// Illustrate Transaction handling without container support.
// This is example is from Java Server Programming J2EE Edition
// by Wrox Press Ltd.

// This client's second dataset leaves behind an inconsistent 
// table.

import java.sql.Connection;
import java.sql.DriverManager;

public class Client1 {


    // The Access database located at D:\McCarthy\www\95-702\JDBCTransaction\AccountDB
    // has a table called Account and a DNS name of AccountDNS

    // The value in the amount field must be >= 0 and <= 15000.

    // The first transfer should work fine.

    /*
    private static final String ACCOUNT1 = "A32-116";
    private static final String NAME1 = "Lynne Older";
    private static final double AMOUNT1 = 10000.0;

    private static final String ACCOUNT2 = "A32-117";
    private static final String NAME2= "Pat Mahar";
    private static final double AMOUNT2 = 12000.0;

    private static final double TRANSFER_AMOUNT = 1000.0;
    */
    

    // This transfer should not work correctly - we lose the money

    private static final String ACCOUNT1 = "B32-116";
    private static final String NAME1= "Cristina Couglin";
    private static final double AMOUNT1 = 10000.0;

    private static final String ACCOUNT2 = "B32-117";
    private static final String NAME2= "Mary Klopot";
    private static final double AMOUNT2 = 14000.0;

    private static final double TRANSFER_AMOUNT = 2000.0;
    


    public static void main(String args[]) throws Exception {

     DriverManager.registerDriver(new sun.jdbc.odbc.JdbcOdbcDriver());

     createAccounts();

     transfer(ACCOUNT1, ACCOUNT2, TRANSFER_AMOUNT);

    }

    private static void createAccounts() {

         Connection con = null;

         try {
                             
               con = DriverManager.getConnection("jdbc:odbc:AccountDSN");
   
               Account account1 = new Account();
               account1.create(ACCOUNT1,NAME1,AMOUNT1,con);

               Account account2 = new Account();
               account2.create(ACCOUNT2,NAME2,AMOUNT2,con);

               System.out.println("Acoounts created");
          }
          catch(Exception e) {
               System.out.println("Exception thrown");
               e.printStackTrace();
          }
          finally {
               try {
                    if(con != null) {
                        con.close();
                    }
               }
               catch(Exception e) { System.out.println("Exception while closing"); } 
          }

    }


    private static void transfer(String accountIDFrom, String accountIDTo, double amount) {

         
               Connection con = null;

               try {

                  con = DriverManager.getConnection("jdbc:odbc:AccountDSN");

                  Account accountFrom = new Account();
                  accountFrom.read(accountIDFrom,con);

                  Account accountTo = new Account();
                  accountTo.read(accountIDTo,con);

                  accountFrom.setAmount(accountFrom.getAmount() - amount);

                  accountTo.setAmount(accountTo.getAmount() + amount);

                  accountFrom.update(con);
                  accountTo.update(con);

                  System.out.println("Funds Transfererred");
               }

               catch(Exception e) {
                  e.printStackTrace();
               }
               finally {
                  try {
                        if(con != null) {
                            con.close();
                        }
                  }
                  catch(Exception e) {
                       System.out.println("Caught exception while closing");
                  }
               }
       }
}