalRef(serviceClass);

    if (!res)
    {
        int aa = 1;
    }
    if (attached)
    {
        m_vm->DetachCurrentThread();
    }
#endif

	return res == JNI_TRUE;
}