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Java - Swing Applet Example in java

                         

Introduction

In this section we will show you about using swing in an applet. In this example, you will see that how resources of swing are used in the applet. All objects except lbl, have been used from Applet class since lbl which inherits from the JLabel class of the javax.swing.*; package, this is swing label which shows the message in first time This is the Swing Applet Example. when the applet is loaded but again when you click on the Add button and if first text box is blank then the label lbl shows the message Invalid entry! in red color otherwise shows the message Output of the second Text Box : number_in_second_text_box.

Here is the code of the program : 

import javax.swing.*;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;

public class SApplet extends Applet implements ActionListener {
  TextField input,output;
  Label label1,label2;
  Button b1;
  JLabel lbl;
  int num, sum = 0;
  public void init(){
    label1 = new Label("please enter number : ");
    add(label1);
    label1.setBackground(Color.yellow);
    label1.setForeground(Color.magenta);
    input = new TextField(5);
    add(input);
    label2 = new Label("Sum : ");
    add(label2);
    label2.setBackground(Color.yellow);
    label2.setForeground(Color.magenta);
    output = new TextField(20);
    add(output);
//    input.addActionListener( this );
    b1 = new Button("Add");
    add(b1);
    b1.addActionListener(this);
    lbl = new JLabel("This is the Swing Applet Example.          ");
    add(lbl);
    setBackground(Color.yellow);

//    output.addActionListener( this );
  }
  public void actionPerformed(ActionEvent ae){
    try{
//      num = Integer.parseInt(ae.getActionCommand());
      num = Integer.parseInt(input.getText());
      sum = sum+num;
      input.setText("");
      output.setText(Integer.toString(sum));
      lbl.setForeground(Color.blue);
      lbl.setText("Output of the second Text Box : " + output.getText());
    }
    catch(NumberFormatException e){
      lbl.setForeground(Color.red);
      lbl.setText("Invalid Entry!");
    }
  }
}

Here is the HTML code :

<HTML>
<BODY>
<applet code =
"SApplet" width = "260"height = "200"></applet>
</BODY>
</HTML>

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