JCash.iml

@@ -7,5 +7,15 @@
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
+    <orderEntry type="module-library">
+      <library name="JUnit4">
+        <CLASSES>
+          <root url="jar://$MAVEN_REPOSITORY$/junit/junit/4.13.1/junit-4.13.1.jar!/" />
+          <root url="jar://$MAVEN_REPOSITORY$/org/hamcrest/hamcrest-core/1.3/hamcrest-core-1.3.jar!/" />
+        </CLASSES>
+        <JAVADOC />
+        <SOURCES />
+      </library>
+    </orderEntry>
   </component>
 </module>

src/me/teridax/jcash/Main.java

@@ -6,53 +6,79 @@ import me.teridax.jcash.gui.login.LoginController;
 
 import javax.swing.*;
 
-public class Main {
+public final class Main {
 
+    /**
+     * Main instance of this program. Contains the primary window.
+     */
     private static Main instance;
+
+    /**
+     * Primary window of this program
+     */
     private final JFrame window;
 
     private Main() {
-        window = new JFrame();
+        // create main window and set defaults
-        window.setTitle("Bankautomat");
+        this.window = new JFrame();
-        window.setLocationByPlatform(true);
+        this.window.setTitle("Bankautomat");
-        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        this.window.setLocationByPlatform(true);
+        this.window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     }
 
     public static void main(String[] args) {
+        // create main instance and show the login screen
         instance();
-        getInstance().popLoginScreen();
+        getInstance().showLoginScreen();
     }
 
     public static Main getInstance() {
         return instance;
     }
 
+    /**
+     * Attempts to create a new instance of the singleton class Main.
+     * This method throws an exception if the class is already instantiated.
+     * @throws IllegalStateException if the class is already instantiated
+     * @pre the static instance of this class should be null.
+     * @post the static instance of this class will be set
+     */
     public static void instance() {
-        if (instance == null) {
+        if (null != instance)
-            instance = new Main();
+            throw new IllegalStateException(Main.class.getName() + " is already initialized");
-            return;
+
+        Main.instance = new Main();
     }
 
-        throw new IllegalStateException("me.teridax.jcash.Main is already initialized");
+    /**
-    }
+     * Shows the open dialog for selecting a database file. After selection, it then proceeds to prompt login.
-
+     * Afterward the selected account can be managed.
-    public void popLoginScreen() {
+     * This method is non-blocking and all work described is performed asynchronously on the AWT Event dispatcher.
+     */
+    public void showLoginScreen() {
         SwingUtilities.invokeLater(() -> {
+            // select db file
             var path = Loader.load();
+            // read database and login
             var login = new LoginController(path);
 
+            // when we have logged in set the account viewer as window content
             login.addAccountSelectionListener(account -> {
                 var profileCont = new AccountController(account);
-                window.setContentPane(profileCont.getView());
+                this.window.setContentPane(profileCont.getView());
-                window.pack();
+                this.window.pack();
             });
 
-            window.setContentPane(login.getView());
+            // we are not logged in yet, so show the login prompt on the main window
-            window.pack();
+            this.window.setContentPane(login.getView());
-            window.setVisible(true);
+            this.window.pack();
+            this.window.setVisible(true);
         });
     }
 
+    /**
+     * Logs the user out of the database, hiding the main window.
+     */
     public void logout() {
         window.setContentPane(new JLabel("you're logged out"));
         window.setVisible(false);

src/me/teridax/jcash/banking/Account.java

@@ -1,6 +1,6 @@
 package me.teridax.jcash.banking;
 
-import me.teridax.jcash.decode.Decoder;
+import me.teridax.jcash.decode.StringUtils;
 
 import java.util.Objects;
 
@@ -20,17 +20,17 @@ public abstract class Account {
     public static Account fromColumns(String[] columns) {
         Objects.requireNonNull(columns);
 
