Java JTextField

Java JTextField

JTextField is a swing component that allows users to edit a single line text.Note the difference with JTextArea allows multiple line text.

How to Declare JTextField class

[public class JTextField extends JTextComponent implements SwingConstants]

Some of the used JTextField constructors

• JTextField()-creates a new JTextField.
• JTextField(String s)-creates a JTexField with a string inside
• JTextField(String s, int cols)-creates  JTextField with a text initialized with a specified number of columns.
• JTextField(int cols)-creates a JTextField with specified number of columns.

JTextField commonly used methods

• void addActionListener(ActionListener listener)-adds action listener to JTextField that makes it possible to receive events from the field.
• Action getAction()-returns the currently action that is set.
• void setFont(Font f)-sets JTextfield font.
• void removeActionListener(ActionListener l)-used to remove action listener so that it does not receive more events.

JTextField example

[

import javax.swing.JFrame;
import javax.swing.JTextField;
public class JavaJTextField {

    public static void main(String args[])
    {
        JFrame frame=new JFrame("JTextField Example");



        JTextField field=new JTextField("Eric Loves programming in Java");
        field.setBounds(50,10, 200,30);
        frame.add(field);
        JTextField field2=new JTextField("This is my blog");
        field2.setBounds(50,150, 200,30);

        frame.add(field2);
        frame.setSize(400,400);
        frame.setLocationRelativeTo(null);
        frame.setLayout(null);
        frame.setVisible(true);



    }

}

]

JTextField with actionListener.

[

import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class JavaJTextField {
    public static JTextField field,field2,field3;
    public static JButton add,subtract;

    public static void main(String args[])
    {
        JFrame frame=new JFrame("JTextField Example");



        field=new JTextField();
        field.setBounds(50,50, 150,20);
        frame.add(field);
        field2=new JTextField();
        field2.setBounds(50,100, 150,20);
        frame.add(field2);
        field3=new JTextField();
        field3.setBounds(50,150, 150,20);
        field3.setEditable(false);
        frame.add(field3);

        add=new JButton("+");
        add.setBounds(50,200,50,50);
        frame.add(add);
        add.addActionListener(new ButtonListener());

        subtract=new JButton("-");
        subtract.setBounds(120,200,50,50);
        frame.add(subtract);
        subtract.addActionListener(new ButtonListener());

        frame.setSize(400,400);
        frame.setLocationRelativeTo(null);
        frame.setLayout(null);
        frame.setVisible(true);



    }

    public static class ButtonListener implements ActionListener
    {
        public void actionPerformed(ActionEvent event)
        {
            String s1=field.getText();
            String s2=field2.getText();
            int a=Integer.parseInt(s1);
            int b=Integer.parseInt(s2);
            int c=0;
            if(event.getSource()==add){
                c=a+b;
            }else if(event.getSource()==subtract){
                c=a-b;
            }
            String result=String.valueOf(c);
            field3.setText(result);


        }

    }
}

]

Output:

See also: Java JButton 

               JTextField getText

Read more about JTextField here