Java Swing | JTextArea

Difficulty Level : Hard
Last Updated : 20 Nov, 2019

JTextArea is a part of java Swing package . It represents a multi line area that displays text. It is used to edit the text .
JTextArea inherits JComponent class. The text in JTextArea can be set to different available fonts and can be appended to new text . A text area can be customized to the need of user .

Constructors of JTextArea are:

JTextArea() : constructs a new blank text area .
JTextArea(String s) : constructs a new text area with a given initial text.
JTextArea(int row, int column) : constructs a new text area with a given number of rows and columns.
JTextArea(String s, int row, int column) : constructs a new text area with a given number of rows and columns and a given initial text.

Commonly used methods :

append(String s) : appends the given string to the text of the text area.
getLineCount() : get number of lines in the text of text area.
setFont(Font f) : sets the font of text area to the given font.
setColumns(int c) : sets the number of columns of the text area to given integer.
setRows(int r) : sets the number of rows of the text area to given integer.
getColumns() : get the number of columns of text area.
getRows() : get the number of rows of text area.

1. Program to create a simple JTextArea

// Java Program to create a simple JTextArea
import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
class text extends JFrame implements ActionListener {
  
    // JFrame
    static JFrame f;
  
    // JButton
    static JButton b;
  
    // label to display text
    static JLabel l;
  
    // text area
    static JTextArea jt;
  
    // default constructor
    text()
    {
    }
  
    // main class
    public static void main(String[] args)
    {
        // create a new frame to store text field and button
        f = new JFrame("textfield");
  
        // create a label to display text
        l = new JLabel("nothing entered");
  
        // create a new button
        b = new JButton("submit");
  
        // create a object of the text class
        text te = new text();
  
        // addActionListener to button
        b.addActionListener(te);
  
        // create a text area, specifying the rows and columns
        jt = new JTextArea(10, 10);
  
        JPanel p = new JPanel();
  
        // add the text area and button to panel
        p.add(jt);
        p.add(b);
        p.add(l);
  
        f.add(p);
        // set the size of frame
        f.setSize(300, 300);
  
        f.show();
    }
  
    // if the button is pressed
    public void actionPerformed(ActionEvent e)
    {
        String s = e.getActionCommand();
        if (s.equals("submit")) {
            // set the text of the label to the text of the field
            l.setText(jt.getText());
        }
    }
}

Output:

2. Program to create a JTextArea and set a initial text and add buttons to change the font of text area.

// Java Program Program to create a JTextArea and
// set a initial text and add buttons to change
// the font of text area.
import java.awt.event.*;
import java.awt.*;
import javax.swing.*;
class text11 extends JFrame implements ActionListener {
  
    // JFrame
    static JFrame f;
  
    // JButton
    static JButton b, b1, b2, b3;
  
    // label to display text
    static JLabel l, l1;
  
    // text area
    static JTextArea jt;
  
    // default constructor
    text11()
    {
    }
  
    // main class
    public static void main(String[] args)
    {
        // create a new frame to store text field and button
        f = new JFrame("textfield");
  
        // create a label to display text
        l = new JLabel("nothing entered");
        l1 = new JLabel("0 lines");
  
        // create a new buttons
        b = new JButton("submit");
        b1 = new JButton("plain");
        b2 = new JButton("italic");
        b3 = new JButton("bold");
  
        // create a object of the text class
        text11 te = new text11();
  
        // addActionListener to button
        b.addActionListener(te);
        b1.addActionListener(te);
        b2.addActionListener(te);
        b3.addActionListener(te);
  
        // create a text area, specifying the rows and columns
        jt = new JTextArea("please write something ", 10, 10);
  
        JPanel p = new JPanel();
  
        // add the text area and button to panel
        p.add(jt);
        p.add(b);
        p.add(b1);
        p.add(b2);
        p.add(b3);
        p.add(l);
        p.add(l1);
  
        f.add(p);
        // set the size of frame
        f.setSize(300, 300);
  
        f.show();
    }
  
    // if the button is pressed
    public void actionPerformed(ActionEvent e)
    {
        String s = e.getActionCommand();
        if (s.equals("submit")) {
            // set the text of the label to the text of the field
            l.setText(jt.getText() + ", ");
            l1.setText(jt.getLineCount() + " lines");
        }
        else if (s.equals("bold")) {
  
            // set bold font
            Font f = new Font("Serif", Font.BOLD, 15);
            jt.setFont(f);
        }
        else if (s.equals("italic")) {
            // set italic font
            Font f = new Font("Serif", Font.ITALIC, 15);
            jt.setFont(f);
        }
        else if (s.equals("plain")) {
            // set plain font
            Font f = new Font("Serif", Font.PLAIN, 15);
            jt.setFont(f);
        }
    }
}

Output :

Note : The following program might mot run in an online compiler please use an offline IDE

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