-        var iban = Decoder.decodeUniqueIdentificationNumber(columns[0]);
+        var iban = StringUtils.decodeUniqueIdentificationNumber(columns[0]);
-        var pin = Decoder.decodeUniqueIdentificationNumber(columns[1]);
+        var pin = StringUtils.decodeUniqueIdentificationNumber(columns[1]);
-        var balance = Decoder.decodeCurrency(columns[2]);
+        var balance = StringUtils.decodeCurrency(columns[2]);
-        var type = Decoder.decodeName(columns[3]);
+        var type = StringUtils.decodeName(columns[3]);
 
         try {
             if (type.equals("Sparkonto")) {
-                var interest = Decoder.decodePercent(columns[4]);
+                var interest = StringUtils.decodePercent(columns[4]);
                 return new SavingsAccount(iban, pin, balance, interest);
             } else if (type.equals("Girokonto")) {
-                var overdraft = Decoder.decodeCurrency(columns[5]);
+                var overdraft = StringUtils.decodeCurrency(columns[5]);
                 return new Girokonto(iban, pin, balance, overdraft);
             } else {
                 throw new IllegalArgumentException("Invalid account type: " + type);

src/me/teridax/jcash/banking/BankingManagementSystem.java

@@ -1,6 +1,6 @@
 package me.teridax.jcash.banking;
 
-import me.teridax.jcash.decode.Decoder;
+import me.teridax.jcash.decode.StringUtils;
 
 import java.io.IOException;
 import java.nio.file.Files;
@@ -34,7 +34,7 @@ public final class BankingManagementSystem {
                 var account = Account.fromColumns(tail(columns, 2));
 
                 var blz = Bank.validateBlz(columns[1]);
-                var name = Decoder.decodeName(columns[0]);
+                var name = StringUtils.decodeName(columns[0]);
                 var bankOfLine = new Bank(blz, name);
 
                 var bankOfSet = bms.banks.stream().filter(b -> b.equals(bankOfLine)).findFirst();

src/me/teridax/jcash/banking/Owner.java

@@ -1,6 +1,6 @@
 package me.teridax.jcash.banking;
 
-import me.teridax.jcash.decode.Decoder;
+import me.teridax.jcash.decode.StringUtils;
 
 import java.util.Objects;
 
@@ -28,12 +28,12 @@ public final class Owner {
         if (columns.length != 6)
             throw new IllegalArgumentException("Invalid number of columns: " + columns.length);
 
-        var uid = Decoder.decodeUniqueIdentificationNumber(columns[0]);
+        var uid = StringUtils.decodeUniqueIdentificationNumber(columns[0]);
-        var familyName = Decoder.decodeName(columns[1]);
+        var familyName = StringUtils.decodeName(columns[1]);
-        var name = Decoder.decodeName(columns[2]);
+        var name = StringUtils.decodeName(columns[2]);
-        var street = Decoder.decodeStreet(columns[3]);
+        var street = StringUtils.decodeStreet(columns[3]);
-        var zip = Decoder.decodeUniqueIdentificationNumber(columns[4]);
+        var zip = StringUtils.decodeUniqueIdentificationNumber(columns[4]);
-        var city = Decoder.decodeName(columns[5]);
+        var city = StringUtils.decodeName(columns[5]);
 
         return new Owner(uid, familyName, name, zip, city, street);
     }

src/me/teridax/jcash/banking/Tests.java

@@ -4,7 +4,7 @@ import org.junit.Test;
 
 import java.nio.file.Paths;
 
-public class Testing {
+public class Tests {
 
     @Test
     public void test() {

src/me/teridax/jcash/decode/StringUtils.java

@@ -10,11 +10,29 @@ import java.util.regex.Pattern;
 
 import static junit.framework.TestCase.assertEquals;
 
-public class Decoder {
+/**
+ * Utility class for converting various single line strings into a specific data type according
+ * to a format mostly dictated by a locale.
+ */
+public class StringUtils {
 
+    /**
+     * Locale to use when converting strings
+     */
     private static final Locale LOCALE = Locale.GERMANY;
+    /**
+     * NumberFormat to use when converting strings
+     */
     public static final NumberFormat LOCAL_NUMBER_FORMAT = NumberFormat.getInstance(LOCALE);
 
+    /**
+     * Attempts to convert the given string into a double value representing a percentage.
+     * The percentage is stored in the range [0,1] and can linearly be mapped to [0, 100] by multiplying with 100.
+     * @param number the string to convert
+     * @return the double value
+     * @throws IllegalArgumentException when the format is invalid
+     * @throws NullPointerException when the argument is null
+     */
     public static double decodePercent(String number) throws IllegalArgumentException, NullPointerException {
         Objects.requireNonNull(number);
 
