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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