Cross-platform way to open a file using Java 1.5

Runtime.getRuntime().exec(new String[]{ "rundll32",
                          "url.dll,FileProtocolHandler", fileName });

Desktop desktop = Desktop.getDesktop();

 desktop.open( aFile );
 desktop.imaginaryAction( aFile );

package your.pack.name;

import java.io.File;

public class Desktop{

    // hide the constructor.
    Desktop(){}

    // Created the appropriate instance
    public static Desktop getDesktop(){

        String os = System.getProperty("os.name").toLowerCase();

        Desktop desktop = new Desktop();
         // This uf/elseif/else code is used only once: here
        if ( os.indexOf("windows") != -1 || os.indexOf("nt") != -1){

            desktop = new WindowsDesktop();

        } else if ( os.equals("windows 95") || os.equals("windows 98") ){

            desktop = new Windows9xDesktop();

        } else if ( os.indexOf("mac") != -1 ) {

            desktop = new OSXDesktop();

        } else if ( os.indexOf("linux") != -1 && isGnome() ) {

            desktop = new GnomeDesktop();

        } else if ( os.indexOf("linux") != -1 && isKde() ) {

            desktop = new KdeDesktop();

        } else {
            throw new UnsupportedOperationException(String.format("The platform %s is not supported ",os) );
        }
        return desktop;
    }

    // default implementation :(
    public void open( File file ){
        throw new UnsupportedOperationException();
    }

    // default implementation :(
    public void imaginaryAction( File file  ){
        throw new UnsupportedOperationException();
    }
}

// One subclass per platform below:
// Each one knows how to handle its own platform


class GnomeDesktop extends Desktop{

    public void open( File file ){
        // Runtime.getRuntime().exec: execute gnome-open <file>
    }

    public void imaginaryAction( File file ){
        // Runtime.getRuntime().exec:gnome-something-else <file>
    }

}
class KdeDesktop extends Desktop{

    public void open( File file ){
        // Runtime.getRuntime().exec: kfmclient exec <file>
    }

    public void imaginaryAction( File file ){
        // Runtime.getRuntime().exec: kfm-imaginary.sh  <file>
    }
}
class OSXDesktop extends Desktop{

    public void open( File file ){
        // Runtime.getRuntime().exec: open <file>
    }

    public void imaginaryAction( File file ){
        // Runtime.getRuntime().exec: wow!! <file>
    }
}
class WindowsDesktop extends Desktop{

    public void open( File file ){
        // Runtime.getRuntime().exec: cmd /c start <file>
    }

    public void imaginaryAction( File file ){
        // Runtime.getRuntime().exec: ipconfig /relese /c/d/e
    }
}
class Windows9xDesktop extends Desktop{

    public void open( File file ){
        //Runtime.getRuntime().exec: command.com /C start <file>
    }

    public void imaginaryAction( File file){
       //Runtime.getRuntime().exec: command.com /C otherCommandHere <file>
    }
}

public static boolean isWindows() {
	String os = System.getProperty("os.name").toLowerCase();
	return os.indexOf("windows") != -1 || os.indexOf("nt") != -1;
}
public static boolean isMac() {
	String os = System.getProperty("os.name").toLowerCase();
	return os.indexOf("mac") != -1;
}
public static boolean isLinux() {
	String os = System.getProperty("os.name").toLowerCase();
	return os.indexOf("linux") != -1;
}
public static boolean isWindows9X() {
	String os = System.getProperty("os.name").toLowerCase();
	return os.equals("windows 95") || os.equals("windows 98");
}

if (isLinux())
  {
     cmds.add(String.format("gnome-open %s", fileName));
     String subCmd = (exec) ? "exec" : "openURL";
     cmds.add(String.format("kfmclient "+subCmd+" %s", fileName));
  }
  else if (isMac())
  {
     cmds.add(String.format("open %s", fileName));
  }
  else if (isWindows() && isWindows9X())
  {
     cmds.add(String.format("command.com /C start %s", fileName));
  }
  else if (isWindows())
  {
     cmds.add(String.format("cmd /c start %s", fileName));
  }

final Program p = Program.findProgram(fileExtension);
p.execute(file.getAbsolutePath());

Program.launch("http://google.com/");

Display.syncExec(new Runnable() {
    public void run() {
        Program.launch("http://google.com/");
    }
});