@@ -28,6 +46,13 @@ public class Decoder {
         }
     }
 
+    /**
+     * Attempts to convert the given string into a currency value.
+     * @param currency the string to convert
+     * @return the double value
+     * @throws IllegalArgumentException when the format is invalid
+     * @throws NullPointerException when the argument is null
+     */
     public static double decodeCurrency(String currency) throws IllegalArgumentException, NullPointerException {
         Objects.requireNonNull(currency);
 
@@ -38,6 +63,14 @@ public class Decoder {
         }
     }
 
+    /**
+     * Attempts to convert the given string into universally unique number.
+     * This function does not check for duplicates. The number must be a positive integer.
+     * @param number the string to convert
+     * @return the integer serial number
+     * @throws IllegalArgumentException when the format is invalid
+     * @throws NullPointerException when the argument is null
+     */
     public static int decodeUniqueIdentificationNumber(String number) throws IllegalArgumentException, NullPointerException {
         Objects.requireNonNull(number);
 
@@ -56,6 +89,14 @@ public class Decoder {
         }
     }
 
+    /**
+     * Attempts to convert the given string into a name.
+     * This method performs validation and trimming.
+     * @param name the string to convert
+     * @return the qualified name
+     * @throws IllegalArgumentException when the format is invalid
+     * @throws NullPointerException when the argument is null
+     */
     public static String decodeName(String name) throws IllegalArgumentException, NullPointerException {
         Objects.requireNonNull(name);
 
@@ -70,6 +111,13 @@ public class Decoder {
         }
     }
 
+    /**
+     * Attempts to convert the given string into a street and an optional house address.
+     * @param street the string to convert
+     * @return the address name
+     * @throws IllegalArgumentException when the format is invalid
+     * @throws NullPointerException when the argument is null
+     */
     public static String decodeStreet(String street) throws IllegalArgumentException, NullPointerException {
         Objects.requireNonNull(street);
 

src/me/teridax/jcash/gui/Loader.java

@@ -6,10 +6,26 @@ import javax.swing.*;
 import javax.swing.filechooser.FileNameExtensionFilter;
 import java.io.File;
 
+import static javax.swing.JFileChooser.APPROVE_OPTION;
+
+/**
+ * Utility class for loading a BMS configuration from a csv file.
+ */
 public class Loader {
 
+    /**
+     * Filter that only allows for files with *.csv extension
+     */
     private static final FileNameExtensionFilter FILE_FILTER = new FileNameExtensionFilter("Comma separated value spreadsheet", "csv", "CSV");
 
+    private Loader() {}
+
+    /**
+     * Load a BMS from a csv file. Opens up a dialog which prompts the user to select a single file.
+     * Once the file is selected this function will try to parse the contents to a BMS and return the instance.
+     * @return a valid BMS instance loaded from a file
+     * @throws IllegalStateException When either no file is selected or the selected files content is invalid
+     */
     public static BankingManagementSystem load() throws IllegalStateException {
         var fileChooser = new JFileChooser();
         fileChooser.setMultiSelectionEnabled(false);
@@ -19,7 +35,8 @@ public class Loader {
         fileChooser.setAcceptAllFileFilterUsed(false);
         fileChooser.setCurrentDirectory(new File("/home/teridax/IdeaProjects/JCash/res"));
 
-        if (fileChooser.showDialog(null, "Load database") == JFileChooser.APPROVE_OPTION) {
+        if (fileChooser.showDialog(null, "Load database") == APPROVE_OPTION) {
+            // parse file content
             try {
                 return BankingManagementSystem.loadFromCsv(fileChooser.getSelectedFile().toPath());
             } catch (Exception e) {

src/me/teridax/jcash/gui/account/AccountController.java

@@ -26,7 +26,7 @@ public class AccountController {
 
         this.view.getLogout().addActionListener(e -> {
             Main.getInstance().logout();
-            Main.getInstance().popLoginScreen();
+            Main.getInstance().showLoginScreen();
         });
 
