Mapping KeyStrokes to an array of JButtons

Question

Hi. I'm working on a calculator program. It has a scrollPanel with an uneditable JTextPane at the top and a 10x4 gridJPanel of buttons at the bottom. All the buttons are generated at once, as part of a 40 button JButton array.
Here's the code where I generate the buttons...
String[] buttonNames =
                    "ans", "rand", "back", "clear",
                    "abs", "e", "pi", "inv",
                    "sin", "cos", "tan","rad",
                    "csc", "sec", "cot", "mod",
                    "E", "log", "ln", "^",
                    "sqrt", "(", ")", "/",
                    "1", "2", "3", "*",
                    "4", "5", "6", "-",
                    "7", "8", "9", "+",
                    "0", ".", "+/-", "enter"
for (int i=0; i<40; i++)
                    buttons[i] = new JButton(buttonNames);
                    buttons[i].setPreferredSize( new Dimension(30, 35));
                    buttons[i].addActionListener(this);
                    add(buttons[i]);
The buttons all have the same action assigned to them, as you can see. In the code for the action, what to do is determined by if statements. Here's a block of code from there...
public void actionPerformed(ActionEvent e)
               JButton whichClicked = (JButton)e.getSource();
               else if (whichClicked.getText() == "/")
                    try
                         doc.insertString(doc.getLength(), "/", null);
                    catch(Exception ble) {}
                    expression = expression + "/";
                    lastEntered = "operator";
               else if (whichClicked.getText() == "1")
                    try
                         doc.insertString(doc.getLength(), "1", null);
                    catch(Exception ble) {}
                    expression = expression + "1";
                    lastEntered = "number";
               else if (whichClicked.getText() == "2")
                    try
                         doc.insertString(doc.getLength(), "2", null);
                    catch(Exception ble) {}
                    expression = expression + "2";
                    lastEntered = "number";
               else if (whichClicked.getText() == "3")
                    try
                         doc.insertString(doc.getLength(), "3", null);
                    catch(Exception ble) {}
                    expression = expression + "3";
                    lastEntered = "number";
               else if (whichClicked.getText() == "*")
                    try
                         doc.insertString(doc.getLength(), "*", null);
                    catch(Exception ble) {}
                    expression = expression + "*";
                    lastEntered = "operator";
//AND SO ON AND SO FORTH...You get the idea. Anyway, what I want to do is somehow make it so that I can assign KeyStrokes to certain buttons (for instance, pressing 3 on the NumPad of the keyboard will go to the action for the "3" JButton and add 3 to the text pane), to expedite the process of entering numbers into the JTextPane. However, the JTextPane is uneditable, so that can't be done directly.
Will simple InputMaps and ActionMaps work? Does anybody have any ideas?
I appreciate the help - thanks in advance
Nick

Answer 1

Never mind. I figured it out myself. For anyone who's interested / for everyone's future reference, I used arrays and for loops to map specific keys to specific buttons.
Here's what I finally ended up with.
     class ButtonsPanel extends JPanel
          ButtonsPanel()
               setLayout(new GridLayout(10,4));
               setBorder(BorderFactory.createEmptyBorder(3,3,3,3));
               String[] buttonNames =
                    "ans", "rand", "back", "clear",
                    "abs", "e", "pi", ">deg",
                    "sin", "cos", "tan",">rad",
                    "csc", "sec", "cot", "mod",
                    "E", "log", "ln", "^",
                    "sqrt", "(", ")", "/",
                    "1", "2", "3", "*",
                    "4", "5", "6", "-",
                    "7", "8", "9", "+",
                    "0", ".", "+/-", "enter"
               Action buttonClicked = new buttonClickedAction();
               for (int i=0; i<40; i++)
                    buttons[i] = new JButton();
                    buttons.setPreferredSize( new Dimension(30, 30));
                    buttons[i].setAction(buttonClicked);
                    buttons[i].setText(buttonNames[i]);
                    add(buttons[i]);
               int[] buttonsWithKeyBindings = {2,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39};
               String[] keyBindings =
                    "BACK_SPACE", "LEFT_PARENTHESIS", "RIGHT_PARENTHESIS", "DIVIDE", "NUMPAD1",
                    "NUMPAD2", "NUMPAD3", "MULTIPLY", "NUMPAD4", "NUMPAD5", "NUMPAD6", "SUBTRACT",
                    "NUMPAD7", "NUMPAD8", "NUMPAD9", "ADD", "NUMPAD0", "DECIMAL", "SUBTRACT", "ENTER"
               for (int i=0; i<20; i++)
                    buttons[buttonsWithKeyBindings[i]].getInputMap(WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke(keyBindings[i]), "typed");
                    buttons[buttonsWithKeyBindings[i]].getActionMap().put("typed", buttonClicked);
     class buttonClickedAction extends AbstractAction
          public void actionPerformed(ActionEvent e)
               JButton whichClicked = (JButton)e.getSource();
               if (whichClicked.getText() == "ans")
                    try
                         doc.insertString(doc.getLength(), "ans", null);
                    catch(Exception ble) {}
                    expression.append("ans");
                    lastEntered = "operator";
                    lengthOfLast = 3;
               else if (whichClicked.getText() == "rand")
                    long randomNumber = Math.round(Math.floor(Math.random() * 10));
                    try
                         doc.insertString(doc.getLength(), String.valueOf(randomNumber), null);
                    catch(Exception ble) {}
                    expression.append(randomNumber);
                    lastEntered = "number";
                    lengthOfLast = 1;
// etc. etc. etc.
Nick