Efficient methods???

Question

I have written this piece of code that reads the content of an
array of textfield.The content of the textfields represent one of
several instructions.They are read,broken into two parts and they
are looked up in a switch statement and if valid the appropriate
action is executed.Also,i want to be able to add more commands.At the moment i have to add to the switch statement.This works but i was wondering if there is a more efficient way to design it.e.g to create a class for each class instruction and let the program determine (at runtime) which of these classes to execute.And to add a new one all i have to do is create a new class.
Two ways have been suggested.I would appreciate
if someone can take a look at it and tell how and why
they are more efficient.
Thank you
p.s:the commands are
in the form of integers e.g. 0000.This is split into
two and passed to command as in:
int do11=00 do22=00
command(do11,do22)
My method
private class do implements ActionListener
{ public void actionPerformed(ActionEvent event)
  { for(km=start2;km<Size && Stop==false;km++)
    { String do1=read.substring(0,2);
      int do11=(int)(Integer.parseInt(do1));
      int rem=read.length()-2+2;
      String do2=read.substring(2,rem);
      int do22=(int)(Integer.parseInt(do2));
      Command(do11,do22);
public void Command(int code1,int code2)
{ switch(code1)
  { case 1:
    String copy11=MemoryContent[operand].getText();
    calculator2.setText("   "+copy11);
    break;
    case 2:
    int copy31=(int)(Integer.parseInt(MemoryContent[operand].getText   ()));
    int copy32=(int)(Integer.parseInt(calculator2.getText()));
    int sum=copy31+copy32;
    //calculator2 is a label
    calculator2.setText(sum+"");
    break;
    case 3:
    //do something
    break;
    case n:
//n indicates any other integer that may be added in future
    //do something
    break;
    default:
    error.setText("Invalid Command");
}Suggested method 1
http://forum.java.sun.com/thread.jsp?forum=4&thread=228069
partial to reply #4
Suggested method 2
class do ....
{  public interface CommandDo
{     public void doIt(int arg);
final  CommandDo[] cmds =
{    new CommandDo()
      {      public void doIt(int arg)
      {        ... do command 0....
    new CommandDo()
    {      public void doIt(int arg)
    {        ... do command 1....
    },  ... more commands ..
public void command(int cmd, int arg)
{   cmds[cmd].doIt(arg);
   }

Answer 1

I'm not sure what your code is doing but it sounds
like you need to use the command pattern.
What you need is a Command interface with an execute()
method. Now when you want to add new commands to your
system just implement the execute method a different
way. The next step is how you know which command to
execute. I think you have digits representing
commands so you need a HashMap with the key being the
digits and the value being an instance of the command
to execute when you see those digits. Your huge
switch statement becomes a simple hash lookup which
returns a command, then call the command's execute
method. I have not used this method myself as I have not had time to read up on it. However, I do have a link to a file that talks about it which I have not really had time to look in to. I really should get to it when I have the time.
http://www.javaworld.com/javatips/jw-javatip68_p.html