The applet below shows the mouse position in black if moved, in blue if dragged and repaints in red if clicked. Applets can also interact with the keyboard, but this is less common. The following applet does all activities that majority of educational applets need: it responds to mouse clicks and drags and orders to repaint itself after the 100 ms in order to reflect the mouse manipulations. Of course, you can also have your own website, but there your applet may be more difficult to find.Įxample with mouse listener Many applets are also deployed at project pages. Unlike pictures, applets are currently not accepted in Wikipedia, but there are some alternative initiatives like. When you complete your first functional applet, you likely will want to share it somewhere. The following example is made simple enough to illustrate the essential use of Java applets through its java.applet package.Īpplet inclusion is described in detail in Sun's official page about the APPLET tag. However, it is complex and expensive to do this in a proper way, and if done wrongly (like self-signing) the signature can make the applet look untrustworthy. Traditional programs can do so using so-called native methods.Īpplet security restrictions can be lifted up by creating a so-called signed applet that verifies your identity through an independent authority server.

Applets can't use other language libraries like C and C++.

Applets can't communicate with other services of the network, apart the originating server.

This feature provides security to the applets from the local computer and to the local computer from applets.

Applets can not read or write to a local computer.

The rest of activity usually happen in various event listeners, registered by init() on the applet components. Method init() is called on startup and must setup the applet.

Applets do not use the main() method of Java (the traditional Java programs are required to do so).

There are many restrictions with applets. They basically are developed for small tasks. They are not full featured application programs. Also, for many simple applets, it is common to just register the mouse listener on the same applet, call repaint() from mouse events when required and provide the paint(Graphics g) method to draw the applet how it must look at the given moment of time. Both inherit from Container, so if you know how to build JFrame or Frame (used in standalone applications), you largely know how to build the applet. Applet is derived either from Applet or the newer JApplet class. An applet can perform functions like displaying graphics, animation, accept user input, etc. They can be viewed using an applet viewer or any browser. Applets are Java programs that are used in Internet computing.

Make applet dimensions in applet viewer