Applets
Development
- APPLET NAME - applet1
- PURPOSE - Write some text to a standard output
The table below shows the listing for an applet and the explanation of each line of code.
LISTING |
EXPLANATION |
import java.applet.Applet; |
Similar to #include statement in c or c++.
This statement pulls in the classes that are contained in the basic release named java.applet.Applet.
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import java.awt.Graphics; |
This pulls in the classes that are contained in the basic release named java.awt.Graphics (awt=applet window toolkit). |
public class applet1 extends Applet { |
This is a Class definition
The keyword extends indicate that this is a subclass of the Applet class; or,
Applet is a superclass of HelloWorldApplet. |
public void paint(Graphics g) { |
The paint method is passed a Graphics object which we 've to call g.
also to explain paint
then Graphics g
that is all folks |
g.drawString("Abdul H. Aziz!", 50, 25); |
Within the paint method we call g's draw String method to draw the string "Abdul H. Aziz!" at the coordinated (50,25).
50 pixels across
25 pixels down |
} |
this is a synatax thing |
} |
this is a synatax thing |
Compilation
An applet is a Java program that has an extension .java at the end (such as HelloWorldApplet.java). To compile a Java applet type:
javac HelloWorldApplet.java |
UNIX |
javac HelloWorldApplet.java |
Window 95/NT |
Drag the HelloWorldApplet.java file icon
onto Java Compiler icon |
Macintosh |
This will produce a binary file also called byte-code named HelloWorldApplet.class
Running
One of the following commands allow you to view an applet locally.
appletviewer HelloWorldApplet.html |
UNIX |
appletviewer HelloWorldApplet.html |
Windows 95/NT |
Start up the Applet Viewer |
Macintosh |
From the File menu, choose Open HelloWorldApplet.html
This will produce a window with the text "HelloWorld"
Embedding in html pages
<applet code="name.class" width=integer height=interger>
Please send questions or suggestions about this web page to beatnic@aset.psu.edu
ASET | ITS | Penn State
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