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How to create an event listener in Applet in Java
Problem Description
How to create an event listener in Applet?
Solution
Following example demonstrates how to create a basic Applet having buttons to add & subtract two nos. Methods used here are addActionListener() to listen to an event(click on a button) & Button() construxtor to create a button.
import java.applet.*; import java.awt.event.*; import java.awt.*; public class EventListeners extends Applet implements ActionListener { TextArea txtArea; String Add, Subtract; int i = 10, j = 20, sum = 0, Sub = 0; public void init() { txtArea = new TextArea(10,20); txtArea.setEditable(false); add(txtArea,"center"); Button b = new Button("Add"); Button c = new Button("Subtract"); b.addActionListener(this); c.addActionListener(this); add(b); add(c); } public void actionPerformed(ActionEvent e) { sum = i + j; txtArea.setText(""); txtArea.append("i = "+ i + "\t" + "j = " + j + "\n"); Button source = (Button)e.getSource(); if(source.getLabel() == "Add") { txtArea.append("Sum : " + sum + "\n"); } if(i > j) { Sub = i - j; } else { Sub = j - i; } if(source.getLabel() == "Subtract") { txtArea.append("Sub : " + Sub + "\n"); } } }
Result
The above code sample will produce the following result in a java enabled web browser.
View in Browser.
java_applets.htm
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