//  SystemCheckApplet.java  (c) Kari Laitinen

//  http://www.naturalprogramming.com

//  2008-11-17  File created.
//  2008-11-17  Latest modification.

/*

  This program shows how an applet can find out
  the properties of the Java Runtime Environment
  where it is being executed.

  In both Java-enabled browsers and the appletviewer,
  applets can read these system properties by invoking
  the System.getProperty( String key ) method:
 
  Key             Meaning
  ____________    ______________________________

  java.version    Java version number
  java.vendor     Java vendor-specific string
  java.vendor.url Java vendor URL
  java.class.version Java class version number
  os.name          Operating system name
  os.arch         Operating system architecture
  os.version      Operating system version
  file.separator  File separator (eg, "/")
  path.separator  Path separator (eg, ":")
  line.separator  Line separator 


  Applets are prevented from reading these system properties:

  Key              Meaning
  ____________     _____________________________

  java.home        Java installation directory
  java.class.path  Java classpath
  user.name        User account name
  user.home        User home directory
  user.dir         User's current working directory
*/

import java.awt.* ;
import javax.swing.JApplet ;

public class SystemCheckApplet extends JApplet
{
   public void paint( Graphics graphics )
   {
      super.paint( graphics ) ;

      int text_position_x  =  40 ;
      int text_position_y  =  50 ;

      graphics.setFont( new Font( "monospaced", Font.BOLD, 14 ) ) ;

      graphics.drawString( "Properties of your Java Runtime Environment:  ",
                           text_position_x, text_position_y ) ;
      graphics.drawString( "Java version number            "
                         + System.getProperty( "java.version" ),
                           text_position_x + 20, text_position_y +  30 ) ;
      graphics.drawString( "Java vendor                    "
                         + System.getProperty( "java.vendor" ),
                           text_position_x + 20, text_position_y +  50 ) ;
      graphics.drawString( "Java vendor URL                "
                         + System.getProperty( "java.vendor.url" ),
                           text_position_x + 20, text_position_y +  70 ) ;
      graphics.drawString( "Java class version number      "
                         + System.getProperty( "java.class.version" ),
                           text_position_x + 20, text_position_y +  90) ;
      graphics.drawString( "Operating system name          "
                         + System.getProperty( "os.name" ),
                           text_position_x + 20, text_position_y + 110 ) ;
      graphics.drawString( "Operating system architecture  "
                         + System.getProperty( "os.arch" ),
                           text_position_x + 20, text_position_y + 130 ) ;
      graphics.drawString( "Operating system version       "
                         + System.getProperty( "os.version" ),
                           text_position_x + 20, text_position_y + 150 ) ;
      graphics.drawString( "File separator                 "
                         + System.getProperty( "file.separator" ),
                           text_position_x + 20, text_position_y + 170 ) ;
      graphics.drawString( "Path separator                 "
                         + System.getProperty( "path.separator" ),
                           text_position_x + 20, text_position_y + 190 ) ;
      graphics.drawString( "Line separator                 "
                         + System.getProperty( "line.separator" ),
                           text_position_x + 20, text_position_y + 210 ) ;
   }
}