I am developing a web application using jsf, spring and hibernate. This application is
similar to other web sites like money.rediff.com and finance.yahoo.com. Our company has
made a deal with a realtime data provider. He provided a exe file
which on installing generates a dll file, pdf listing the methods of dll file and other
license documents.
I used dependency walker and found that the methods are decorated with some symbols. I am trying to call the methods of dll file with the help of JNA in the following way.
Here are my codes,
DllImplementation .java
public interface CLibrary extends StdCallLibrary
{
CLibrary INSTANCE = (CLibrary) Native.loadLibrary("DeskApi", CLibrary.class, new
HashMap() {{
put("Initialise", "?
Initialise@CDeskApi@@QAEHPADPAVCDeskApiCallback@@@Z");
put("GetQuote","?GetQuote@CDeskApi@@QAEHPADHKK@Z");
put("DeleteQuote","?DeleteQuote@CDeskApi@@QAEHPADH@Z");
put("VersionInfo","?VersionInfo@CDeskApi@@QAEHPAD@Z");
//Other functions
}});
public int Initialise(String serialkey,CDeskApiCallback callBack);
public int GetQuote(String symbol, int periodicity, long lasttimeupdate, long
echo);
public int DeleteQuote(String symbol, int periodicity);
public int VersionInfo(String versionOut);
}
public static void main(String argv[]) {
try{
CDeskApiCallback callback = new CDeskApiCallback();
String key = "fsg@xxxxxxxxxxxxxxxxxxxxd24";
int retValue = CLibrary.INSTANCE.Initialise(key,callback);
System.out.println("Initialise () ="+retValue);
} catch (UnsatisfiedLinkError e) {
e.printStackTrace();
}
}
}
CDeskApiCallback.java
public class CDeskApiCallback {
public native int realtime_notify(String symbol, Pointer recent);
public native int quote_notify( String symbol, int interval, int nMaxSize,
Pointer quotes, long echo);
}
Quotation.java
public class Quotation extends Structure implements Structure.ByReference{
public NativeLong DateTime; // 8 byte
public float Price;
public float Open;
public float High;
public float Low;
public float Volume;
public float OpenInterest;
public Quotation(){
super();
System.out.println("in Quotation()");
read();
}
}
RecentInfo.java
public class RecentInfo extends Structure implements Structure.ByReference{
public float fOpen;
public float fHigh;
public float fLow;
public float fLast;
public float fTradeVol;
public float fTotalVol;
public float fOpenInt;
public float fPrev;
public float fBid;
public float fAsk;
public int iBidSize;
public int iAskSize;
public NativeLong DateTime;
public RecentInfo(){
super();
read();
}
}
To test the code when I execute the main method I am getting a -1 as a integer return value. From the pdf of software providers it indicates as an error. How can i implement the callback mechanism.
I am new to JNA feature . Any clue or help will be highly appreciable.
Edit:
@manuell
First of all thanks for the help. I made the changes as advised but no use. I am pasting the header file given by the software provider. Please suggest...
#pragma once
//version 0.0 Beta 1
#define DAILY_PERIOD 24*60
#define MIN_PERIOD 1
#ifdef API_DLL
#define METHOD_TYPE __declspec(dllexport)
#else
#define METHOD_TYPE __declspec(dllimport)
#endif
//data is provided in the struct below
struct Quotation {
unsigned long DateTime; // 8 byte
float Price;
float Open;
float High;
float Low;
float Volume;
float OpenInterest;
};
struct RecentInfo
{
float fOpen;
float fHigh;
float fLow;
float fLast;
float fTradeVol;
float fTotalVol;
float fOpenInt;
float fPrev;
float fBid;
int iBidSize;
float fAsk;
int iAskSize;
unsigned long DateTime; // 8 byte
};
//callback class which is to be implemented by the client application
class METHOD_TYPE CDeskApiCallback
{
public:
/*
Description : Tick Update from the server for symbol requested
Parameters : 1. symbol of interest
2. Data, please note value -1 indicates no update.
Return : 0 in case of success and -1 in case of error
*/
virtual int realtime_notify(const char* symbol, RecentInfo *pRecent)=0;
/*
Description : Vwap Update from the server for symbol requested
Parameters : 1. symbol of interest
2. update of interval requested
3. data size
4. data
5. user message
Return : 0 in case of success and -1 in case of error
*/
virtual int quote_notify( const char* symbol, int interval, int nMaxSize, Quotation *pQuotes, unsigned long echo)=0;
};
//this is the control class from which requests are initiated.
class METHOD_TYPE CDeskApi
{
public:
CDeskApi(void);
/*
Description : Initiates a connection to NEST system
Parameters : 1. serialkey provided to implement the api
2. object of CDeskApiCallback implemented
Return : 0 in case of success and -1 in case of error
*/
int Initialise(char *serialkey, CDeskApiCallback* callback);
/*
Description : Request data from the server
Parameters : 1. symbol of interest
2. intervals of 1 min, multiples of 1 min, DAILY_PERIOD in case of daily.
3. data to be retrieved from. in no of seconds since epoch
4. identifier, which is returned in the callback
Return : 0 in case of success and -1 in case of error
*/
int GetQuote(char * symbol, int periodicity, unsigned long lasttimeupdate, unsigned long echo);
/*
Description : Delete a Prior Request to the server
Parameters : 1. symbol of interest
2. interval, send -1 to delete all requested information of the symbol
Return : 0 in case of success and -1 in case of error
*/
int DeleteQuote(char * symbol, int periodicity);
/*
Description : Delete a Prior Request to the server
Parameters : 1. symbol of interest
2. interval, send -1 to delete all requested information of the symbol
Return : 0 in case of success and -1 in case of error
*/
int VersionInfo(char * versionout);
~CDeskApi(void);
};