         this.view.getDeposit().addActionListener(e -> {

src/me/teridax/jcash/gui/account/AccountView.java

@@ -1,7 +1,7 @@
 package me.teridax.jcash.gui.account;
 
 import me.teridax.jcash.banking.*;
-import me.teridax.jcash.decode.Decoder;
+import me.teridax.jcash.decode.StringUtils;
 
 import javax.swing.*;
 import java.awt.*;
@@ -22,7 +22,6 @@ public class AccountView extends JPanel {
     private JComboBox<String> accountSelection;
 
     private JPanel content;
-    private JPanel buttonPanel;
 
     private JButton logout;
     private JButton transfer;
@@ -48,12 +47,12 @@ public class AccountView extends JPanel {
         this.name.setText(owner.getName() + " " + owner.getFamilyName());
         this.address.setText(owner.getStreet() + " " + owner.getCity());
 
-        this.balance.setText(Decoder.LOCAL_NUMBER_FORMAT.format(account.getBalance()) + " €");
+        this.balance.setText(StringUtils.LOCAL_NUMBER_FORMAT.format(account.getBalance()) + " €");
 
         this.type.setText(account.getClass().getSimpleName());
         if (account instanceof Girokonto) {
             this.typeSpecialLabel.setText("Überziehungsbetrag");
-            this.typeSpecialProperty.setText( Decoder.LOCAL_NUMBER_FORMAT.format(((Girokonto) account).getOverdraft()) + " €");
+            this.typeSpecialProperty.setText( StringUtils.LOCAL_NUMBER_FORMAT.format(((Girokonto) account).getOverdraft()) + " €");
         } else if (account instanceof SavingsAccount) {
             this.typeSpecialLabel.setText("Zinsbetrag");
             this.typeSpecialProperty.setText( ((SavingsAccount) account).getInterest() + " %" );
@@ -70,7 +69,6 @@ public class AccountView extends JPanel {
     private void createLayout() {
         setLayout(new BorderLayout(16, 16));
         add(new JScrollPane(content), BorderLayout.CENTER);
-        add(buttonPanel, BorderLayout.SOUTH);
 
         content.setLayout(new GridBagLayout());
         var constraints = new GridBagConstraints();
@@ -91,13 +89,17 @@ public class AccountView extends JPanel {
         addInputRow(constraints, content, typeSpecialProperty, 7, typeSpecialLabel);
         addInputRow(constraints, content, balance, 8, new JLabel("Kontostand", SwingConstants.RIGHT));
 
-        var buttonRightPanel = new JPanel();
+        var buttonPanel = Box.createHorizontalBox();
-        buttonRightPanel.add(transfer);
+        buttonPanel.add(Box.createHorizontalStrut(4));
-        buttonRightPanel.add(deposit);
+        buttonPanel.add(logout);
-        buttonRightPanel.add(takeoff);
+        buttonPanel.add(Box.createHorizontalStrut(4));
-
+        buttonPanel.add(Box.createGlue());
-        buttonPanel.add(logout, BorderLayout.LINE_START);
+        buttonPanel.add(transfer);
-        buttonPanel.add(buttonRightPanel, BorderLayout.LINE_END);
+        buttonPanel.add(Box.createHorizontalStrut(4));
+        buttonPanel.add(deposit);
+        buttonPanel.add(Box.createHorizontalStrut(4));
+        buttonPanel.add(takeoff);
+        add(buttonPanel, BorderLayout.SOUTH);
     }
 
     private void createComponents() {
@@ -124,7 +126,6 @@ public class AccountView extends JPanel {
         this.accountSelection = new JComboBox<>();
 
         this.content = new JPanel();
-        this.buttonPanel = new JPanel(new BorderLayout());
 
         this.logout = new JButton("Abmelden");
         this.transfer = new JButton("Überweisen");

src/me/teridax/jcash/gui/takeoff/TakeoffView.java

@@ -1,6 +1,7 @@
 package me.teridax.jcash.gui.takeoff;
 
 import me.teridax.jcash.banking.Account;
+import me.teridax.jcash.decode.StringUtils;
 
 import javax.swing.*;
 import javax.swing.text.NumberFormatter;
@@ -34,19 +35,6 @@ public class TakeoffView {
         dialog.setVisible(true);
     }
 
