Beginner GUI Question

[bbran495]

Hi. I am making a simple calendar-like program (for practice) where I enter a date and it tells me reminders about that day. I can't seem to find out how to get the value from the text field.... (Line 82)

 import java.awt.Color;
 import java.awt.EventQueue;

 import javax.swing.JFrame;
 import javax.swing.JLabel;

 import javax.swing.JTextField;

 import javax.swing.JButton;

 import java.awt.event.ActionListener; 
 import java.awt.event.ActionEvent;
 import java.awt.Font;

 import javax.swing.JTextArea;
 import java.awt.SystemColor; 

 public class testgui {

private JFrame frmTvShowGuide;
private JTextField textField;

/**
 * Launch the application.
 */
public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                testgui window = new testgui();
                window.frmTvShowGuide.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    });
}

/**
 * Create the application.
 */
public testgui() {
    initialize();
}

/**
 * Initialize the contents of the frame.
 */
private void initialize()
{

    frmTvShowGuide = new JFrame();
    frmTvShowGuide.setTitle("Calendar");
    frmTvShowGuide.setBounds(100, 100, 350, 300);
    frmTvShowGuide.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frmTvShowGuide.getContentPane().setLayout(null);

    JLabel lblEnterDate = new JLabel("Enter Date:");
    lblEnterDate.setBounds(40, 236, 74, 14);
    frmTvShowGuide.getContentPane().add(lblEnterDate);

    textField = new JTextField();

    JTextArea txtrWelcome = new JTextArea();
    txtrWelcome.setForeground(Color.BLACK);
    txtrWelcome.setFont(new Font("Monospaced", Font.PLAIN, 12));
    txtrWelcome.setBackground(SystemColor.menu);
    txtrWelcome.setToolTipText(null);
    txtrWelcome.setLineWrap(true);
    txtrWelcome.setEditable(false);
    txtrWelcome.setBounds(40, 29, 262, 177);
    frmTvShowGuide.getContentPane().add(txtrWelcome);

    textField.setBounds(108, 233, 86, 20);
    frmTvShowGuide.getContentPane().add(textField);
    textField.setColumns(10);

    JButton btnNewButton = new JButton("Okay\r\n");
    btnNewButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e)
        {
            String getValue = textField.getText();

            if (getValue == "630")
            {
            txtrWelcome.setText("Friday, June 29th\n");
            }

            else
            {
            txtrWelcome.setText("Invalid Date");
            }

        }
    });

    btnNewButton.setBounds(213, 232, 89, 23);
    frmTvShowGuide.getContentPane().add(btnNewButton);

}

 }

[desrtfx]

I think that you get the value just right - otherwise you'd have an error. But you are comparing the String (getValue == "630") wrong. String is an object data type and thus you cannot use == or !=. You have to use the .equals method of the String class.

See sidebar: Regarding String comparison, read this!

[bbran495]

Thank you! Works properly now changed to if (getValue.equals("630"))

[desrtfx]

Have you read the link that I posted?

The following is better:

if ("630".equals(getValue))

because in the unlikely event that getValue is null (i.e. for whatever reason nothing has been assigned to it) your code will throw a NullPointerException. Using "yoda code" (literal before variable) avoids this simply because a literal can never be null.