MDAC 2.5 SDK - ADO

Supports Method Example (VJ++)

See Also

This example uses the Supports method to display the options supported by a recordset opened with different cursor types. The DisplaySupport function is required for this example to run.

import com.ms.wfc.data.*;
import java.io.*;

public class SupportsX
{
   // The main entry point of the application.

   public static void main (String[] args)
   {
      SupportsX();
      System.exit(0);
   }
   // SupportsX Function

   static void SupportsX()
   {
      // Define ADO Objects.
      Recordset rstTitles = null;

      // Declarations.
      int[] aintCursorType = new int[4];
      String strCnn;
      int intIndex;
      BufferedReader in = 
         new BufferedReader(new InputStreamReader(System.in));

      try
      {
         // Open connections.
         strCnn = "Provider= sqloledb;Data Source=srv;"+
                "Initial Catalog=Pubs;User Id=sa;Password=;";

         // Fill array with CursorType constants.
         aintCursorType[0] = AdoEnums.CursorType.FORWARDONLY;
         aintCursorType[1] = AdoEnums.CursorType.KEYSET;
         aintCursorType[2] = AdoEnums.CursorType.DYNAMIC;
         aintCursorType[3] = AdoEnums.CursorType.STATIC;

         // Open recordset using each CursorType and
         // Optimistic Locking.  Then call the DisplaySupport
         // procedure to display the supported options.
         for(intIndex = 0; intIndex < 4; intIndex++)
         {
            rstTitles = new Recordset();
            rstTitles.setCursorType(aintCursorType[intIndex]);
            rstTitles.setLockType(AdoEnums.LockType.OPTIMISTIC);
            rstTitles.open("Titles", strCnn, aintCursorType[intIndex], 
               AdoEnums.LockType.OPTIMISTIC, AdoEnums.CommandType.TABLE);

            switch(aintCursorType[intIndex])
            {
            case AdoEnums.CursorType.FORWARDONLY:
               System.out.println("ForwardOnly cursor supports:");
               break;
            case AdoEnums.CursorType.KEYSET:
               System.out.println("Keyset cursor supports:");
               break;
            case AdoEnums.CursorType.DYNAMIC:
               System.out.println("Dynamic cursor supports:");
               break;
            case AdoEnums.CursorType.STATIC:
               System.out.println("Static cursor supports:");
               break;
            default:
               break;
            }
            DisplaySupport(rstTitles);
            rstTitles.close();
            System.out.println("Press <Enter> to continue..");
            in.readLine();
         }
      }
      catch(AdoException ae)
      {
         // Notify user of any errors that result from ADO.

         // As passing a Recordset, check for null pointer first.
         if (rstTitles!= null)
         {
            PrintProviderError(rstTitles.getActiveConnection());
         }
         else
         {
            System.out.println("Exception: " + ae.getMessage());
         }
      }
      // System read requires this catch.
      catch( java.io.IOException je)
      {
         PrintIOError(je);
      }
   }
   // DisplaySupport Function

   static void DisplaySupport( Recordset rstTemp )
   {
      long[] alngConstants = new long[11];
      boolean booSupports;
      int intIndex;
      try
      {
         // Fill array with cursor option constants.
         alngConstants[0]  = AdoEnums.CursorOption.ADDNEW;
         alngConstants[1]  = AdoEnums.CursorOption.APPROXPOSITION;
         alngConstants[2]  = AdoEnums.CursorOption.BOOKMARK;
         alngConstants[3]  = AdoEnums.CursorOption.DELETE;
         alngConstants[4]  = AdoEnums.CursorOption.FIND;
         alngConstants[5]  = AdoEnums.CursorOption.HOLDRECORDS;
         alngConstants[6]  = AdoEnums.CursorOption.MOVEPREVIOUS;
         alngConstants[7]  = AdoEnums.CursorOption.NOTIFY;
         alngConstants[8]  = AdoEnums.CursorOption.RESYNC;
         alngConstants[9]  = AdoEnums.CursorOption.UPDATE;
         alngConstants[10] = AdoEnums.CursorOption.UPDATEBATCH;

         for(intIndex = 0; intIndex <= 10; intIndex++)
         {
            booSupports = rstTemp.supports((int)alngConstants[intIndex]);
            if (booSupports)
            {
               switch((int)alngConstants[intIndex])
               {
               case AdoEnums.CursorOption.ADDNEW:
                     System.out.println("    AddNew");
                     break;
               case AdoEnums.CursorOption.APPROXPOSITION:
                     System.out.println(
                        "    AbsolutePosition and AbsolutePage");
                     break;
               case AdoEnums.CursorOption.BOOKMARK:
                     System.out.println("    Bookmark");
                     break;
               case AdoEnums.CursorOption.DELETE:
                     System.out.println("    Delete");
                     break;
               case AdoEnums.CursorOption.FIND:
                     System.out.println("    Find");
                     break;
               case AdoEnums.CursorOption.HOLDRECORDS:
                     System.out.println("    Holding Records");
                     break;
               case AdoEnums.CursorOption.MOVEPREVIOUS:
                     System.out.println("    MovePrevious and Move");
                     break;
               case AdoEnums.CursorOption.NOTIFY:
                     System.out.println("    Notifications");
                     break;
               case AdoEnums.CursorOption.RESYNC:
                     System.out.println("    Resyncing Data");
                     break;
               case AdoEnums.CursorOption.UPDATE:
                     System.out.println("    Update");
                     break;
               case AdoEnums.CursorOption.UPDATEBATCH:
                     System.out.println("    Batch Updating");
                     break;
               default:
                     break;
               }
            }
         }
      }
      catch(AdoException ae)
      {
         // Notify user of any errors that result from ADO.

         // As passing a Recordset, check for null pointer first.
         if (rstTemp!= null)
         {
            PrintProviderError(rstTemp.getActiveConnection());
         }
         else
         {
            System.out.println("Exception: " + ae.getMessage());
         }
      }
   }

   // PrintProviderError Function
   static void PrintProviderError(Connection cnn1)
   {
      // Print Provider Errors from Connection Object.
      // ErrItem is an item object in the Connection’s Errors Collection.
      com.ms.wfc.data.Error               ErrItem = null;
      long                                 nCount = 0;
      int                                       i = 0;

      nCount = cnn1.getErrors().getCount();

      // If there are any errors in the collection, print them.
      if ( nCount > 0)
      {
         // Collection ranges from 0 to nCount-1.
         for ( i=0;i<nCount; i++)
         {
            ErrItem = cnn1.getErrors().getItem(i);
            System.out.println("\t Error Number: " + ErrItem.getNumber() 
               + "\t" + ErrItem.getDescription());
         }
      }
   }
   // PrintIOError Function
   static void PrintIOError(java.io.IOException je)
   {
      System.out.println("Error: \n");
      System.out.println("\t Source: " + je.getClass() + "\n");
      System.out.println("\t Description: "+ je.getMessage() + "\n");
   }
}