-    private NumberFormatter getNumberFormat(double balance) {
-        var format = NumberFormat.getNumberInstance(Locale.GERMANY);
-        format.setParseIntegerOnly(false);
-        format.setMaximumFractionDigits(2);
-
-        var formatter = new NumberFormatter(format);
-        formatter.setValueClass(Double.class);
-        formatter.setAllowsInvalid(true);
-        formatter.setMaximum(balance);
-
-        return formatter;
-    }
-
     private void layoutComponents() {
         dialog.getContentPane().setLayout(new GridBagLayout());
 
@@ -98,7 +86,7 @@ public class TakeoffView {
 
         this.cancel = new JButton("Abbrechen");
         this.deposit = new JButton("Auszahlen");
-        this.value = new JFormattedTextField(getNumberFormat(account.getBalance()));
+        this.value = new JFormattedTextField(StringUtils.LOCAL_NUMBER_FORMAT);
 
         this.dialog.setContentPane(new JPanel(new GridBagLayout()));
     }

src/me/teridax/jcash/gui/transfer/TransferDialog.java

@@ -6,7 +6,7 @@ public class TransferDialog {
 
     public TransferDialog(Account account, Runnable onDeposit) {
         var view = new TransferView(account);
-        view.getDeposit().addActionListener(e -> {
+        view.getTransfer().addActionListener(e -> {
             account.takeoff(view.getAmount());
             onDeposit.run();
             view.dispose();

src/me/teridax/jcash/gui/transfer/TransferView.java

@@ -1,13 +1,12 @@
 package me.teridax.jcash.gui.transfer;
 
 import me.teridax.jcash.banking.Account;
+import me.teridax.jcash.decode.StringUtils;
 
 import javax.swing.*;
-import javax.swing.text.NumberFormatter;
 import java.awt.*;
 import java.text.NumberFormat;
 import java.text.ParseException;
-import java.util.Locale;
 
 import static javax.swing.JOptionPane.ERROR_MESSAGE;
 import static javax.swing.JOptionPane.showMessageDialog;
@@ -16,7 +15,7 @@ public class TransferView {
 
     private JDialog dialog;
     private JButton cancel;
-    private JButton deposit;
+    private JButton transfer;
     private JFormattedTextField iban;
     private JFormattedTextField blz;
     private JFormattedTextField value;
@@ -28,45 +27,33 @@ public class TransferView {
 
     public void showDialog() {
         dialog.setModalityType(Dialog.ModalityType.APPLICATION_MODAL);
-        dialog.setTitle("Deposit money");
+        dialog.setTitle("Transfer money");
         dialog.pack();
+        dialog.setSize(dialog.getWidth() * 2, dialog.getHeight());
         dialog.setResizable(false);
         dialog.setLocationRelativeTo(null);
         dialog.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
         dialog.setVisible(true);
     }
 
-    private NumberFormatter getNumberFormat(double balance) {
-        var format = NumberFormat.getNumberInstance(Locale.GERMANY);
-        format.setParseIntegerOnly(false);
-        format.setMaximumFractionDigits(2);
-
-        var formatter = new NumberFormatter(format);
-        formatter.setValueClass(Double.class);
-        formatter.setAllowsInvalid(true);
-        formatter.setMaximum(balance);
-
-        return formatter;
-    }
-
     private void layoutComponents() {
-        dialog.getContentPane().setLayout(new GridBagLayout());
-
         var c = new GridBagConstraints();
+
         c.gridx = 0;
         c.gridy = 0;
         c.weightx = 1;
         c.weighty = 1;
-        c.fill = GridBagConstraints.BOTH;
+        c.gridwidth = 3;
+        c.fill = GridBagConstraints.HORIZONTAL;
         c.anchor = GridBagConstraints.CENTER;
-        c.insets = new Insets(10, 10, 10, 10);
+        c.insets = new Insets(4, 4, 4, 4);
-        dialog.getContentPane().add(new JLabel("Takeoff money"), c);
+        dialog.getContentPane().add(new JLabel("Transfer money"), c);
 
         c.gridx = 0;
         c.gridy = 1;
+        c.gridwidth = 1;
         c.fill = GridBagConstraints.NONE;
         c.anchor = GridBagConstraints.LAST_LINE_END;
-        c.insets = new Insets(10, 10, 10, 10);
         c.weightx = 0;
         dialog.getContentPane().add(new JLabel("BLZ", SwingConstants.RIGHT), c);
 
