UglyMoneyTransferService

UglyMoneyTransferService

public class UglyMoneyTransferService 
{
	public void transferFunds(Account source, Account target, BigDecimal amount, boolean allowDuplicateTxn) throws IllegalArgumentException, RuntimeException {	
	Connection conn = null;
	try {
		conn = DBUtils.getConnection();
		PreparedStatement pstmt = conn.prepareStatement("Select * from accounts where acno = ?");
		pstmt.setString(1, source.getAcno());
		ResultSet rs = pstmt.executeQuery();
		Account sourceAccount = null;
		if(rs.next()) {
			sourceAccount = new Account();
			//populate account properties from ResultSet
		}
		if(sourceAccount == null){
			throw new IllegalArgumentException("Invalid Source ACNO");
		}
		Account targetAccount = null;
		pstmt.setString(1, target.getAcno());
		rs = pstmt.executeQuery();
		if(rs.next()) {
			targetAccount = new Account();
			//populate account properties from ResultSet
		}
		if(targetAccount == null){
			throw new IllegalArgumentException("Invalid Target ACNO");
		}
		if(!sourceAccount.isOverdraftAllowed()) {
			if((sourceAccount.getBalance() - amount) < 0) {
				throw new RuntimeException("Insufficient Balance");
			}
		}
		else {
			if(((sourceAccount.getBalance()+sourceAccount.getOverdraftLimit()) - amount) < 0) {
				throw new RuntimeException("Insufficient Balance, Exceeding Overdraft Limit");
			}
		}
		AccountTransaction lastTxn = .. ; //JDBC code to obtain last transaction of sourceAccount
		if(lastTxn != null) {
			if(lastTxn.getTargetAcno().equals(targetAccount.getAcno()) && lastTxn.getAmount() == amount && !allowDuplicateTxn) {
			throw new RuntimeException("Duplicate transaction exception");//ask for confirmation and proceed
			}
		}
		sourceAccount.debit(amount);
		targetAccount.credit(amount);
		TransactionService.saveTransaction(source, target,  amount);
	}
	catch(Exception e){
		logger.error("",e);
	}
	finally {
		try { 
			conn.close(); 
		} 
		catch(Exception e){ 
			//Not everything is in your control..sometimes we have to believe in GOD/JamesGosling and proceed
		}
	}
}	
}