The init(), start(), stop(), and destroy() methods areīrowser to direct the applet’s behavior. Should be easily adaptable to either a standalone or appletĬontains four methods that can be overridden to guide it through its
Normally, you’ll use your applet class itself onlyĪs a thin wrapper to manage the lifecycle and appearance of yourĪpplication-create the GUI, start, and stop. Manager, you can structure it to function as both an applet and a If yourĪpplication can live within the limits imposed by a browser’s security There is no difference between an applet and an application. Have additional structure that helps them interact with the browserĪside from the top-level structure and the security restrictions, JApplet by overriding its paint() method andĭisplay area by providing the appropriate event listeners. Like any other Panel, a JApplet can contain user interface componentsĪnd use all the basic drawing and event-handling capabilities of the As Figure 23-1 shows, an applet is a kind of In all other respects, however, applets are just ordinary In a page and used in a viewing environment that provides it with The browser provides everything the applet needs through an The restrictions are enforced by an applet security The webīrowsers that run applets impose restrictions on what the applet isĪllowed to do. Pragmatically, an applet is an intruder into someone else’sĮnvironment and therefore has to be treated with suspicion. The name of the applet class and a size in pixels for the applet: Instead of having your application create a JFrame to hold your GUI, you stuff yourĪpplets are placed on web pages with the HTML tag, Thus, an applet can’t run by itself it runs in the context ofĪ web browser or a special applet-viewer program (which we’ll talk about To a standalone graphical Java application, which starts up from aĪpplet itself is a component that expects to be dropped into someoneĮlse’s GUI. Structurally, an applet is a wrapper for your Java code. Historically, applets have tended to be small “widgets.”ĭefines the core functionality of an applet. Tend to be relatively simple, there’s no inherent restriction on theirĬomplexity other than the issues of downloading and caching their content. Applets also have a lifecycle that lets themĪct more like an application than a static component. That has some extra structure to allow it to be used in the “alien”Įnvironment of a web browser.
Compile and Run the programType the following command to compile the WaterApp.java file: javac WaterApp.javaAnd type the following command to run the program: java WaterAppA small window appears: Enter the number 70 into the text field and click the button, a message dialog appears: And now, let try test the program yourself to see how it works.Congratulations! You have successfully created your first Swing program.A JApplet is a Swing JPanel with a mission. Public class WaterApp extends JFrame implements ActionListener That’s all for the coding stuffs. * A Java Swing program that shows how much water you should drink a day. And see our detailed explanation after the code: import javax.swing.*
#Open applet viewer using actionperformed how to#
How to show a message box using the JOptionPane class.You can use any text editor of your choice ( TextPad, NotePad, WordPad, Sublime, etc), and using the commands javac and java to compile and run the program.Here’s the full source code of the program - WaterApp. How to handle the click event of a button. How to arrange components on the frame using FlowLayout - a simple layout manager. How to use button using the JButton class. How to use text field using the JTextField class. How to use label using the JLabel class. How to create a window using the JFrame class. When the user clicks the Tell Me button, a message dialog appears telling the exact amount of water.Technically, you will learn the following things: Throughout this tutorial, we will guide you how to build a Java desktop application that looks something like this: You see, this is a small Swing program that allows the user to enter his or her weight (kg) and calculate the amount of water he or she should drink every day, according to the given formula. This Java tutorial is designed for those who are new in Swing - the GUI APIs for developing desktop applications in Java.