TextField & JTextComponent

TextField

The TextField component is used for implementing or editing a single-line text entry. It performs the event on pressing and releasing a key. The TextField is subclass of the TextComponent.

TextField Class Constructors

Constructors	Description
TextField()	Constructs a new text field.
TextField(int columns)	Constructs a new empty text field with the specified number of columns.
TextField(String str)	Creates a new text field initialized with specified text.
TextField(String str, int columns)	Constructs a new text field with the specified text to be displayed, and it holds the specified number of columns.

JTextComponent

Swing text components display text and optionally allow the user to edit the text. The JComponents are basically used for making style – unstyle.

JTextComponent Hierarchy

JTextComponent hierarchy is shown in below.

jcomponent

1. JTextField

The JTextField is a lightweight component that allows the editing of a single line of text. It is encapsulated by the JTextComponent.

JTextField Constructors

Constructors	Description
JTetxField()	Used to construct a new TextFiled.
JTetxField(Document doc, String str, int cols)	Constructs a new JTextField that uses the given text storage model and given number of columns.
JTetxField(int cols)	Constructs new empty TextField with the given number of columns.
JTetxField(String str)	Constructs a new TextField initialized with the specified string.
JTetxField(String str, int cols)	Constructs a new TextField with the specified string value and columns.

Example: Creating textfield and buttons

// FrameTest.java

import java.awt.*;
import java.awt.event.*;
public class FrameTest extends Frame implements ActionListener
{
    String title;
    Button b1, b2;
    TextField text1, text2;
    public FrameTest(String title)
    {
       super(title);
       setLayout(new FlowLayout());
       text1 = new TextField(20);
       b1 = new Button("Reset");
       text2 = new TextField(20);
       b2 = new Button("Submit");
       add(text1);
       add(b1);
       add(text2);
       add(b2);
       b1.addActionListener(this);
       b2.addActionListener(this);
    }
    public void actionPerformed(ActionEvent e)
    {
       String str = "";
       if(e.getSource() == b1)
       {
          text1.setText(str+" You click reset button..");
       }
       if(e.getSource() == b2)
       {
          text2.setText(str+" You click submit button..");
       }
    }
    public static void main(String args[])
    {
        FrameTest frame = new FrameTest("Frame with TextField & Button:");
        frame.setSize(300,200);
        frame.setBackground(Color.pink);
        frame.setVisible(true);
    }
}

Output:

2. JPasswordField

The JPassword field extends from the JTextField. It is a lightweight component that allows to type password text entry. By default, JPasswordField disable input methods, means input character could not be visible.

Creating JPasswordField

JPasswordField password = new JPasswordField(10);

JPasswordField Constructors

Constructors	Description
JPasswordField()	Creates a new password field.
JPasswordField(Document doc, String str, int size)	Creates a new JPassword field that uses the given text storage model and specifies the password size.
JPasswordField(int size)	Constructs a new JPasswordField with the specified number of characters.
JPasswordField(String str)	Constructs the new JPassword field initialized with specified text.
JPasswordField(String str, int size)	Constructs a new JPasswordField initialized with the specified text and size.

Example: Illustrating JTextField and JPasswordField

// JPasswordDemo.java

import javax.swing.*;
public class JPasswordDemo
{
   public static void main(String args[])
   {
      JFrame frame = new JFrame("JPasswordField & JTextField");
      JPanel panel = new JPanel();
      JLabel l1 = new JLabel("Username");
      JLabel l2 = new JLabel("Password");
      JLabel l3 = new JLabel("Confirm !!!");
      JTextField text = new JTextField(20);
      JPasswordField pass1 = new JPasswordField(20);
      JPasswordField pass2 = new JPasswordField(20);
      panel.add(l1);
      panel.add(text);
      panel.add(l2);
      panel.add(pass1);
      panel.add(l3);
      panel.add(pass2);
      frame.add(panel);
      frame.setSize(350, 150);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.setVisible(true);
   }
}

Output:
jpassword

3. JFormattedTextField

JFormattedTextField extends JTextField adding support for formatting arbitrary value. It provides the specific text entry component into the TextField.

Creating JFormattedTextField

JFormattedTextField ftf = new JFormattedTextField();

JFormattedTextField Constructor

JFormattedTextField()
JFormattedTextField(Format format)
JFormattedTextField(Object value)
JFormattedTextField(AbstractFormatter formatter)
JFormattedTextField(AbstractFormatterFactory factory)
JFormattedTextField(AbstractFormatterFactory factory, Objetc obj)

Example : Illustrate the JFormattedTextField

// JFormattedTextFieldDemo.Java

import javax.swing.*;
public class JFormattedTextFieldDemo
{
       public static void main(String args[])
       {
             JFrame frame = new JFrame("JFormattedTextField ");
             JPanel panel = new JPanel();
             JFormattedTextField jft1 = new JFormattedTextField();
             String date = new String();
             date = "Date";
             jft1 = new JFormattedTextField(new java.util.Date());
             JLabel label1 = new JLabel(date);
             panel.add(label1);
             panel.add(jft1);
             JFormattedTextField jft2 = new FormattedTextField(java.text.NumberFormat.getCurrencyInstance());
             jft2.setValue(new Float(50.50));
             JLabel label2 = new JLabel("Currency");
             panel.add(label2);
             panel.add(jft2);
             frame.add(panel);
             frame.setSize(350, 180);
             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
             frame.setVisible(true);
     }
}

Output:

jformttedtextfield