State Property Example (VJ++)

This example uses the State property to display a message while asynchronous connections are opening and asynchronous commands are executing.

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

public class StateX
{
   // The main entry point of the application.
   public static void main (String[] args)
   {
      StateX();
      System.exit(0);
   }
   // StateX Function
   static void StateX()
   {
      // Define ADO Objects.
      Connection cnn1 = null;
      Connection cnn2 = null;
      Command cmdChange = null;
      Command cmdRestore = null;

      // Declarations.
      String strCnn = "Provider='sqloledb';Data Source='MySqlServer';"+
                  "Initial Catalog='Pubs';Integrated Security='SSPI';";
      BufferedReader in = 
         new BufferedReader(new InputStreamReader(System.in));

      try
      {
         // Open two Asynchronous connections, displaying
         // a message while connecting.
         cnn1 = new Connection();
         cnn2 = new Connection();

         cnn1.open(strCnn,"","",AdoEnums.ConnectOption.ASYNCCONNECT);
         while(cnn1.getState()==AdoEnums.ObjectState.CONNECTING)
            System.out.println("Opening the first connection....");

         cnn2.open(strCnn,"","",AdoEnums.ConnectOption.ASYNCCONNECT);
         while(cnn2.getState()==AdoEnums.ObjectState.CONNECTING)
            System.out.println("Opening the second connection....");

         // Create two command Objects.
         cmdChange = new Command();
         cmdChange.setActiveConnection(cnn1);
         cmdChange.setCommandText("UPDATE Titles SET type = 'self_help'"+
                            "WHERE type = 'psychology'");

         cmdRestore = new Command();
         cmdRestore.setActiveConnection(cnn2);
         cmdRestore.setCommandText(
            "UPDATE Titles SET type = 'psychology'"+
            "WHERE type = 'self_help'");

         // Executing the commands, displaying a message
         // while they are executing.
         cmdChange.execute(null,AdoEnums.ExecuteOption.ASYNCEXECUTE);

         while(cmdChange.getState() == AdoEnums.ObjectState.EXECUTING)
            System.out.println("Change command executing....");

         cmdRestore.execute(null,AdoEnums.ExecuteOption.ASYNCEXECUTE);

         while(cmdRestore.getState() == AdoEnums.ObjectState.EXECUTING)
            System.out.println("Restore command executing....");

         System.out.println("Press <Enter> to continue..");
         in.readLine();
      }
      // System read requires this catch.
      catch(java.io.IOException je)
      {
         PrintIOError(je);
      }
      catch(AdoException ae)
      {
         // Notify user of any errors resulting from ADO.

         // As passing a connection, check for null pointer first.
         if(cnn1 != null)
         {
            System.out.println("The error has occured in cnn1:");
            PrintProviderError(cnn1);
         }
         else if(cnn2 != null)
         {
            System.out.println("The error has occured in cnn2:");
            PrintProviderError(cnn2);
         }
         else
         {
            System.out.println("Exception: "+ ae.getMessage());
         }
      }   
      
      finally
      {
         // Cleanup objects before exit.   
         if (cnn1 != null)
            if (cnn1.getState() == 1)
               cnn1.close();  
         if (cnn2 != null)
            if (cnn2.getState() == 1)
               cnn2.close();
      }

   }
   // PrintProviderError Function
   static void PrintProviderError(Connection cnn1)
   {
      // Print Provider Errors from Connection Object.
      // ErrItem is an item object in the Connections 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");
   }
}
// EndStateJ

See Also

State Property