Question

I am working on an swing application and struck at deciding what could be the best way to save values of large number of JTextFields.
The application reads a property file from some network location. Property file have around 10-12 properties for each particular user say propertyA_1 is property for user 1 and propertA_2 for user 2. There will be around 10-12 users in a properties, So it will make around 80 JTextField to show values. Each user’s properties will be shown on a JTabbedPane.
What I want to do now is that when user changes value of any JTextField for any user shown in each JTabbedPane and clicks on “Save” buttton, the value for the property should be saved.
Tell me what could be the best way to handle large number of JtextField. I think of doing it 2 ways

1. On Click of “Save” button save each value of property by getting value from all JTextFields.
2. Some way to get only those JTextFields for which text is changed and save their values.

I am not sure how to do the thing by Option 2.But I think this is the best way.

Here is my code :

public class IOSAutomationTool1 implements ActionListener {

       JButton saveButton  = new JButton("Click to Save");

    /**
     * @param args the command line arguments
     */

    public  void Test() throws IOException {

         File file = new File("C:\\Documents and Settings\\test\\Desktop\\test.properties");

         if( file != null ){

             Properties property = new Properties();

             property.load(new FileInputStream(file));

              JFrame frame = new JFrame("IOSAutomationToolFourthPage");
              frame.setLayout(new FlowLayout());
              JPanel framePanel = new JPanel();
              JPanel buttonPanel = new JPanel();
              framePanel.setSize(700,700);
               frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
              String numberOfClients = property.getProperty("numberOfClients");
              System.out.println("number of clients: "+numberOfClients);


                saveButton.addActionListener(this);
                buttonPanel.add(saveButton);
              if (!numberOfClients.isEmpty()) {

                   int numberOfClientNumb = Integer.parseInt(numberOfClients);

                      System.out.println("numberOfClientNumb ::" + numberOfClientNumb);

                       JTabbedPane tab = new JTabbedPane();

                      // JTabbedPane tab2 = new JTabbedPane();
                    for( int i=1; i<=numberOfClientNumb; i++){

                       JPanel panel = new JPanel();
                      panel.setSize(400, 400);
                      panel.setLayout(new GridBagLayout());
                      GridBagConstraints gbc = new GridBagConstraints();
                       gbc.insets = new Insets(1, 1, 1, 1);

                        gbc.fill = GridBagConstraints.BOTH;
                        gbc.weightx = 0;
                        gbc.gridx = 0;

                      //Remote IP 
                      JLabel remoteIPLbl = new JLabel("Remote IP : ");
                      panel.add(remoteIPLbl,gbc);
                      JLabel userNameLbl = new JLabel("User Name : ");
                      panel.add(userNameLbl,gbc);
                      JLabel remotePasswordLbl = new JLabel("Remote Password : ");
                      panel.add(remotePasswordLbl,gbc);
                      JLabel remotePathLbl = new JLabel("Remote Path : ");
                      panel.add(remotePathLbl,gbc);
                      JLabel deviceOrSimulatorLbl = new JLabel("Device or Simulator : ");
                      panel.add(deviceOrSimulatorLbl,gbc);

                      gbc.gridx = 1;
                      gbc.weightx = 1;

                      String remoteIPVal = property.getProperty("remoteIP_"+i);
                      JTextField remoteIPField = new JTextField(remoteIPVal);
                      //remoteIPLbl.setBounds(50, 100, 2, 2);
                     remoteIPField.setBounds(200, 100, 2, 2);
                      remoteIPField.setColumns(30);
                      panel.add(remoteIPField,gbc);    

                      //Remote User Name


                      String userNameVal = property.getProperty("remoteUserName_"+i);
                      JTextField userNameField = new JTextField(userNameVal);
                     // userNameLbl.setBounds(50, 200, 2, 2);
                      userNameField.setBounds(200, 200, 2, 2);
                      userNameField.setColumns(20);
                      panel.add(userNameField,gbc);   

                      //Remote Password

                      String remotePasswordVal = property.getProperty("remotePassword_"+i);
                      JTextField remotePasswordField = new JTextField(remotePasswordVal);
                     // remotePasswordLbl.setBounds(50, 300, 2, 2);
                      remotePasswordField.setBounds(200, 300, 2, 2);
                      remotePasswordField.setColumns(20);
                      panel.add(remotePasswordField,gbc); 


                      //Remote Path

                      String remotePathVal = property.getProperty("remotePath_"+i);
                      JTextField remotePathField = new JTextField(remotePathVal);
                     // remotePathLbl.setBounds(50, 400, 2, 2);
                     remotePathField.setBounds(200, 400, 2, 2);
                      remotePathField.setColumns(100);
                      panel.add(remotePathField,gbc); 



                      //deviceOrSimulator

                      String deviceOrSimulatorVal = property.getProperty("deviceOrSimulator_"+i);
                      JTextField deviceOrSimulatorField = new JTextField(deviceOrSimulatorVal);
                      //deviceOrSimulatorLbl.setBounds(50, 500, 2, 2);
                      deviceOrSimulatorField.setBounds(200, 500, 2, 2);
                      deviceOrSimulatorField.setColumns(1);
                      panel.add(deviceOrSimulatorField,gbc); 


                      tab.add("Client "+i,panel);
                      System.out.println(""+i);                     
                   }

                    framePanel.add(tab);

                    frame.add(framePanel);

                   // frame.setLayout(new Lay);
              }
               //frame.add(saveButton);
               frame.add(buttonPanel);
              frame.setSize(800, 800);
              frame.pack();
              frame.setVisible(true);

         }
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        //throw new UnsupportedOperationException("Not supported yet.");

        if(e.getSource() == saveButton){
            System.out.print("button clicked...........");
        }
    }

    public static void main(String[] args) throws IOException{

        IOSAutomationTool1 obj = new IOSAutomationTool1();
        obj.Test();
    }
}

Answer 1

To elaborate a bit over what @nlcE cOw is suggesting, what you could do is something like this:

1) Make your property final:

        final Properties property = new Properties();

2) Before your for-loop, create a DocumentListener:

    DocumentListener listener = new DocumentListener() {

        private void updatePropertyForEvent(final Properties property, DocumentEvent e) {
            Document document = e.getDocument();
            Object value = document.getProperty("key");
            if (value !=null)
                try {
                    property.setProperty((String) value, document.getText(0, document.getLength()));
                } catch (BadLocationException e1) {
                    // Should not happpen
                    e1.printStackTrace();
                }
        }

        @Override
        public void removeUpdate(DocumentEvent e) {
            updatePropertyForEvent(property, e);
        }

        @Override
        public void insertUpdate(DocumentEvent e) {
            updatePropertyForEvent(property, e);                
        }

        @Override
        public void changedUpdate(DocumentEvent e) {
            updatePropertyForEvent(property, e);                
        }
    };

3) For each textfield you create, you put a property on the associated document that will store which property it represents and you add the listener as a DocumentListener:

String remotePasswordVal = property.getProperty("remotePassword_"+i);
JTextField remotePasswordField = new JTextField(remotePasswordVal);
remotePasswordField.getDocument().putProperty("key", "remotePassword_"+i);
remotePasswordField.getDocument().addDocumentListener(listener);

4) When you press “Save”, you simply save property to an outputStream.

This is the quick & dirty solution. A cleaner option would be to use a proper MVC-pattern.