如果您有共享內存,例如使用CreateFileMapping
(Windows)或shmget
(Unix),則您只需要Java端的本地方法。然後,你可以創建一個ByteBuffer
是直接訪問使用NewDirectByteBuffer
這樣的共享內存:
JNIEXPORT jobject JNICALL Java_getSharedBuffer(JNIEnv* env, jobject caller) {
void* myBuffer;
int bufferLength;
現在,你必須得到一個指針到共享內存。在Windows中,您會使用這樣的:
bufferLength = 1024; // assuming your buffer is 1024 bytes big
HANDLE mem = OpenFileMapping(FILE_MAP_READ, // assuming you only want to read
false, "MyBuffer"); // assuming your file mapping is called "MyBuffer"
myBuffer = MapViewOfFile(mem, FILE_MAP_READ, 0, 0, 0);
// don't forget to do UnmapViewOfFile when you're finished
現在你可以創建一個由這個共享內存支持的ByteBuffer
:
// put it into a ByteBuffer so the java code can use it
return env->NewDirectByteBuffer(myBuffer, bufferLength);
}