@@ -74,15 +61,13 @@ public class TransferView {
         c.gridy = 1;
         c.fill = GridBagConstraints.HORIZONTAL;
         c.anchor = GridBagConstraints.LAST_LINE_END;
-        c.insets = new Insets(10, 10, 10, 10);
+        c.weightx = 0.5;
-        c.weightx = 1;
         dialog.getContentPane().add(blz, c);
 
         c.gridx = 2;
         c.gridy = 1;
         c.fill = GridBagConstraints.NONE;
         c.anchor = GridBagConstraints.LAST_LINE_END;
-        c.insets = new Insets(10, 10, 10, 10);
         c.weightx = 0;
         dialog.getContentPane().add(new JLabel("IBAN", SwingConstants.RIGHT), c);
 
@@ -90,7 +75,6 @@ public class TransferView {
         c.gridy = 1;
         c.fill = GridBagConstraints.HORIZONTAL;
         c.anchor = GridBagConstraints.LAST_LINE_END;
-        c.insets = new Insets(10, 10, 10, 10);
         c.weightx = 1;
         dialog.getContentPane().add(iban, c);
 
@@ -98,7 +82,6 @@ public class TransferView {
         c.gridy = 2;
         c.fill = GridBagConstraints.NONE;
         c.anchor = GridBagConstraints.LAST_LINE_END;
-        c.insets = new Insets(10, 10, 10, 10);
         c.weightx = 0;
         dialog.getContentPane().add(new JLabel("Betrag", SwingConstants.RIGHT), c);
 
@@ -106,35 +89,28 @@ public class TransferView {
         c.gridy = 2;
         c.fill = GridBagConstraints.HORIZONTAL;
         c.anchor = GridBagConstraints.LAST_LINE_END;
-        c.insets = new Insets(10, 10, 10, 10);
+        c.weightx = 0.5;
-        c.weightx = 1;
         dialog.getContentPane().add(value, c);
 
-        c.gridx = 2;
+        var buttonPanel = new JPanel(new FlowLayout(FlowLayout.TRAILING));
+        buttonPanel.add(cancel);
+        buttonPanel.add(transfer);
+
+        c.gridx = 0;
         c.gridy = 3;
+        c.gridwidth = 4;
         c.fill = GridBagConstraints.HORIZONTAL;
         c.anchor = GridBagConstraints.LAST_LINE_END;
         c.insets = new Insets(10, 10, 10, 10);
-        c.weightx = 1;
+        dialog.getContentPane().add(buttonPanel, c);
-        dialog.getContentPane().add(cancel, c);
-
-        c.gridx = 3;
-        c.gridy = 3;
-        c.fill = GridBagConstraints.HORIZONTAL;
-        c.anchor = GridBagConstraints.LAST_LINE_END;
-        c.insets = new Insets(10, 10, 10, 10);
-        c.weightx = 1;
-        dialog.getContentPane().add(deposit, c);
-
-        dialog.getContentPane().add(value, c);
     }
 
     private void createComponents(Account account) {
         this.dialog = new JDialog();
 
-        this.cancel = new JButton("Abbrechen");
+        this.cancel = new JButton("Cancel");
-        this.deposit = new JButton("Auszahlen");
+        this.transfer = new JButton("Transfer");
-        this.value = new JFormattedTextField(getNumberFormat(account.getBalance()));
+        this.value = new JFormattedTextField(StringUtils.LOCAL_NUMBER_FORMAT);
         this.iban = new JFormattedTextField();
         this.blz = new JFormattedTextField();
 
@@ -158,8 +134,8 @@ public class TransferView {
         return cancel;
     }
 
-    public JButton getDeposit() {
+    public JButton getTransfer() {
-        return deposit;
+        return transfer;
     }
 
     public void dispose() {