Using Applet dimension to print center aligned text Example

1. /*
2. Using Applet dimension to print center aligned text Example
3. This Java example shows how to print text in center of an applet window using
4. Dimension class.
5. */
6.  
7. import java.applet.Applet;
8. import java.awt.Dimension;
9. import java.awt.Font;
10. import java.awt.FontMetrics;
11. import java.awt.Graphics;
12.  
13. /*
14. <applet code = "AppletDimensionExample" width = 500 height = 300>
15. </applet>
16. */
17.  
18. public class AppletDimensionExample extends Applet{
19.  
20. public void paint(Graphics g){
21. int x,y;
22. String s = "Hello World";
23.  
24. //get applet size using getSize method
25. Dimension d = getSize();
26. Font f = new Font("Arial",Font.BOLD,24);
27. g.setFont(f);
28.  
29. //determine x and y coordinates
30. FontMetrics fm = g.getFontMetrics();
31. x = d.width/2 - fm.stringWidth(s)/2;
32. y = d.height/2 - fm.getHeight();
33.  
34. //print string at specified location using drawString method
35. g.drawString(s,x,y);
36. }
37. }

Get Applet parameter Example

1. /*
2. Get Applet parameter Example
3. This java example shows how get the parameter passed to an applet using
4. getParameter() method of Java Applet class.
5. */
6.  
7. import java.applet.Applet;
8. import java.awt.Graphics;
9.  
10. /*
11.  * To pass a parameter to an Applet use <param> HTML tag.
12.  * Specify name and value attribute to pass a parameter to an applet like
13.  * given below.
14.  *
15.  * <param name="paramName" value="paramValue"/>
16.  *
17.  * You can pass multiple parameters for an Applet using multiple
18.  * <param> HTML tag.
19.  */
20.  
21. /*
22. <applet code="GetAppletParameterExample" width=200 height=200>
23. <param name="msg" value="This is a parameter example program"/>
24. <param name="xPosition" value="50"/>
25. <param name="yPosition" value="50"/>
26. </applet>
27. */
28.  
29. public class GetAppletParameterExample extends Applet{
30.  
31. public void paint(Graphics g){
32.  
33. int x = 0;
34. int y = 0;
35. String msg = "";
36.  
37. try{
38. x = Integer.parseInt(getParameter("xPosition"));
39. }
40. catch(NumberFormatException ne){
41. msg = msg + "Invalid x Value";
42. }
43.  
44. try{
45. y = Integer.parseInt(getParameter("yPosition"));
46. }
47. catch(NumberFormatException ne){
48. msg = msg + "Invalid y Value";
49. }
50.  
51. msg = getParameter("msg");
52.  
53. g.drawString(msg, x, y);
54. }
55. }

Basic Java Applet Example

/*
Basic Java Applet Example
 This Java example shows how to create a basic applet using Java Applet class.
 */
 import java.applet.Applet;
 import java.awt.Graphics;
 /*
 <applet code = "BasicAppletExample" width = 200 height = 200>
 </applet>
 */
 public class BasicAppletExample extends Applet{
 public void paint(Graphics g){
 //write text using drawString method of Graphics class
 g.drawString("This is my First Applet",20,100);
 }
 }

Java Applets Life cycle

/*
Applet Life Cycle Example
 This java example explains the life cycle of Java applet.
 */
  import java.applet.Applet;
 import java.awt.Graphics;
/*
 *
 * Applet can either run by browser or appletviewer application.
 * Define <applet> tag within comments as given below to speed up
 * the testing.
 */
 /*
 <applet code="AppletLifeCycleExample" width=100 height=100>
 </applet>
 */
 public class AppletLifeCycleExample extends Applet{
/*
 * init method is called first.
 * It is used to initialize variables and called only once.
 */
 public void init() {
 super.init();
 }
/*
 * start method is the second method to be called. start method is
 * called every time the applet has been stopped.
 */
 public void start() {
 super.start();
 }
 /*
 * stop method is called when the the user navigates away from
 * html page containing the applet.
 */
 public void stop() {
 super.stop();
 }
 /* paint method is called every time applet has to redraw its
 * output.
 */
 public void paint(Graphics g) {
 super.paint(g);
 }
 /*
 * destroy method is called when browser completely removes
 * the applet from memeory. It should free any resources initialized
 * during the init method.
 */
 public void destroy() {
 super.destroy();
 }
 }