Java Reference
In-Depth Information
Example 17−5: RemoteDBBankServer.java (continued)
db.commit();
}
catch (SQLException e) {
try { db.rollback(); } catch (Exception e2) {}
throw new BankingException("SQLException: " + e.getMessage() +
": " + e.getSQLState());
}
finally { try { s.close(); } catch (Exception e) {} }
}
/** Withdraw the specified amount from the named account */
public synchronized FunnyMoney withdraw(String name, String password,
int amount)
throws RemoteException, BankingException
{
int balance = 0;
Statement s = null;
try {
balance = verify(name, password);
if (balance < amount)
throw new BankingException("Insufficient Funds");
s = db.createStatement();
// Update the account balance
s.executeUpdate("UPDATE accounts " +
"SET balance = " + (balance - amount) + " " +
"WHERE name='" + name + "' " +
" AND password = '" + password + "'");
// Add a row to the transaction history
s.executeUpdate("INSERT INTO " + name + "_history " +
"VALUES ('Withdrew " + amount +
" at " + new Date() + "')");
db.commit();
}
catch (SQLException e) {
try { db.rollback(); } catch (Exception e2) {}
throw new BankingException("SQLException: " + e.getMessage() +
": " + e.getSQLState());
}
finally { try { s.close(); } catch (Exception e) {} }
return new FunnyMoney(amount);
}
/** Return the balance of the specified account */
public synchronized int getBalance(String name, String password)
throws RemoteException, BankingException
{
int balance;
try {
// Get the balance
balance = verify(name, password);
// Commit the transaction
db.commit();
}
catch (SQLException e) {
try { db.rollback(); } catch (Exception e2) {}
throw new BankingException("SQLException: " + e.getMessage() +
": " + e.getSQLState());
