【JNI开发】C++调用java函数的实现方法

public class SNaviEngineManager {

public void sendMessage(int msg)
{

}

public static int sendMessage(int msg)
{

}

}

void ms_sendmessage(int msg)
{

// 获取JNI环境
bool attach = false;
int status=0;
JNIEnv* pEnv = NULL;
status = g_jvm->GetEnv((void **) &pEnv, JNI_VERSION_1_6);
if( status < 0 )
{
LOGI("AttachCurrentThread");
g_jvm->AttachCurrentThread(&pEnv, NULL);
attach = true;
}

jmethodID mid = pEnv->GetMethodID( g_jcNaviEngine, "<init>", "()V");
jobject obj = pEnv->NewObject( g_jcNaviEngine, mid);
if (obj == 0)
{
LOGE("Create object failed!");
}

// 调用成员方法
mid = pEnv->GetMethodID( g_jcNaviEngine, "sendMessage", "(I)V");
if (mid != 0)
{
pEnv->CallVoidMethod( obj, mid, msg );
}

// 释放JNI环境
if( attach )
{
g_jvm->DetachCurrentThread();
}
}

void ms_sendmessage(int msg)
{

// 获取JNI环境
bool attach = false;
int status=0;
JNIEnv* pEnv = NULL;
status = g_jvm->GetEnv((void **) &pEnv, JNI_VERSION_1_6);
if( status < 0 )
{
LOGI("AttachCurrentThread");
g_jvm->AttachCurrentThread(&pEnv, NULL);
attach = true;
}

// 调用静态成员方法
jmethodID mid = pEnv->GetStaticMethodID( static_cast<jclass>(g_joNaviEngine), "sendMessage", "(I)V");
if (mid != 0)
{
pEnv->CallStaticVoidMethod( obj, mid, msg );
}

// 释放JNI环境
if( attach )
{
g_jvm->DetachCurrentThread();
}
}

/** 实例化类对象 */
jobject getInstance( JNIEnv* pEnv , jclass classzz )
{
if ( pEnv == NULL )
{
return NULL ;
}

// 获取构造方法
jmethodID constructor = pEnv->GetMethodID(classzz, "<init>", "()V");
if (NULL == constructor)
{
return NULL;
}
// 实例化类对象
return pEnv->NewObject(classzz, constructor);
}