VC++ Code to List System DSN in your PC

Had a peculiar problem. I wanted to display the list of DSNs registred in a machine in a Java JComboBox.
As far as I know, Java in no way can get a list of System DSN.So thought of using a JNI program to do this.
Was trying a vc++ program to list out the System DSN List and I ended up writing this small program.
Create a win32 Console application in VC++, include MFC support (for proper working of SQLnnn functions)
Replace the code to your main c++/c file.Click here to Download the Files.
// dsntest2.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include "dsntest2.h" //nothing much in this .h file, created by VC++
					  //file name same as your cpp file
#include 
#include 

#define DSN_BUFFER_LEN 256

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

///////////////////////////////////////
// The one and only application object

CWinApp theApp;

using namespace std;

int _tmain(int argc, TCHAR* argv[], TCHAR* envp[])
{
	int nRetCode = 0;

	// initialize MFC and print and error on failure
	if (!AfxWinInit(::GetModuleHandle(NULL), NULL, ::GetCommandLine(), 0))
	{
		// TODO: change error code to suit your needs
		cerr << _T("Fatal Error: MFC initialization failed") << endl;
		nRetCode = 1;
	}
	else
	{
		//code to find out the system dsn list
		int handle;
		SQLHANDLE  sqlHandle;

		SQLSMALLINT nFirstDSN=SQL_FETCH_FIRST_SYSTEM; //if you want user dsns, assign
													 //SQL_FETCH_FIRST_USER
		SQLSMALLINT nNextDSN =SQL_FETCH_NEXT;

		SQLCHAR sDSName[DSN_BUFFER_LEN]; //dsn name
		SQLCHAR sDrvrDtl[DSN_BUFFER_LEN];//driver info

		SQLSMALLINT nDsnLen,nDtlLen;

		handle = SQLAllocHandle(SQL_HANDLE_ENV,SQL_NULL_HANDLE,&sqlHandle);
		handle = SQLSetEnvAttr(sqlHandle,SQL_ATTR_ODBC_VERSION,(SQLPOINTER)SQL_OV_ODBC3,0);

		if(handle != SQL_SUCCESS){
			cerr<<"Setting of ODBC Version Failed!";
			nRetCode=1;
		}

		handle = SQLDataSources(sqlHandle ,nFirstDSN,sDSName,DSN_BUFFER_LEN,&nDsnLen,sDrvrDtl,DSN_BUFFER_LEN,&nDtlLen);
		cout.setf(ios::left);
		cout << setw(6)<<"DSN: "<< setw(15) << sDSName
			 << setw(5)<<"Driver: "<< sDrvrDtl << endl;

		while(handle == SQL_SUCCESS){
			handle = SQLDataSources(sqlHandle ,nNextDSN,sDSName,DSN_BUFFER_LEN,&nDsnLen,sDrvrDtl,DSN_BUFFER_LEN,&nDtlLen);
			cout << setw(6)<<"DSN: " <<  setw(15) << sDSName
				 << setw(5)<<"Driver: " << sDrvrDtl << endl;

		}

		handle = SQLFreeHandle(SQL_HANDLE_ENV,sqlHandle);

		cout << "\nThese are the system DSNs found in this Petti!\n\n";

		nRetCode = 0;

	}

	return nRetCode;
}