Simple Calculator in Java Applet

As we have already learned about applet and applet life cycle.

Next we will create a simple calculator program in java using applet.

Java applet program for calculator is as below

Below is the output of the calculator program in java

Java Applet Simple Calculator Example

Applet Life Cycle in Java

Applet is a special Java program that are primarily used in a internet programming. 

Applet program runs on a web browser at client side. Applet program are used to make the web site more dynamic.

When the applet program is loaded is passes through several stages:

Java Applet Life Cycle
Java Applet Life Cycle

Born:  Also known as initialization state.  It is the first state of applet lifecycle.

Applet enters in a born/initialization state when it is first loaded.  

Applet moves in a born state when init() method of Applet class executes.

Applet initialization occurs once in a  applet lifecycle. Inside the init() method we initialize all the variables.

Syntax of init() 

Running :  Applet enters in a running state from born state when a start() method of Applet class executes.  

Running sates call automatically when the initialization phase completes. 

Applet also comes in a running state from idle state when idle applet again get processor.

Running sates call automatically when the initialization phase completes. 

Applet also comes in a running state from idle state when idle applet again get processor.

Syntax of start()              

Idle : A running appletenters in a idle sate from running state when execution of start complete.

In a another words when we leave the page of running applet then automatically it enters in a idle sate from running state.

Applet moves in idle state when  stop() method executes and it moves idle to running state when again start() calls.

Syntax of stop()               

Dead :  An applet is moved to dead state when we quit the web browser.  When applet moves in a dead state it removed from memory. 

The Applet will be terminate when destroy () method calls. In a applet lifecycle, applet terminates/destroys ones.

Syntax of destroy()        

Display State: The Display state executes immediately after when applet enters in a running state.

In this state we display the information on the output screen using paint() method.

Basics of Applet in Java

The Java Applet is a special Java program that are primarily used in a internet programming.

Applet program runs on a web browser at client side.

Applet program are used to make the web site more dynamic.

Applet program embedded in a HTML page and hosted on a web server.

Applet Skeleton/ Structure

Applet skeleton is a structure/ syntax of applet program. 

Any applet program created by us must be sub class of Applet class. Applet program may contain five methods: