Pass Arguments By Reference

Question

Hello Everyone,
I have this problem the native method that I want call from my JAva program accepts a long value by reference. How do I pass it from my Java code. Here is the JAva code:
long ulRecSize;
bRet = this.GetRecordingSizePtr(szEventName, ulRecSize,1);
and here is the C++ native method:
BOOL GetRecordingSize(char* pszEventFileName, unsigned long* pulRecSize, unsigned char ucDevice)
/* ALL NOT Required code is omitted*/
HeaderSize = sizeof(Recording) - sizeof(RecordedFrame);     // size of recording header
VehicleDataSize = recSpec.numDEIDs * sizeof(DE_RetVal);     // size of Vehicle Data (1 frame)
RecordedFrameSize = VehicleDataSize + sizeof(unsigned long);     // size of RecordedFrame
VehRecordingSize = RecordedFrameSize * eventData.wNumOfFrames;// size of VehRecording (all frames)
*pulRecSize = HeaderSize + VehRecordingSize;     // total size
NOW ulRecSiz is supposed to be passed by reference which becomes *pulRecSize
Any help?????

Answer 1

I am assuming that you want to pass the long via refrence so that when the C code changes it the java value has also been changed
I don't think it is possible to pass a reference to a primative such as long with the JNI. Java doesn't allow you to get a reference to a primitive. I think you will have place the long inside a wrapper class that contains a long which allows you to set and get that long value. Then pass that class as an object and use the get and set methods to change the long value inside.
But I could be wrong.
Hello Everyone,
I have this problem the native method that I want call
from my JAva program accepts a long value by
reference. How do I pass it from my Java code. Here is
the JAva code:
long ulRecSize;
bRet = this.GetRecordingSizePtr(szEventName,
ulRecSize,1);
and here is the C++ native method:
BOOL GetRecordingSize(char* pszEventFileName, unsigned
long* pulRecSize, unsigned char ucDevice)
/* ALL NOT Required code is omitted*/
HeaderSize = sizeof(Recording) -
sizeof(RecordedFrame);     // size of recording header
VehicleDataSize = recSpec.numDEIDs *
sizeof(DE_RetVal);     // size of Vehicle Data (1 frame)
RecordedFrameSize = VehicleDataSize + sizeof(unsigned
long);     // size of RecordedFrame
VehRecordingSize = RecordedFrameSize *
eventData.wNumOfFrames;// size of VehRecording (all
frames)
*pulRecSize = HeaderSize + VehRecordingSize;     // total
size
NOW ulRecSiz is supposed to be passed by reference
which becomes *pulRecSize
Any help?????