State Property Example (VJ++)

State Property Example (VJ++)

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

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=srv;"+
                        "Initial Catalog = Pubs;User Id = sa; Password=;";
        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....");

            // Cleanup Objects before exit.
            cnn1.close();
            cnn2.close();

            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());
            }
        }

    }
    // 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");
    }
}