Building the Client

• Client should consume as few server resources as possible, for as short a time as is reasonable.
• Don't host connections to a server you are not using. Set that remote reference to null as soon as possible.
• Validate arguments on the client side whenever possible. Increase response time. Reduce server load.
• Most of the client is usually GUI code.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.rmi.*;

public class BankClient {
  public static void main(String[] args) {
    (new BankClientFrame()).show();
  }
}

public class BankClientFrame extends ExitingFrame {
  private JTextField _accountNameField;
  private JTextField _balanceTextField;
  private JTextField _withdrawalTextField;
  private JTextField _depositTextField;
  private Account _account;

  protected void buildGUI() {
    JPanel contentPane = new JPanel(new BorderLayout());

    contentPane.add(buildActionPanel(), BorderLayout.CENTER);
    contentPane.add(buildBalancePanel(), BorderLayout.SOUTH);
    setContentPane(contentPane);
    setSize(250, 100);
  }

  private void resetBalanceField() {
    try {
      Money balance = _account.getBalance();

      _balanceTextField.setText("Balance: " + balance.toString());
    } catch (Exception e) {
      System.out.println("Error occurred while getting account balance\n" + e);
    }
  }

  private JPanel buildActionPanel() {
    JPanel actionPanel = new JPanel(new GridLayout(3, 3));

    actionPanel.add(new JLabel("Account Name:"));
    _accountNameField = new JTextField();
    actionPanel.add(_accountNameField);
    JButton getBalanceButton = new JButton("Get Balance");

    getBalanceButton.addActionListener(new GetBalanceAction());
    actionPanel.add(getBalanceButton);
    actionPanel.add(new JLabel("Withdraw"));
    _withdrawalTextField = new JTextField();
    actionPanel.add(_withdrawalTextField);
    JButton withdrawalButton = new JButton("Do it");

    withdrawalButton.addActionListener(new WithdrawAction());
    actionPanel.add(withdrawalButton);
    actionPanel.add(new JLabel("Deposit"));
    _depositTextField = new JTextField();
    actionPanel.add(_depositTextField);
    JButton depositButton = new JButton("Do it");

    depositButton.addActionListener(new DepositAction());
    actionPanel.add(depositButton);
    return actionPanel;
  }

  private JPanel buildBalancePanel() {
    JPanel balancePanel = new JPanel(new GridLayout(1, 2));

    balancePanel.add(new JLabel("Current Balance:"));
    _balanceTextField = new JTextField();
    _balanceTextField.setEnabled(false);
    balancePanel.add(_balanceTextField);
    return balancePanel;
  }

  private void getAccount() {
    try {
      _account = (Account) Naming.lookup(_accountNameField.getText());
    } catch (Exception e) {
      System.out.println("Couldn't find account. Error was \n " + e);
      e.printStackTrace();
    }
    return;
  }

  private void releaseAccount() {
    _account = null;
  }

  private Money readTextField(JTextField moneyField) {
    try {
      Float floatValue = new Float(moneyField.getText());
      float actualValue = floatValue.floatValue();
      int cents = (int) (actualValue * 100);

      return new PositiveMoney(cents);
    } catch (Exception e) {
      System.out.println("Field doesn't contain a valid value");
    }
    return null;
  }

  private class GetBalanceAction implements ActionListener {
    public void actionPerformed(ActionEvent event) {
      try {
        getAccount();
        resetBalanceField();
        releaseAccount();
      } catch (Exception exception) {
        System.out.println("Couldn't talk to account. Error was \n " + exception);
        exception.printStackTrace();
      }
    }
  }


  private class WithdrawAction implements ActionListener {
    public void actionPerformed(ActionEvent event) {
      try {
        getAccount();
        Money withdrawalAmount = readTextField(_withdrawalTextField);

        _account.makeWithdrawal(withdrawalAmount);
        _withdrawalTextField.setText("");
        resetBalanceField();
        releaseAccount();
      } catch (Exception exception) {
        System.out.println("Couldn't talk to account. Error was \n " + exception);
        exception.printStackTrace();
      }
    }
  }


  private class DepositAction implements ActionListener {
    public void actionPerformed(ActionEvent event) {
      try {
        getAccount();
        Money depositAmount = readTextField(_depositTextField);

        _account.makeDeposit(depositAmount);
        _depositTextField.setText("");
        resetBalanceField();
        releaseAccount();
      } catch (Exception exception) {
        System.out.println("Couldn't talk to account. Error was \n " + exception);
        exception.printStackTrace();
      }
    }
  }
}